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Flora and Vegetation of the Tucson Mountains, Pima County, Arizona

Acanthaceae Acanthus Family

*Anisacanthus thurberi (Torr.) Gray. Desert honeysuckle.
Scattered shrub; very common along rocky washes and canyons; 715 & 1325 m (2350 & 4350 feet); flowers red & orange, March & June, October & December.

*Carlowrightia arizonica Gray.
Scattered subshrub; uncommon on rocky slopes and along washes; 730 & 1310 m (2400 & 4300 feet); flowers white with purple veins on throat, March & May.

*Justicia californica (Benth.) D. Gibson. [Beloperone californica Benth.]. Chuparosa.
Local subshrub; common along north slope of Safford Peak; 790 & 885 m (2600 & 2900 feet); flowers red & orange, March & April (November).

*Ruellia nudiflora (Engelm. & Gray) Urban.
Scattered herbaceous perennial; uncommon in washes and canyons, occasionally on rocky slopes; 700 & 1190 m (2300 & 3900 feet); flowers purple, (April & May), August & October.

*Siphonoglossa longiflora (Torr.) Gray.
Widespread subshrub; very common on rocky slopes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers white, March & May, August & November.
 

Adiantaceae Fern Family

*Cheilanthes lindheimeri Hook. Lindheimer lipfern.
Widespread fern; common in crevices on rocky slopes and cliffs in desertscrub and desert grassland; 790 & 1430 m (2600 & 4700 feet).

+Cheilanthes parryi (D. C. Eaton) Domin. [Notholaena parryi D. C. Eaton.]. Parry lipfern.
Local fern; limestone, south slopes of Twin Peaks ("Picacho Calero" R. R. Humphrey s.n. May 1931).

*Cheilanthes pringlei Davenp. Pringle lipfern.
Scattered fern; common in crevices on rocky slopes and cliffs; 695 & 1160 m (2280 & 3800 feet); note on J. J. Thornber 2542 in 1905 suggests the Tucson Mts. as the type locality.

*Cheilanthes wootonii Maxon. Beaded lipfern.
Local fern; uncommon in crevices on rocky north slopes, in desert grassland, Radio Towers and Wasson peaks and Tumamoc Hill; 855 & 1430 m (2800 & 4700 feet).

*Cheilanthes wrightii Hook. Wright lipfern.
Widespread fern; common in crevices on rocky slopes and cliffs; 640 & 1005 m (2100 & 3300 feet).

*Cheilanthes yavapensis Windham ined. Yavapai lipfern.
Local fern; common in crevices on rocky north slopes in desert grassland, Radio Towers Peak; 1325 & 1430 m (4350 & 4700 feet); very similar to C. wootonii.

*Notholaena cochisensis Goodd. [Notholaena sinuata (Sw.) Kaulf. var. cochisensis (Goodd.) Weatherby]. Helechillo.
Widespread fern; very common on limestone slopes, common on other rock types, in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet).

*Notholaena sinuata (Sw.) Kaulf. Wavy cloakfern.
Widespread fern; common in shady areas on rocky slopes and cliff bases in desertscrub and desert grassland; 810 & 1370 m (2650 & 4500 feet).

*Notholaena standleyi Maxon. Standley cloakfern.
Widespread fern; common in crevices on rocky slopes and cliffs in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet).

*Pellaea truncata Goodd. [P. longimucronata Hook.]. Cliff brake.
Widespread fern; common in crevices on rocky slopes and cliffs in desertscrub and desert grassland; 640 & 1370 m (2100 & 4500 feet).

Pellaea wrightiana Hook. [P. ternifolia (Cav.) Link var. wrightiana (Hook.) A.F. Tryon].
Local fern; rare in shady crevices on north & facing side of small drainage, 0.5 mile east of Sweetwater Trail trailhead; 295 m (2880 feet).

Agavaceae Agave Family

Agave americana L. var. expansa (Jacobi) Gentry. Century plant.
Local exotic leaf succulent; rare along large wash west of Tumamoc Hill, escape from cultivation; 750 m (2460 feet), flower pale yellow, June & August.

*Agave schotti Engelm. Shindagger, amole.
Local leaf succulent; abundant on rocky slopes in desert grassland, north of Gates Pass and Wasson Peak area; 1070 & 1430 m (3500 & 4700 feet); flowers yellow, May & November.

Dasylirion wheeleri Wats. Sotol.
Scattered leaf succulent; common on rocky slopes in desertscrub and desert grassland; 855 & 1430 m (2800 & 4700 feet); flowers cream, May & August.

*Yucca baccata Torr. var. brevifolia (Schott ex Torr.) Benson & Darrow. [Y. thornberi McKelvey]. Banana yucca, datil.
Local leaf succulent; common on rocky slopes in desertscrub and desert grassland, Radio Towers and Wasson peaks area; 930 & 1430 m (3050 & 4700 feet); flowers cream, April.

Yucca elata Engelm. Soaptree yucca.
Local leaf succulent; rare; isolated individuals, southwest of Tumamoc Hill and along Kinney Road near the southeast end of Brown Mt.; 745 m (2450 feet), 825 m (2700 feet); flowers white, May & June.

Aizoaceae Carpet Weed Family

Trianthema portulacastrum L. Horse purselane.
Scattered exotic annual; uncommon to very common in wet summers on rocky slopes and bajadas, often in disturbed soil; 640 & 1005 m (2100 & 3300 feet); flowers purple, August & September.
 

Amaranthaceae Amaranth Family

*Amaranthus fimbriatus (Torr.) Benth. var. denticulatus (Torr.) Uline & Bray.
Local annual; rare on gravelly flats, Las Lomas and southwest corner of SNM; 715 & 790 m (2340 & 2600 feet); August & September.

*Amaranthus fimbriatus (Torr.) Benth. var. fimbriatus. Fringed amaranth.
Widespread annual; common on rocky slopes and along washes and canyons; 640 & 1310 m (2100 & 4300 feet); August & November.

*Amaranthus palmeri Wats. Pigweed, quelite.
Widespread annual; common on rocky slopes, roadsides, disturbed sites, and along washes; 640 & 1430 m (2100 & 4700 feet); August & November.

*Amaranthus sp. nov. Tucson pigweed.
Scattered annual; common on rocky slopes in desertscrub and desert grassland; 790 & 1430 m (2600 & 4700 feet); September & November.

Gomphrena sonorae Torr. Ball clover, globe amaranth.
Local herbaceous perennial; rare on west & facing cliff base on Starr's Hill and Kinney Road north of Gates Pass Road; 815 & 980 m (2680 & 3220 feet); September & October.

*Tidestromia lanuginosa (Nutt.) Standl. Espanta vaqueras.
Widespread annual; very common on rocky slopes and along washes and canyons in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); August & November.
 

Anacardiaceae Cashew Family, Sumac Family

*Rhus aromatica Ait. var. pilosissima (Engler in DC.) Shinners. [R. trilobata Nutt.]. Skunk bush.
Local shrub; common in desert grassland, northeast slope of Wasson Peak and uncommon at Radio Towers Peak; 1310 & 1430 m (4300 & 4700 feet); April & May.

Rhus lancea L. African sumac.
Local exotic tree; rare along washes, west of Tumamoc Hill and wash near Speedway Blvd., escape from cultivation; 745 & 780 m (2450 & 2550 feet); February & March.
 

Apocynaceae Dogbane Family

*Haplophyton crooksii L. Cockroach plant.
Widespread subshrub; common on rocky slopes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers yellow, March & April and July & November.

Aristolochiaceae Birthwort Family

*Aristolochia watsoni Woot. & Standl. Pipe vine.
Scattered herbaceous perennial vine; uncommon on bajadas and along washes; 715 & 975 m (2350 & 3200 feet); flowers purple, (April) August & October.

Asclepiadaceae Milkweed Family

• *Asclepias nyctaginfolia Gray. Four o'clock milkweed. Local herbaceous perennial; rare along washes, Oeste Wash, Picture Rocks Retreat Wash, and Tumamoc Hill; 715 & 885 m (2350 & 2900 feet); flowers greenish yellow, July & September.
• *Cynanchum arizonicum (Gray) Shinners. [Metastelma arizonicum Gray]. Milkweed vine. Widespread woody vine climbing on shrubs; common on rocky slopes and along washes in desertscrub and desert grassland; 670 & 1325 m (2200 & 4350 feet); flowers cream, April & May, August & December; in 1906 J. J. Thornber designated Tumamoc Hill as the type locality (Sierra Tucson, C. G. Pringle s.n. in April or May of 1884).
• *Matelea parvifolia (Torr.) Woods. [Gonolobus parvifolius Torr.]. Milkweed vine. Widespread woody vine climbing on shrubs; uncommon on rocky slopes in desertscrub and desert grassland; 730 & 1430 m (2400 & 4700 feet); flowers dark purple, March & April.
• *Matelea producta Woodson. [Gonolobus productus Torr.]. Local woody perennial vine climbing on shrubs; rare, on east slope of Wasson Peak; 1400 m (4600 feet); flowers pale green, August.
• Sarcostemma cynanchoides Decne. ssp. cynanchoides. [Funastrum cynanchoides (Decne.) Schlechter]. Climbing milkweed. Local herbaceous perennial vine; rare, along moist ditch near northeast corner of Desert Lab. and at Greasewood Park; 730 & 760 m (2400 & 2500 feet); flowers purple and white, August.
• *Sarcostemma cynanchoides Decne. ssp. hartwegii (Vail) Holm. [Funastrum heterophyllum (Engelm.) Standl.]. Climbing milkweed. Scattered herbaceous perennial vine climbing on shrubs and trees; uncommon along washes and canyons; 670 & 945 m (2200 & 3100 feet); flowers purple and white, March & May, September & October.

Bignoniaceae Bignonia Family

• Chilopsis linearis (Cav.) Sweet. Desert willow. Local shrub; uncommon along washes and roadside, west of Tumamoc Hill; 730 m (2400 feet); flowers pink, May & August.
• *Tecoma stans (L.) H.B.K. Yellow trumpet bush. Local shrub; uncommon on rocky slopes and in steep drainages in desertscrub and desert grassland, Gates Pass, Hugh Norris and King Canyon Trail, and Safford and Wasson Peak area; 825 & 1400 m (2700 & 4600 feet); flowers yellow, August & November.

Boraginaceae Borage Family

• *Amsinckia intermedia F. & M. Fiddleneck. Widespread annual; very common on rocky slopes, bajadas, gravelly flats, and along washes in desertscrub and desert grassland; 640 & 1325 m (2100 & 4350 feet); flowers orange, January & April.
• *Amsinckia tessellata Gray. Fiddleneck. Local annual; rare along sandy wash near Ez & kim & in & zin picnic area, Sendero Esperanza Trail, and west of Sandario Road; 715 & 915 m (2350 & 3000 feet); flowers orange, January & April.
• *Cryptantha angustifolia (Torr.) Greene. Narrowleaf nievitas. Local annual; uncommon (common in 1992) on sandy flats, bajadas, and along sandy washes, Kinney Road in SNM, Las Lomas, Oeste Wash, and Tumamoc Hill; 670 & 790 m (2200 & 2600 feet); flowers white, March & May.
• *Cryptantha barbigera (Gray) Greene. Bearded nievitas. Widespread annual; very common on rocky slopes, bajadas, and along canyons and washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers white, February & April.
• *Cryptantha decipiens (Jones) Heller. Gravel nievitas. Local annual; uncommon along sandy washes, roadsides, and on disturbed sandy soil, Kinney Road and west of Sandario Road in SNM and Sendero Esperanza Trail; 670 & 1310 m (2200 & 4300 feet); flowers white, March & April.
• *Cryptantha maritima Greene. Whitehair nievitas. Local annual; common on slopes of Picture Rocks Pass, uncommon on limestone hill north of Twin Peaks, and rare in King Canyon, ; 640 & 825 m (2100 & 2700 feet); flowers white, February & April.
• *Cryptantha micrantha (Torr.) Johnst. Purpleroot nievitas. Local annual; rare, on sandy soil and washes, Oeste Wash, Tumamoc Hill, Sendero Esperanza Trail, and west of Sandario Road; 745 & 975 m (2450 & 3200 feet); flowers white, April.
• *Cryptantha nevadensis Nels. & Kenn. Nevada nievitas. Scattered annual; uncommon on sandy bajadas and along washes and canyons; 685 & 1310 m (2250 & 4300 feet); flowers white, February & April.
• *Cryptantha pterocarya (Torr.) Greene. Wingnut nievitas. Widespread annual; very common on rocky slopes, bajadas, gravelly flats, and along washes in desertscrub and desert grassland; 640 & 1325 m (2100 & 4350 feet); flowers white, January & April.
• *Harpagonella palmeri Gray. Widespread annual; uncommon to common on gravelly flats of bajada and gentle gravelly slopes; 685 & 1295 m (2250 & 4250 feet); flowers white, February & April.
• *Lappula redowskii (Hornem.) Greene. Stickseed. Scattered annual; common on gravelly flats and along washes; 700 & 975 m (2300 & 3200 feet); flowers white or pale blue, February & April.
• +Lappula texana (Scheele) Britt. Stickseed. Local annual; very common on mesas, Tucson (J. J. Thornber s.n. in April 1903 & March 1908) and flats southwest of Tumamoc Hill (J. E. Bowers in 1983); 755 m (2480 feet); flowers white or pale blue, March & April.
• *Pectocarya heterocarpa Johnst. Hairy & leaved combbur. Scattered annual; uncommon (common in 1992) on flats west of Sandario Road, Tumamoc Hill, Tohono O'odom harvest site in SNM; 670 & 760 m (2200 & 2500 feet); flowers white, March & April.
• *Pectocarya platycarpa Munz & Johnst. Broadnut combbur. Scattered annual; common in disturbed areas and on gravelly slopes (often with P. recurvata) in desertscrub and desert grassland; 640 & 1220 m (2100 & 4000 feet); flowers white, February & March.
• *Pectocarya recurvata Johnst. Archnut combbur. Widespread annual; very common on rocky slopes, gravelly flats, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers white, February & April.
• *Plagiobothrys arizonicus (Gray) Greene. Blood weed. Scattered annual; uncommon to common (very common in 1992) on gravelly and rocky slopes and in canyons in desertscrub and desert grassland; 685 & 1310 m (2250 & 4300 feet); flowers white, February & April.
• Plagiobothrys pringlei Greene. Popcorn flower. Local annual; common on mesas, Tucson (J. J. Thornber 533, 2206 in 1903 & 1908), rare on sandy creosote flats near Artesiano Road and in desertscrub on Sweetwater Trail in 1992; 650 & 915 m (2135 & 3000 feet) flowers white, March & April.
• *Tiquilia canescens (DC.) A. Richardson. [Coldenia canescens DC.]. Scattered subshrub; common on rocky slopes and gravelly bajadas; 730 & 975 m (2400 & 3200 feet); flowers lavender, (April) July & August.

Cactaceae Cactus Family

• *Carnegiea gigantea (Engelm.) Britt. & Rose. [Cereus giganteus Engelm.]. Saguaro. Widespread stem succulent; abundant on rocky slopes and bajadas; 640 & 1400 m (2100 & 4600 feet); flowers white, April & August, especially May.
• *Echinocereus fasciculatus (Engelm.) Benson. [E. fendleri Engelm. var. robustus L. Benson]. Hedgehog cactus. Widespread stem succulent; common on rocky slopes and bajadas in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers pink, March & July.
• *Echinocereus triglochidiatus Engelm. Claret cup. Local stem succulent; common on rocky slopes in desertscrub and desert grassland, Gates Pass and Radio Towers and Wasson peaks; 975 & 1430 m (3200 & 4700 feet); flowers red, May & August.
• *Ferocactus cylindraceus Orcutt. [Ferocactus acanthodes (Lemaire) Britt. & Rose]. California barrel cactus. Local stem succulent; rare on rocky slopes, Panther and Safford peaks area; 640 & 975 m (2100 & 3200 feet); flowers yellow striped with red below,, April & June (August & September).
• *Ferocactus cylindraceus Orcutt. x F. wislizenii (Engelm.) Britt. & Rose. Scattered stem succulent; common on rocky slopes in desertscrub and desert grassland, particulary on south slope of ridge north of Picture Rocks Road; 640 & 1400 m (2100 & 4600 feet); flowers yellow or orange, April & June, August & September.
• *Ferocactus wislizenii (Engelm.) Britt. & Rose. Fishhook barrel cactus. Widespread stem succulent; common on rocky slopes and bajadas in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers orange, occasionally red, July & September (November).
• *Mammillaria grahamii Engelm. [M. microcarpa Engelm.]. Fishhook pincushion. Widespread stem succulent; very common on rocky slopes, bajadas, and boulder crevices in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers pink and usually with white edges, March & September.
• *Mammillaria thornberi Orcutt. Thornber pincushion. Local stem succulent; uncommon on sandy bajadas near western boundary of SNM; 670 & 715 m (2200 & 2350 feet); flowers pink with white edges, April and September.
• *Mammillaria viridiflora (Britt. & Rose.) Bodeker. Fishhook pincushion. Local stem succulent; rare on rocky slopes in desertscrub and desert grassland, Hugh Norris and Sweetwater Trails and on Radio Towers Peak; 1005 & 1325 m (3300 & 4350 feet); flowers green & white, July.
• *Opuntia acanthocarpa Engelm. & Bigel. var. major (Engelm. & Bigel.) L. Benson. Buckhorn cholla. Widespread stem succulent; abundant on rocky slopes, bajadas, and gravelly flats in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers variable, March & May (August & September).
• Opuntia acanthocarpa Engelm. & Bigel. x O. spinosior (Engelm.) Toumey. Hybrid cholla. Local stem succulent; common on summit of Wasson Peak in desert grassland; 1430 m (4700 feet).
• Opuntia acanthocarpa Engelm. & Bigel. x O. versicolor Engelm. Hybrid cholla. Local stem succulent; rare on rocky slopes and gravelly flats, Gates Pass, Ina Road, and King Canyon Trail; 670 & 900 m (2200 & 2960 feet); flowers variable, April & May.
• *Opuntia arbuscula Engelm. Pencil cholla. Local stem succulent; very common on bajadas, west of Red Hills Information Center (SNM), in Sanctuary Cove area, and west of Silverbell Road north of Ina Road; 670 & 945 m (2200 & 3100 feet); flowers green, May.
• *Opuntia bigelovii Engelm. Teddy bear cholla. Scattered stem succulent; very common on rocky slopes; 670 & 1325 m (2200 & 4350 feet); flowers green, April & May.
• *Opuntia chlorotica Engelm. & Bigel. Pancake prickly pear. Scattered stem succulent; common on rocky slopes in desertscrub and desert grassland; 730 & 1430 m (2400 & 4700 feet); flowers yellow, April & June.
• *Opuntia fulgida Engelm. var. fulgida. Chainfruit cholla. Widespread stem succulent; very common on rocky slopes, bajadas, and gravelly flats; 670 & 1220 m (2200 & 4000 feet); flowers magenta, May & November.
• Opuntia fulgida Engelm. var. mammillata (Schott) Coult. Local stem succulent; rare on bajada, near jct. of Kinney and Sandario roads; 715 m (2345 feet); flowers magenta.
• Opuntia imbricata Haw. x O. versicolor Engelm. Hybrid Cholla. Local stem succulent; single plant in disturbed area, Las Lomas; 790 m (2600 feet), escape from cultivation, April & May.
• *Opuntia x kelvinensis Grant & Grant. [Opuntia fulgida Engelm. x O. spinosior (Engelm.) Toumey]. Hybrid cholla. Local stem succulent; uncommon on rocky slopes and bajadas around southwestern part of SNM; 700 & 790 m (2300 & 2600 feet); flowers magenta, May & June.
• *Opuntia leptocaulis DC. Christmas cactus. Widespread stem succulent; common to very common under trees and shrubs on rocky slopes, bajadas, and gravelly flats; 670 & 1310 m (2200 & 4300 feet); flowers pale yellow, March & May and August.
• Opuntia leptocaulis DC. x O. spinosior (Engelm.) Toumey. Hybrid pencil cholla. Local stem succulent; rare on flats near Sanctuary Cove, opposite ASDM, uncommon on Santa Cruz River flood plain south of Ina Road and east of Silverbell Road; 655 m (2150 feet); flowers pinkish white, May.
• Opuntia lindheimeri Engelm. var. linguiformis (Griffiths) L. Benson. [O. engelmannii Salm & Dyck var. linguiformis (Griffiths) Parfitt & Pinkava]. Cow's tongue prickly pear. Local exotic stem succulent; uncommon, Oeste Wash and SNM west of Sandario Road, escape from cultivation; 670 & 780 (2200 & 2550 feet), flowers yellow, April & May.
• Opuntia microdasys (Lehm.) Pfeifl. Bunny ears, nopal cegador. Local exotic stem succulent; common along banks of Oeste Wash north of Speedway Blvd. and rare in wash below Picture Rocks Retreat, escape from cultivation; 700 & 790 m (2300 & 2600 feet); flowers yellow with red tint, April & May.
• *Opuntia phaeacantha var. discata (Griffiths) Benson & Walkington. [O. engelmannii Salm & Dyck var. engelmannii]. Engelmann's prickly pear. Widespread stem succulent; abundant on rocky slopes and bajadas in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers yellow to orange, March & May.
• *Opuntia phaeacantha Engelm. var. major Engelm. Sprawling prickly pear. Widespread stem succulent; abundant on rocky slopes and bajadas; 670 & 1100 m (2200 & 3600 feet); flowers yellow, March & June.
• Opuntia santa-rita (Griffiths & Hare) Rose. [O. violacea Engelm. var. santa & rita (Griffiths & Hare) L. Benson]. Santa Rita prickly pear. Local stem succulent; rare on bajada 0.6 mile west of Silverbell Road on Ina Road, escape from cultivation; 670 m (2200 feet); flowers yellow, May.
• *Opuntia spinosior (Engelm.) Toumey. Cane cholla. Scattered stem succulent; common on bajadas; 655 & 945 m (2150 & 3100 feet); flowers variable, April & May (August).
• Opuntia spinosior (Engelm.) Toumey x O. versicolor Engelm. Hybrid cholla. Local stem succulent; uncommon on lower bajadas of Tumamoc Hill, abundant near Camino de Oeste and Sweetwater Drive, rare on steep slopes along Sweetwater Trail; 725 & 1005m (2380 & 3300 feet); flowers variable, April & May.
• Opuntia x tetracantha Toumey. [O. kleiniae DC. var. tetracantha (Toumey) W. T. Marshall, O. leptocaulis DC. x O. versicolor Engelm.]. Hybrid pencil cholla. Local stem succulent; rare on rocky slopes, opposite ASDM, Camp Cooper and on Tumamoc Hill; 750 & 870 m (2400 & 2850 feet); May.
• *Opuntia versicolor Engelm. Staghorn cholla. Widespread stem succulent; abundant on rocky slopes in southeastern part of range; 750 & 1070 m (2400 & 3500 feet); flowers variable, April & May (August).
• Opuntia vivipara Rose. Hybrid Cholla. Local stem succulent very common in desertscrub 0.6 miles west of Silverbell Road along Ina Road; 675 m (2210 feet); flowers burnt orange, April & May.
• Peniocereus greggii (Engelm.) Britt. & Rose. [Cereus greggii Engelm.]. Desert night & blooming cereus, reina de la noche. Probably scattered, but easily overlooked stem succulent; rare on bajadas and gravelly flats; 745 & 790 m (2450 & 2600 feet); flowers white, June.

Cannabaceae

• Cannabis sativa L. Marijuana, hemp. Local exotic annual; rare in disturbed desertscrub along Anklam Road at Starr Pass; 775 m (2540 feet); April.

Campanulaceae Bellflower Family

• *Nemacladus glanduliferus Jeps. Thread plant. Scattered (widespread in wet years) annual; uncommon on rocky slopes and along washes, common in wet years, 715 & 1145 m (2350 & 3750 feet); March & April.
• *Triodanis biflora (R. & P.) Greene. Local annual; rare east of Starr Pass (A. E. Garwood 4435 in 1973) and Safford Canyon (1991); 790 & 825 m (2600 & 2700 feet); flowers blue or purple, March & April.

Capparidaceae Caper Family

• Koeberlinia spinosa Zucc. Allthorn. Scattered shrub; uncommon to common on rocky slopes in southern half of range; 730 & 800 m (2400 & 2700 feet); flowers whitish, May & August.
• Polanisia dodecandra (L.) DC. ssp. trachysperma (T. & G.) Iltis. [P. trachysperma T. & G.]. Western clammyweed. Local annual; uncommon along wash west of Tumamoc Hill, Las Lomas, Oeste Wash, and Speedway and Anklam Roads; 715 & 870 m (2350 & 2850 feet); flowers white, May & August.

Caprifoliaceae Honeysuckle Family

• Sambucus mexicana Presl. Mexican elder. Local shrub; rare on septic tank northwest of the Desert Laboratory main building on Tumamoc Hill, possibly a remnant of Santa Cruz River riparian population: 810 m (2650 feet); flowers white, November.

Caryophyllaceae Pink Family

• +Herniaria cinerea DC. Burstwort. Local exotic annual; flats northwest of Tumamoc Hill (J. E. Bowers 2220 in 1983); 730 m (2400 feet), March.
• *Loeflingia squarrosa Nutt. Local annual; rare, just west of ASDM, Las Lomas, Oeste Wash, west of Sandario Road in SNM, and Tumamoc Hill; 715 & 855 m (2350 & 2800 feet), February & April.
• *Silene antirrhina L. Sleepy catchfly. Widespread annual; uncommon on rocky slopes and along washes in desertscrub and desert grassland; 730 & 1310 m (2400 & 4300 feet); flowers pink, February & April.

Chenopodiaceae Goosefoot Family

• *Atriplex canescens (Pursh) Nutt. Fourwing Saltbush, wingscale. Scattered shrub; common on gravelly and sandy flats, uncommon on rocky slopes; 670 & 1430 m (2200 & 4700 feet); March & May, August & November.
• *Atriplex elegans (Moq.) D. Dietr. ssp. elegans. Scattered annual or perennial herb; uncommon (common in 1992) on rocky slopes, disturbed soils, and along roadsides; 730 & 1430 m (2400 & 4700 feet); (March) July & October.
• *Atriplex linearis Wats. [A. canescens (Pursh) Nutt. ssp. linearis Hall & Clements]. Narrowleaf wingscale. Local shrub; common on gravelly flats near Santa Cruz River, rare on north slope of Safford Peak; 660 & 885 m (2170 & 2900 feet); September.
• Atriplex polycarpa (Torr.) Wats. Allscale. Local shrub; rare, jct. of Greasewood Road and Ironwood Hills Drive and jct. of Mile Wide and Sandario roads; common on gravelly flats, Santa Cruz River flood plain; 655 & 780 m (2150 & 2550 feet).
• Chenopodium berlandieri Moq. Pitseed goosefoot. Local annual; rare beside Anklam Road in desertscrub; 790 m (2600 feet); August.
• *Chenopodium incanum (Wats.) Heller. [C. fremontii Wats. var. incanum Wats.]. Goosefoot. Local annual; rare on rocky slopes in desertscrub and desert grassland, Wasson Peak area; 1390 & 1430 m (4560 & 4700 feet); May & August.
• Chenopodium murale L. Nettleleaf goosefoot. Local exotic annual; rare on roadsides and disturbed soils, Las Lomas and Tumamoc Hill; 790 & 870 m (2600 & 2850 feet); February.
• *Chenopodium neomexicanum Standl. New Mexican goosefoot. Widespread annual; commmon on rocky slopes and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); leaves fish & scented; (March) August & November.
• *Monolepis nuttalliana (Schult.) Greene. Poverty weed. Local annual; uncommon, Las Lomas, near Red Hills Information Center (SNM), and Tumamoc Hill; 750 & 870 m (2400 & 2850 feet); February & March.
• *Salsola australis R. Br. [S. iberica Sennen & Pau, S. kali L. var. tenuifolia (Tausch.) Aellen]. Russian thistle, tumbleweed. Widespread exotic annual; very common on disturbed soils; uncommon on rocky slopes and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); March & June, August & November.

Compositae Sunflower Family

• *Acourtia nana (Gray) Reveal & King. [Perezia nana Gray]. Desert holly. Scattered herbaceous perennial; common on bajadas under shrubs and trees; 760 & 915 m (2500 & 3000 feet); flowers purple, March & April (November).
• *Acourtia wrightii (Gray) Reveal & King. [Perezia wrightii Gray]. Brownfoot. Widespread herbaceous perennial; uncommon on rocky slopes and gravelly bajadas, often under trees and shrubs in desertscrub and desert grassland; 640 & 1325 m (2100 & 4350 feet); flowers purple, March & May (October).
• *Ambrosia ambrosioides (Cav.) Payne. [Franseria ambrosioiet); February & March (November).
• *Ambrosia deltoidea (Torr.) Payne. [Franseria deltoidea Torr.]. Triangleleaf bursage. Widespread subshrub; abundant on rocky slopes, bajadas, and gravelly flats; 640 & 1160 m (2100 & 3800 feet); March & May.
• *Ambrosia dumosa (Gray) Payne. [Franseria dumosa Gray]. White bursage, burro weed. Local subshrub; common on flats near northwest boundary of SNM; 670 & 745 m (2200 & 2450 feet); April (August).
• *Artemisia ludoviciana Nutt. ssp. albula (Wooton) Keck. White sage. Local herbaceous perennial; rare northwest of Trails End Canyon; 1325 m (4350 feet); September.
• *Artemisia ludoviciana Nutt. ssp. sulcata (Rydb.) Keck. White sage. Scattered herbaceous perennial; common on shaded slopes in desertscrub, common on rocky slopes, canyons, and washes in desert grassland; 670 & 1430 m (2200 & 4700 feet); September & November.
• +Aster subulatus Michx. var. ligulatus Shinners. [A. exilis Ell.]. Local annual; edge of pond near Tumamoc Hill landfill (J. E. Bowers 2731 in 1983); 750 m (2460 feet); rays white, September.
• *Baccharis brachyphylla Gray. Shortleaf baccharis. Local shrub; rare in desertscrub, Las Lomas area, David Yetman trail, and wash north of Hugh Norris Trail; 730 & 1050 m (2400 & 3450 feet); flowers whitish, September & October.
• *Baccharis salicifolia (R. & P.) Pers. [B. glutinosa Pers.]. Seep willow. Local shrub; common in King Canyon, uncommon at Radio Towers, Tumamoc Hill, and windmill at White horse Canyon; 745 & 1325 m (2450 & 4350 feet); flowers white, July & September.
• *Baccharis sarothroides Gray. Desert broom. Widespread shrub; very common in disturbed areas; 640 & 1005 m (2100 & 3300 feet); flowers whitish, October & November.
• *Bahia absinthifolia Benth. Widespread herbaceous perennial; common on rocky slopes, bajadas, and gravelly flats in desertscrub and desert grassland; 730 & 1430 m (2400 & 4700 feet); flowers yellow, August & May.
• *Baileya multiradiata Harv. & Gray. Desert marigold. Scattered herbaceous perennial; uncommon on dry slopes, bajadas, roadsides, and along washes, common west of Amole Peak on granitic ridge; 670 & 1310 m (2200 & 4300 feet); flowers yellow, February & June, August & December.
• *Bebbia juncea (Benth.) Greene. var. aspera Greene. Sweetbush, chuckwalla's delight. Scattered shrub; common on rocky slopes, bajadas, flats, and along washes in desertscrub and desert grassland; 670 & 1370 m (2200 & 4500 feet); flowers pale yellow, August & May.
• *Brickellia baccharidea Gray. Brickell & bush. Local subshrub; rare on rocky slopes and in boulder crevices, Hugh Norris Trail and Starr's Hill; 760 m (2500 feet), 975 m (3200 feet); flowers whitish, September & November.
• *Brickellia californica (T. & G.) Gray. Brickell & bush. Scattered shrub; rare to common on rocky slopes, canyons, and on cliff faces in desertscrub and desert grassland (uncommon in SNM); 730 & 1370 m (2400 & 4500 feet); flowers whitish, October & December.
• *Brickellia coulteri Gray. Brickell & bush. Widespread herbaceous perennial; very common on rocky slopes, bajadas, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers whitish, August & May.
• *Calycoseris parryi Gray. Yellow Tack stem. Local annual; uncommon on granitic slope along Hugh Norris Trail in desert grassland; 1230 m (4040 feet); flowers yellow, April.
• *Calycoseris wrightii Gray. Tackstem. Scattered annual; uncommon (very common in 1992) on rocky slopes and along washes; 745 & 1310 m (2450 & 4300 feet); flowers white, February & May.
• Centaurea melitensis L. Malta starthistle. Scattered exotic annual; common along roadsides; 730 & 990 m (2400 & 3250 feet); flowers yellow, March & May.
• *Chaenactis carphoclinia Gray. Pincushion flower. Local annual; rare on flats above Oeste Wash, wash near Picture Rocks cave, and near Trails End Road; 780 & 855 m (2550 & 2800 feet); flowers white, April.
• *Chaenactis stevioides H. & A. Pincushion flower. Widespread annual; very common on rocky slopes, bajadas, and along washes; 730 & 1265 m (2400 & 4150 feet); flowers white, February & April.
• *Cirsium neomexicanum Gray. Thistle. Scattered herbaceous perennial (biennial); common on rocky slopes in desertscrub and desert grassland; 790 & 1430 m (2600 & 4700 feet); flowers deep pink, March & June.
• +Conyza bonariensis (L.) Cronq. [Erigeron linifolius Willd.]. Local exotic annual; moist ditch at northeast base of Tumamoc Hill (J. E. Bowers 2723 in 1983); 730 m (2400 feet); flowers whitish, August.
• *Conyza canadensis (L.) Cronq. [Erigeron canadensis L.]. Horseweed. Local annual; rare, King Canyon and Sweetwater washes and moist ditch near northeast base of Tumamoc Hill; 730 & 930 m (2400 & 3050 feet); flowers whitish, (May) August & September.
• *Conyza coulteri Gray. [Laennecia coulteri (A. Gray) Nesom]. Local annual; common near water on Las Lomas and edge of pond near Tumamoc landfill, and rare in Sweetwater Canyon; 730 & 790 m (2400 & 2600 feet); flowers whitish, September.
• *Dimorphotheca sinuata DC. [D. aurantiaca Hort., not DC.]. African daisy. Scattered exotic annual; rare (uncommon in 1992) on gravelly bajadas, along washes, and ridge tops, escape from cultivation; 685 & 1220 m (2250 & 4010 feet); flowers yellow or orange, March.
• Dyssodia acerosa DC. [Thymophylla acerosa (DC.) Strother]. Local subshrub; uncommon on flats near Tumamoc Hill landfill; 745 m (2450 feet); flowers yellow, May.
• Dyssodia concinna (Gray) Rob. [Thymophylla concinna (Gray) Strother]. Local annual; mesas along road at foot of Cat Mt. (J. J. Thornber s.n. in May 1905 & in April 1913) and Tumamoc Hill landfill (P. D. Jenkins observation in 1987), 745 m (2450 feet); rays white; April & May; Kearney and Peebles (1960) suggest these areas were the type locality [Arizona, mesas near Tucson, C. G. Pringle in 1884].
• *Dyssodia pentachaeta (DC.) Rob. [Thymophylla pentachaeta (DC.) Small]. Parvialena. Widespread annual or perennial herb; common on roadsides, occasionally rocky slopes; 780 & 915 m (2550 & 3000 feet); flowers yellow, February & May, August & November.
• *Dyssodia porophylloides Gray. [Adenophyllum porophylloides (Gray) Strother]. San Felipe fetid marigold. Widespread subshrub; very common on rocky slopes in desertscrub, and uncommon on bajadas; 670 & 1370 m (2200 & 4500 feet); aromatic; rays yellow & orange, all months but July.
• *Encelia farinosa Gray. var. farinosa. Brittlebush, incienso. Widespread subshrub; very common to abundant on rocky slopes; 640 & 1370 m (2100 & 4500 feet); flowers yellow, November & May.
• *Encelia frutescens Gray. Green brittlebush. Local subshrub; rare on flats in southwest and junction of Sandario and Manville Roads; 670 & 950 m (2200 & 3120 feet); flowers yellow, April and August.
• *Ericameria cuneata (Gray) McClatchie. [Haplopappus cuneatus Gray]. Cuneate turpentine bush. Local subshrub or shrub; common among rocks and crevices, Rattlesnake Pass, Safford Peak, and Starr's Hill; 700 & 975 m (2300 & 3200 feet); flowers yellow, August & February.
• *Ericameria laricifolia (Gray) Shinners. [Haplopappus laricifolius Gray]. Turpentine bush. Widespread subshrub; very common to abundant on rocky slopes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); leaves turpentine scented; flowers yellow, August & May.
• *Erigeron colomexicanus A. Nels. Fleebane daisy. Local annual, uncommon on Wasson Peak; 1430 m (4700 feet); flowers white with pink tint, March & April.
• *Erigeron divergens T. & G. Fleabane daisy. Scattered annual; uncommon (very common on roadsides in 1992) on rocky slopes, bajadas, and along washes; 760 & 1100 (2500 & 3600 feet); rays white or purple, occasionally very short, February & May, September & November.
• *Erigeron lobatus A. Nels. Fleabane daisy. Local annual; uncommon on rocky slopes and along wash at Safford Canyon and Peak and Tumamoc Hill; 685 & 915 m (2250 & 3000 feet); rays white, February & May.
• *Eriophyllum lanosum Gray. Wooly eriophyllum. Scattered annual; common (abundant in 1992) on rocky slopes, bajadas, and flats; 640 & 1100 m (2100 & 3600 feet); rays white, February & April.
• *Eupatorium solidaginifolium Gray. Boneset. Widespread herbaceous perennial; common on rocky slopes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers cream to pale yellow, August & May.
• Evax multicaulis DC. Rabbit tobacco. Local annual; rare, Tumamoc Hill; 745 & 790 m (2450 & 2600 feet); March & April.
• *Filago arizonica Gray. Arizona filago. Local annual; rare (common in 1992), King Canyon, Las Lomas, ridge above Safford Canyon, and junction of Sandario and San Joaquin Roads; 700 & 1005 m (2300 & 3300 feet); March & April.
• *Filago californica Nutt. California filago. Scattered annual; rare (abundant in 1992) except common on Hugh Norris Trail and limestone hill north of Twin Peaks; 640 & 1005 m (2100 & 3300 feet); February & April.
• *Filago depressa Gray. Dwarf filago. Local annual; rare (common in 1992) in desertscrub on gentle slopes at Las Lomas, west of Sandario Road in SNM, and in disturbed wash near Signal Hill; 715 & 790 m (2350 & 2600 feet); March.
• +Gaillardia arizonica Gray. Blanket flower. Local annual; rare, Tumamoc Hill and flats west of Tumamoc Hill (F. Shreve s.n. in April 1935 and May 1939; D.K. Warren & R. M. Turner 68 & 61 in 1968; D. E. Goldberg & R. M. Turner 78 & 7 in 1978; J.E. Bowers 2428 in 1983); 745 m (2450 feet); flowers yellow, March & May.
• Gaillardia pulchella Foug. Blanket flower. Local annual; rare, Anklam Road near Starr Pass (P. D. Jenkins observation in 1987); 785 m (2580 feet); flowers orange, April.
• Gnaphalium leucocephalum Gray. White cudweed, gordolobo. Local herbaceous perennial; rare, Oeste Wash and atop Golden Gate Mt.; 780 & 1295 m (2550 & 4250 feet); flowers pearly white, September & October.
• Gnaphalium purpureum L. Purple cudweed. Local annual or perennial herb; rare under mesquite in rocky area, Las Lomas; 790 m (2600 feet); flowers purplish or brownish, April.
• *Gnaphalium wrightii Gray. Gordolobo, everlasting. Local herbaceous perennial; rare in desertscrub and desert grassland, Sweetwater Canyon, north slope of Safford Peak, and on Wasson Peak, common on Starr's Hill; 810 & 1430 m (2650 & 4700 feet); flowers pale yellow, (February) September & December.
• Gutierrezia arizonica (Gray) Lane. [Greenella arizonica Gray]. Scattered annual; rare on bajadas and flats; 670 & 790 m (2200 & 2600 feet); rays white, April.
• Gutierrezia microcephala (DC.) Gray. [incl. G. linioides Greene, G. lucida Greene]. Snakeweed. Local subshrub; common on rocky slopes, Gates Pass, Las Lomas, Kinney Road, and Tumamoc Hill; 790 & 1005 m (2600 & 3300 feet); flowers yellow, August & November.
• *Gymnosperma glutinosum (Spreng.) Less. [Selloa glutinosa Spreng.]. Tatalencho. Scattered subshrub; uncommon to common on rocky slopes and along washes in desertscrub and desert grassland; 945 & 1430 m (3100 & 4700 feet); flowers yellow, (May) September & January.
• Helianthus annuus L. Sunflower. Local annual; common along edge of disturbed field west of Rattlesnake Pass; 730 m (2400 feet); rays yellow, disk brown, August.
• Helianthus petiolaris Nutt. Sunflower. Local annual; rare on Kinney Road near ASDM; 790 m (2600 feet); rays yellow, disk brown, August & October.
• +Hemizonia kelloggii Greene. Tarweed. Local exotic annual; common weed about houses on mesas, Tucson (J. J. Thornber 386 in 1903 & s.n. in April and May 1905); flowers yellow, April & May.
• *Heterotheca psammophila Wagenkn. [H. subaxillaris (Lam.) Britt. & Rusby sensu K. & P.]. Camphor weed, telegraph plant. Widespread annual; very common on roadsides and disturbed areas; 700 & 975 m (2300 & 3200 feet); flowers yellow, August & October (may overwinter and bloom in spring in mild years).
• *Hymenoclea salsola T. & G. var. pentalepis (Rydb.) L. Benson. Cheesebush. Scattered subshrub; common on sandy flats and along washes; 670 & 1310 m (2200 & 4300 feet); March & April.
• *Hymenothrix wislizenii Gray. Widespread annual; common on roadsides and disturbed areas; 715 & 1005 (2350 & 3300 feet); flowers yellow, June & January.
• *Isocoma tenuisecta Greene. [Haplopappus tenuisectus (Greene) Blake]. Burro weed. Widespread subshrub; uncommon on rocky slopes and bajadas, common on disturbed soils and roadsides; 640 & 975 m (2100 & 3200 feet); flowers yellow, (June) August & December.
• *Iva ambrosiaefolia Gray. Scattered annual; uncommon along sandy washes and disturbed areas; 770 & 825 m (2520 & 2700 feet); September & November.
• Lactuca serriola L. Prickly lettuce. Local exotic annual; rare on gravelly flats, Las Lomas; 790 m (2600 feet); flowers pale yellow, April, August.
• +*Lasthenia californica DC. [Baeria chrysostoma F. & M.]. Goldfields. Local annual; Picture Rocks (J. J. Thornber 7734 in 1915) and Tumamoc Hill (J. J. Thornber 5307 in 1903); ca. 730 m (2400 feet); flowers yellow, April.
• +Layia glandulosa (Hook.) H. & A. Tiddy tips. Local annual; Gates Pass (L. Benson 10112 in 1940); rays white, April.
• Leucelene ericoides (Torr.) Greene. [Aster hirtifolius Blake, A. arenosus (Heller) Blake]. Local herbaceous perennial; rare on rocky and sandy slopes, Greasewood Park; 740 m (2420 feet); rays white, April.
• Machaeranthera asteroides (Torr.) Greene var. asteroides. [Aster tephrodes (Gray) Greene]. Local herbaceous perennial; rare on roadside of Silverbell; 690 m (2270 feet); rays purple, disk yellow, April.
• *Machaeranthera gracilis (Nutt.) Shinners. [Haplopappus gracilis (Nutt.) Gray]. Local annual; rare, Gates Pass and King Canyon; 885 & 1005 m (2900 & 3300 feet); flowers yellow, February & November.
• *Machaeranthera pinnatifida (Hook.) Shinners var. pinnatifida. [Haplopappus spinulosus (Pursh) DC.]. Spiny haplopappus. Widespread herbaceous perennial; uncommon on rocky slopes, gravelly bajadas, and disturbed areas; 640 & 1160 m (2100 & 3800 feet); flowers yellow, August & May.
• *Machaeranthera tagetina Greene. [Aster tagetinus (Greene) Blake]. Scattered annual; common on rocky slopes, gravelly flats, and roadsides; 790 & 1005 m (2600 & 3300 feet); rays purple, disk yellow, (March) August & November.
• *Malacothrix californica DC. var. glabrata Gray ex DC. Eaton. [M. glabrata Gray]. Desert dandelion. Scattered annual; uncommon on rocky slopes and bajadas; 685 & 1310 m (2250 & 4300 feet); flowers yellow, often striped with purple below, March & April.
• *Malacothrix clevelandii Gray. [M. sonorae Davis & Raven]. Yellow saucers. Scattered annual; rare (uncommon in 1992) under shade on rocky slopes and along washes and canyons; 745 & 1005 m (2450 & 3300 feet); flowers white to pinkish, March & April; holotype of M. sonorae from the Tucson Mts. (J. J. Thornber 362 in 1903).
• +Malacothrix coulteri Gray. Snakes head. Local annual; Tucson Mts. (J. J. Thornber 387, 4621 in 1903 & 1905); 790 m (2600 feet); flowers light yellow, April.
• *Malacothrix fendleri Gray. Local annual; rare on steep rocky slopes and disturbed roadside in desertscrub, ASDM, Apache Peak, and Sandario Road; 700 & 870 m (2300 & 2850 feet); flowers yellow, April.
• Matricaria matricarioides (Less.) Porter. Pineapple weed. Local exotic annual; rare, rocky slope west of Oeste Wash, Tumamoc Hill, and south of Ajo Way; March.
• *Microseris linearifolia (DC.) Schultz Bip. Silver puffs. Widespread annual; uncommon (very common in 1992) on rocky slopes, roadsides, and disturbed areas in desertscrub and desert grassland; 790 & 1430 m (2600 & 4700 feet); flowers yellow, March & April.
• *Monoptilon bellioides (Gray) H.M. Hall. Desert star. Scattered annual; common to uncommon on rocky gentle slopes and along washes; 640 & 915 m (2100 & 3000 feet); flowers white to lavender, February & April.
• *Parthenium incanum H.B.K. Mariola. Widespread subshrub; abundant on limestone and caliche, uncommon on other rock types, on rocky slopes and in canyons; 730 & 1220 m (2400 & 4000 feet); flowers white, August & November.
• Pectis cylindrica (Fern.) Rydb. Local annual; rare, Picture Rocks Retreat and Sonoran Desert Station; leaves aromatic; 725 & 855 m (2380 & 2800 feet); flowers yellow, September.
• *Pectis filipes Harv. & Gray. Local annual; rare on rocky slopes and in canyons in desertscrub and desert grassland, King Canyon and Wasson Peak area; 975 & 1370 m (3200 & 4500 feet); flowers yellow, August & November.
• *Pectis linifolia L. Local annual; rare on steep rocky slopes in desertscrub and desert grassland, Gates Pass and Hugh Norris Trail; 915 & 1430 m (3000 & 4700 feet); flowers yellow, September & October.
• *Pectis papposa Harv. & Gray. Chinchweed. Widespread annual; common in wet years on rocky slopes, bajadas, and beside washes; 640 & 1175 m (2100 & 3850 feet); leaves lemon scented, flowers yellow, August & November.
• *Perityle emoryi Torr. Rock daisy. Local annual; rare on steep rocky slopes and in boulder crevices at Panther Peak and Sus and Ez & Kim & In & Zin Picnic Areas (very common in 1992); 620 & 825 m (2240 & 2700 feet); rays white, January & April.
• *Perityle lemmonii (Gray) Macbride. [Laphamia dissecta Torr.]. Rock daisy. Local subshrub; common in crevices on cliffs at Rattlesnake Pass, Safford Canyon and Peak area, northwest of Picture Rocks pass, and Sus Picnic area; 695 & 975 m (2280 & 3200 feet); flowers yellow, January & June.
• *Porophyllum gracile Benth. Odora. Widespread herbaceous perennial; common on rocky slopes and gravelly bajadas; 670 & 1100 m (2200 & 3600 feet); aromatic; flowers purple & white, all months but June.
• +Prenanthella exigua (Gray) Rydb. [Lygodesmia exigua Gray]. Local annual; west base of Cat Mt. (V. M. Spalding & J. J. Thornber s.n. in April 1906), foothills, Tucson Mts. (J. J. Thornber s.n. in May 1903); 760 m (2500 feet); April & May.
• *Psilostrophe cooperi (Gray) Greene. Paper flower. Widespread herbaceous perennial; very common on rocky slopes and bajadas; 640 & 1310 m (2100 & 4300 feet); flowers yellow, August & May.
• *Rafinesquia californica Nutt. California chicory. Local annual; rare on steep rocky north slopes, King Canyon and Safford Peak; 990 m (3240 feet); flowers white, April.
• *Rafinesquia neomexicana Gray. Desert dandelion. Widespread annual; very common on rocky slopes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers white with purple veins on underside, February & May.
• Sanvitalia abertii Gray. Local annual; common in sand along small wash, near Oeste Wash; 790 m (2600 feet); flowers yellow, August & October.
• *Senecio douglasii DC. var. monoensis (Greene) Jepson. [S. monoensis Greene]. Sand wash groundsel. Widespread annual; uncommon on bajadas and along washes; 730 & 1310 m (2400 & 4350 feet); flowers yellow, January & April.
• *Senecio lemmonii Gray. Groundsel. Widespread herbaceous perennial; common on rocky slopes and along washes in desertscrub and desert & grassland; 730 & 1430 m (2400 & 4700 feet); flowers yellow, October & May.
• *Sonchus asper (L.) Hill. Spiny sow thistle. Local exotic annual; uncommon in washes and canyons and on slopes, King Canyon, Oxbow Road, and base of Safford Peak; 715 & 975 m (2350 & 3200 feet); flowers yellow, February & April.
• *Sonchus oleraceus L. Sow thistle. Local exotic annual; uncommon in disturbed areas, washes, and canyons, King Canyon Trail, Sweetwater Wash, and Tumamoc Hill; 715 & 975 m (2350 & 3200 feet); flowers yellow, March & April, October.
• *Stephanomeria pauciflora (Torr.) A. Nels. Desert straw. Widespread herbaceous perennial; common on rocky slopes, gravelly bajadas, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers pale lavender to purple, all year.
• Stylocline gnaphalioides Nutt. Everlasting nest straw. Local annual; rare, limestone hill north of Twin Peaks; 670 m (2200 feet); February.
• *Stylocline micropoides Gray. Desert nest straw. Scattered annual; uncommon (very common on slopes in 1992) on rocky slopes and along washes; 745 & 975 m (2440 & 3200 feet); March & April.
• +Stylocline sonorensis Wiggins. Sonoran nest straw. Local annual; sandy plain west of Tumamoc Hill (C. T. Mason Jr. & R. M. Turner 68 & 146 in 1968); 745 m (2450 feet); April.
• *Trixis californica Kellogg. Widespread subshrub; very common on rocky slopes, often under trees in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers yellow, August & May.
• Verbesina encelioides (Cav.) Benth. & Hook. Cowpen daisy. Local herbaceous annual or perennial; rare on rocky slopes and gravelly flats, ASDM, Gates Pass, Oxbow Road, and Tumamoc Hill; 715 & 915 m (2350 & 3000 feet); flowers yellow, April, August & September.
• *Viquiera annua (Jones) Blake. Annual goldeneye. Local annual; uncommon on rocky western slopes, King Canyon Road and Sweetwater Trail; 975 & 1170 m (3200 & 3840 feet); flowers yellow, September & November (may bloom all winter in mild years).
• *Zinnia acerosa (DC.) Gray. [Zinnia pumila Gray]. Desert zinnia. Widespread subshrub; very common on rocky slopes and gravelly bajadas in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); rays white, March & May, August & December.

Convolvulaceae Morning Glory Family

• Convolvulus arvensis L. Field bindweed. Local exotic herbaceous perennial; uncommon, south side of "A" Mt.; 750 m (2460 feet); flowers white with pink veins, April.
• *Evolvulus alsinoides L. Arizona blue eyes, dio de vibora. Widespread herbaceous perennial; common on rocky slopes and along washes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers blue & purple, occasionally albino, February & May, July & November.
• *Evolvulus nuttallianus Roemer & Schultes. [Evolvulus pilosus Nutt.]. Local herbaceous perennial; uncommon on ridgetops in desertscrub and desert grassland, jct. of King and Sweetwater Canyon trails, common between jct. of Hugh Norris and King Canyon trails and Wasson Peak; 1005 & 1430 m (3300 & 4700 feet); flowers purple, (April) July & September.
• *Ipomoea barbatisepala Gray. Morning glory. Scattered annual vine climbing on shrubs and trees; common in wet summers on rocky slopes and along washes in desertscrub and desert grassland; 640 & 1310 m (2100 & 4300 feet); flowers blue, August & November.
• *Ipomoea costellata Torr. Morning glory. Local annual vine; rare on rocky hill north of Wasson Peak; 1060 m (3480 feet); flowers purple, September.
• *Ipomoea cristulata Hallier f. [Ipomoea coccinea L.]. Scarlet creeper. Local annual vine climbing on other plants; common on rocky slopes and along washes and canyons in desertscrub and desert grassland, Panther, Radio Towers, and Wasson peaks, and King Canyon; 1035 & 1430 m (3400 & 4700 feet); flowers red, August & September.
• Ipomoea hederacea (L.) Jacq. [Ipomoea hirsutula Jacq. f., in part]. Morning glory. Scattered annual vine; common on rocky slopes and along washes and canyons; 790 & 1005 m (2600 & 3300 feet); flowers purple, September & December.
• Merremia dissecta (Jacq.) H. G. Hallier. Mile & a & minute vine. Local exotic woody vine; rare along wash, Tucson Estates, escape from cultivation; 800 m (2630 feet).

Crassulaceae Orpine Family

• *Tillaea erecta H. & A. [Crassula connata Miers]. Pigmy weed. Local annual; common in damp soil on flats near Oeste Wash, Safford Canyon, and junction of Rudasill and Sandario Roads; 685 & 855 m (2250 & 2800 feet); February & March.

Crossosomataceae Crossosoma Family

• *Crossosoma bigelovii Wats. Ragged rockflower. Widespread shrub; common on rocky slopes and in canyons and crevices of cliff faces in desertscrub and desert grassland; 685 & 1430 m (2250 & 4700 feet); flowers white, February & April, August & November.

Cruciferae Mustard Family

• *Arabis perennans Wats. Rock cress. Widespread herbaceous perennial; common on rocky slopes, rock crevices and along washes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers purple, February & May.
• Brassica campestris L. Field mustard. Local exotic annual; rare (single plant) along Picture Rocks Road; 685 m (2260 feet); flowers yellow, March.
• Brassica eruca L. [Eruca sativa Mill.]. Local exotic annual; rare on grounds of ASDM and Las Lomas; 790 & 865 m (2600 & 2840 feet); flowers white, February.
• +Brassica nigra L. Koch. Black mustard. Local exotic annual; vicinity of Snyder Hill, ca. 7 miles west of Tucson (A. E. Garwood 5112 in 1978); 800 m (2630 feet); flowers bright yellow, January.
• *Brassica tournefortii Gouan. Mustard. Scattered exotic annual; common on disturbed sites, uncommon on undisturbed rocky slopes; 640 & 1310 m (2100 & 4300 feet); flowers yellow, January & March.
• *Capsella bursa-pastoris (L.) Medic. Shepherd's purse. Local exotic annual; uncommon on rocky slope and roadsides, Hugh Norris Trail; 715 & 1050 m (2350 & 3450 feet); February & March.
• *Caulanthus lasiophyllus (H. & A.) Payson. [Thelypodium lasiophyllum (H. & A.) Greene]. Widespread annual; very common on rocky slopes, gravelly bajadas, and along washes; 670 & 1100 m (2200 & 3600 feet); flowers white, January & April.
• *Descurainia pinnata (Walt.) Britt. Tansy mustard. Widespread annual; very common on rocky slopes, bajadas, gravelly flats, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers white to pale yellow, February & May.
• *Descurainia sophia (L.) Webb. Flixweed. Local exotic annual; rare in dried pond one mile north of junciton of Sandario and Mile Wide Roads and ASDM; 715 & 870 m (2340 & 2850 feet); flowers pale yellow, April.
• *Draba cuneifolia Nutt. Whitlow grass. Widespread annual; common on rocky slopes, bajadas, and along washes, often under trees; 640 & 975 m (2100 & 3200 feet); flowers white, January & March.
• *Dryopetalon runcinatum Gray. Scattered annual; common on rocky slopes and among boulders in canyons in desertscrub and desert grassland; 745 & 1325 m (2450 & 4350 feet); flowers white, February & April.
• *Lepidium lasiocarpum Nutt. Sand peppergrass. Widespread annual; very common on rocky slopes, gravelly flats, disturbed soils, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers white, December & May.
• *Lepidium medium Greene. Peppergrass. Scattered annual; common (abundant at Las Lomas in 1992) along Sweetwater Trail; 700 & 1280 m (2300 & 4200 feet); flowers white, January & April.
• Lepidium thurberi Wooton. Peppergrass. Local perennial?; rare along Ironwood Hill Road; 695 m (2280 feet); flowers white, Feburary & November.
• *Lesquerella gordonii (Gray) Wats. Gordon bladderpod. Widespread annual; common on rocky slopes, bajadas, and along washes and canyons in desertscrub and desert grassland; 640 & 1310 m (2100 & 4300 feet); flowers yellow, January & April.
• *Lesquerella purpurea (Gray) Wats. White bladderpod. Widespread herbaceous perennial; common on rocky slopes and along washes and canyons in desertscrub and desert grassland; 790 & 1370 m (2600 & 4500 feet); flowers white with purple throat, November & April (August).
• Matthiola longipetala (Vent.) DC. var. bicornis Sibth. & Smith. [Matthiola bicornis (Sibth. & Smith) DC]. Evening stock. Local exotic annual; common on disturbed soils, south side of Tumamoc Hill, and Kinney Road; 745 & 975 m (2450 & 3200 feet); flowers purple with white, February & April.
• *Sisymbrium irio L. London rocket. Widespread exotic annual; common in all communities; 640 & 1370 m (2100 & 4500 feet); flowers yellow, January & May.
• *Sisymbrium orientale L. Tumble mustard. Local exotic annual; rare (common in 1992), Speedway Blvd. near Anklam Road and Trails End Road, west and east of Sandario Road in SNM, and junction of Kinney and Gates Pass Roads; 745 & 1005 m (2450 & 3300 feet); flowers yellow, February & April.
• *Streptanthus carinatus Wright. [incl. Streptanthus arizonicus Wats.]. Silverbells. Widespread annual; very common on rocky slopes, gravelly bajadas, and along washes in desertscrub and desert grassland; 640 & 1430 m (2100 & 4700 feet); flowers cream, January & April.
• *Thysanocarpus curvipes Hook. [Thysanocarpus amplectans Greene]. Lacepod. Widespread annual; common on rocky slopes and along washes in desertscrub and desert grassland; 670 & 1430 m (2200 & 4700 feet); flowers white, January & April.

Cucurbitaceae Gourd Family

• *Apodanthera undulata Gray. Coyote melon, Melon loco. Local herbaceous perennial vine; single plant on north & facing rocky granitic slope along Hugh Norris Trail, ca. 10 miles west of Tucson (A. E. Garwood 3808 in 1971), and mesas, Tucson (J. J. Thornber 5259 in 1903); 810 & 1005 m (2650 & 3300 feet); flowers yellow, July.
• *Citrullis vulgaris Schrad. Watermelon. Local exotic annual; rare in Tohono O'odham Indian saguaro fruit harvest area; 715 m (2340 feet).
• *Cucurbita digitata Gray. Coyote gourd. Scattered herbaceous perennial vine, often climbing up other plants; uncommon on sandy flats and along washes; 695 & 1005 m (2280 & 3300 feet); flowers yellow, July & August.
• *Echinopepon wrightii (Gray) Wats. Wild balsam apple. Local annual vine; common on steep rocky slope at base of cliffs, Safford Peak; 990 & 1005 m (3250 & 3300 feet); flowers white, July & October.
• *Tumamoca macdougalii Rose. Tumamoc globeberry. Probably scattered but easliy overlooked, herbaceous perennial vine, climbing on shrubs and trees; uncommon in desertscrub, near Mile Wide Road at west boundary of SNM, Oxbow Road, near Pima Community College, and north base of Tumamoc Hill; 655 & 790 m (2150 & 2600 feet); flowers pale yellow to greenish yellow, July & September; Tumamoc Hill is the type locality (D. T. MacDougal s.n. in July 1908).

Cuscutaceae Dodder Family

• +Cuscuta salina Engelm. Dodder. Local annual parasite; mesas, near Tucson (J. J. Thornber 7516 in 1913); flowers whitish, September.
• Cuscuta tuberculata Brandegee. Dodder. Local annual parasite on Boerhaavia erecta; very common 0.3 miles south of ASDM on Kinney Road; 855 m (2800 feet); flowers white, August.
• Cuscuta umbellata H.B.K. var. reflexa (Coult.) Yunker. Dodder. Local annual parasite on Tribulus terrestris and Atriplex elegans; very common at intersection of Silverbell and St. Mary's roads, disturbed soil; 715 m (2340 feet); flowers whitish, August.
• Cuscuta umbellata H.B.K. var. umbellata. Dodder. Local annual parasite on Trianthema portulacastrum; common on Tumamoc Hill landfill; 750 m (2460 feet); flowers white, August.

Cyperaceae Sedge Family

• +Cyperus alternifolius L. Flat sedge. Local exotic herbaceous perennial; along moist ditch northeast of Tumamoc Hill (R. M. Turner 83 & 10 in 1983), escape from cultivation; 730 m (2400 feet); April.
• *Cyperus esculentus L. Yellow nutsedge. Local herbaceous perennial; abundant in wet area in King Canyon, 925 & 940 m (3040 & 3080 feet); September.
• Cyperus rotundus L. Purple nutsedge. Local exotic herbaceous perennial; common on roadside 0.25 mile west of Silverbell Road on Speedway Blvd; 715 m (2340 feet); September.
• Cyperus squarrosus L. [Cyperus aristatus Rottb.]. Flatsedge. Local annual; common in canyons (Gatuño, Safford, and Sweetwater canyons) 885 & 945 m (2900 & 3100 feet); August & September.
• +Scirpus maritimus L. var. paludosus (A. Nels.) Koyama. [S. paludosus A. Nels.]. Salt marsh bulrush. Local herbaceous perennial; Tumamoc Hill landfill (T. L. Burgess 6269 in 1981; J. E. Bowers 2729 in 1983); 750 m (2460 feet); September & November.