MILKWEED FAMILY 377 



attached to the column; fruiting pedicels reflexed; follicles hoary when young, glabrate at 

 maturity, ovoid, about 6 cm. long and 2.5 cm. thick. 



Dry flats and slopes. Upper Sonoran Zone; South Coast Ranges and foothills of the Sierra Nevada, 

 California, from Stanislaus County to San Luis Obispo County, and from San Jpaquin and Calaveras Counties 

 to Fresno County; also reported from Carpenteria, Santa Barbara County. Type locality : California. Col- 

 lected by Douglas, probably in Monterey County or on his trip from Monterey to Santa Barbara. May-June. 



Asclepias vestita var. Parishii Jepson, Man. Fl. PI. Calif. 772. fig. 779. 1925. Less arachnoid, espe- 

 cially the inflorescence; leaves firmer more commonly ovate and rounded or subcordate at base, the arachnoid 

 pubescence becoming denuded at flowering time; pedicels 1.5-2.5 cm. long; flowers purple; the minute teeth 

 subtending the anther wings, sometimes more reduced. Western rim of the Mojave Desert, froin Antelope 

 Valley to Hesperia; also in Inyo County, according to Jepson. Type locality: Cajon Pass, San Bernardino 

 County. According to the specimens in the Parish Herbarium, Asa Gray proposed to name the variety atter 

 the desert, but his name was never published. 



5. Asclepias eriocarpa Benth. Kotolo or Indian Milkweed. Fig. 3841. 



Asclepias eriocarpa Benth. PI. Hartw. 323. 1849. 



Asclepias Fremontii Torr. ex A. Gray, Syn. Fl. N. Amer. 22; 93. 1878. 



Asclepias Kotolo E.&slyi. Zoe5:86. 1900; 5: 98. 1901. 



Stems herbaceous, simple and erect, 4-8 dm. high, herbage hoary-tomentose throughout. 

 Leaves opposite or at least some of them often in whorls of 3 or 4, broadly oblong to oblong- 

 lanceolate, 6-18 cm. long, 2.5-8 cm. broad, truncate to subcordate at base, rounded to obtuse at 

 apex; petioles seldom over 3-5 mm. long; umbels 1 or 2, or more commonly several in the 

 upper axils, all peduncles many-flowered ; pedicels 2-3 cm. long, densely white-woolly ; corolla- 

 lobes oblong-ovate, cream-colored, 4-5 mm. long ; hoods a little shorter than the anthers, cream- 

 colored or flushed with rose-purple ; horn broad at base, falcate, tapering to the pointed slightly 

 protruding apex; follicles 6-10 cm. long, 2-2.5 cm. thick, rather short-acuminate at apex, to- 

 mentose. 



Drv washes benches and slopes, Upper Sonoran and Arid Transition Zones; Mendocino and Shasta 

 Counties southward through the valleys and lower altitudes of the Sierra Nevada and Coast Ranges to northern 

 Lower California. At the southern end of the range the leaves are mostly narrower and usually acute at apex. 

 Type locality: "Tularcitos in vicinibus Monterey," California. May-Aug. 



6. Asclepias erosa Torr. Desert Milkweed. Fig. 3842, 



Asclepias erosa Torr. Bot. Mex. Bound. 162. 1859. 

 Asclepias leucophylla Engelm. Amer. Nat. 9: 348. 1875. 

 Asclepias leucophylla var. obtusa A. Gray, Bot. Calif. 1: 620. 1876. 

 Asclepias erosa var. obtusa A. Gray, Syn. Fl. N. Amer. 2^: 94. 1878. 

 Asclepias obtusata Greene, Leaflets Bot. Obs. 2: 232. 1912. 

 Asclepias Rothrockii Greene, loc. cit. 



Stems herbaceous, 5-8 dm. high, finely lanate, usually becoming thinly so or glabrate at 

 flowering time. Leaves glabrate and green in age, sessile, ovate to ovate-lanceolate, acute or 

 acuminate, cordate at base, 5-20 cm. long, 2 . 5-10 cm. wide, coriaceous, the margin minutely and 

 irregularly denticulate or eroded; umbels all peduncled, usually solitary and racemosely dis- 

 posed in the upper axils, the peduncles often forked at apex and giving rise to one or more 

 short secondary peduncles thus forming a compound umbel; pedicels numerous, very slender 

 and weak in anthesis, more or less densely white-woolly ; corolla-lobes greenish white, more or 

 less tomentose on the back, 5-6 mm. long ; hoods a little exceeding the stamens, broadly obovoid, 

 truncate at apex ; horn attached near the base of the hood, well-exserted and curved over the 

 stamens and stigma; follicles short-acuminate, 5-8 cm. long, 2-2.5 cm. thick, minutely tomen- 

 tose, patches of the white tomentum remaining on mature fruit simulate mildew. 



Open desert and Upper and Lower Sonoran Zones; Upper San Joaquin Valley and Inyo County, Cali- 

 fornia, south through the Mojave and Colorado Deserts to Lower California, east to Nevada, Utah, and Ari- 

 zona. 'Type locality: Metate, Gila River Valley, Arizona. April-Sept. 



7. Asclepias mexicana Cav. Narrow-leaved Milkweed. Fig. 3843. 



Asclepias mexicana Cav. Ic. 1: 42. pi. 58. 1791. 



Asclepias fascicularis Decne. in A. DC. Prod. 8:569. 1844. 



Stems erect, 5-10 dm. high, glabrous or sparsely puberulent. Leaves in whorls of 3-6, or 

 the lower and uppermost opposite, linear to linear-lanceolate, 6-15 cm. long, 4-20 mm. wide, 

 short-petioled ; umbels several in the upper axils, many-flowered; peduncles 2-5 cm. long; pedi- 

 cels 6-10 mm. long; flowers greenish white or the corolla-lobes often tinged with purple, these 

 oblong, 4-5 mm. long; hoods broadly ovate, 2 mm. long; horns subulate, well-exceeding the 

 hoods and incurved over the tops of the anthers; follicles lanceolate-acuminate, 6-9 cm. long; 

 seeds 6 mm. long, narrowly wing-margined, and irregularly reticulate-wrinkled. 



Dry ground. Upper Sonoran and Transition Zones; Spokane River, eastern Washington and northern 

 Idaho south through eastern and western Oregon and California to Lower California, east to Nevada and 

 Utah and through the Mexican Plateau region to near Mexico City, the type locality. June-Oct. 



8. Asclepias albicans S. Wats. White-stemmed or Wax Milkweed. Fig. 3844. 



Asclepias albicans S. Wats. Proc. Amer. Acad. 24: 59. 1889. 



Stems branching and shrubby, 1-3 m. high, the surface more or less covered with a thin 

 white exudation. Leaves caducous, in whorls of three, linear-filiform; umbels on peduncles 

 about 1.5 cm. long, many-flowered; pedicels exceeding the peduncles; bracts early deciduous, 

 these, the calyx and pedicels tomentose; corolla-lobes greenish white or sometimes tinged with 



