MILKWEED FAMILY 



111 



Dry hills, 500 to 5000 feet : Inyo Co. ; southern Sierra Nevada in Kern Co.; up- 

 per San Joaquin Valley; Mohave and Colorado deserts and bordering ranges. 

 East to Utah and Arizona. May-July. 



Field note. — The white sap is collected by the Coahuillas in a vessel, allowed to solidify and 

 then chewed. "Its bitter taste disappears after a little and a tasteless gum is left which affords 

 inexhaustible satisfaction to the user." — Barrows, Etlmo-Bot. Coahuilla Indians, 7. 



Locs. — Upper San Joaquin Valley: Earlimart, Tulare Co., Hoover 2675; Edison, Kern Co., 

 Hoover 668 ; Caliente, Kern Co., Jones. Southern Sierra Nevada in Kern Co. : Kernville, K. Bran- 

 degee. Inyo Co.: Panamint Mts. (Contrib. U. S. Nat. Herb. 4:149) ; Silver Lake, Parish 10,376. 

 Mohave Desert: Cima, Jepson 15,843; Bagdad, K. Brandegee ; Calico Mts., Jepson 4808; Fair- 

 mount, Antelope Valley, Hall 6710. Colorado Desert: Lookout Mt., n. of Indio, Jepson 5977; 

 Palm Sprs. of San Jacinto, Jepson 6064 ; Palm Canon, San Jacinto Mts., Jepson 1346 ; Silent 

 Canon, se. end of Santa Eosa Mts., Jepson 11,714; betw. Kane Spr. and Oasis, C. V. Meyer 411; 

 San Felipe Wash, e. San Diego Co., Jepson 8896 ; Carrizo Creek, sw. Colorado Desert, T. Brandegee. 



Eefs. — AscLEPlAS EROSA Torr., Bot. Mex. Bound. 162 (1859), type loc. Metate, Gila River 

 valley, Ariz., Schoti, Tlmrher; Jepson, Man. 773 (1925). A. leucophylla var. obtusa Gray, Bot. 

 Cal. 1:620 (1876), type loc. Bartlett's Canon, Santa Barbara Co., BothrocTc (a form with very 

 obtuse leaves). A. erosa var. ohtusa Gray, Syn, FI. 2 :94 

 (1878). 



4. A. mexicana Cav. Narrow-leaf Milk- 

 weed. (Fig. 355.) Stem slender, 2 to 4 (or 7) 

 feet high; herbage glabrous; leaf -blades linear 

 to linear-laueeolate, in whorls of 3 to 6, or the 

 lower and uppermost opposite, 2i/2 to 6 inches 

 long, 2 to 6 (or 9) lines broad, short-petioled ; 

 umbels many, often in whorls or corymbose, 

 densely many- flowered, on peduncles longer than 

 the pedicels; flowers small, greenish-white or 

 tinged with purple; corolla-lobes oblong, 2 lines 

 long; hoods about equaling the stamen-column; 

 horns slender, subulate, exserted and incurved 

 over the summit of the disk; follicles lanceolate, 

 3 to 4 inches long, about 4 lines thick at the wid- 

 est part; seeds Si/^ Hues long. 



Forming colonies in dry ground of valleys 

 and foothills, 1 to 6500 feet : almost throughout 

 California but mostly absent from the deserts 

 and not on the immediate coast northward. 

 North to Washington, east to Utah, south to Mex- 

 ico. June-Sept. 



Field note. — Asclepias mexicana has an evil reputation among stockmen. The herbage is 

 doubtless poisonous to cattle, but is only mildly toxic as compared with Asclepias galioides of 

 Arizona and New Mexico. The plant propagates by underground roots, especially under cultiva- 

 tion, and in some places tends to become a minor agricultural pest. Small colonies have been 

 knovi-n to persist for 70 years in cultivated fields in Vaca Valley. In this particular A. speciosa 

 holds a similar record. From the juice of A. mexicana the native tribes obtained a gum which 

 they used for adhesive purposes. 



Locs. — Inyo Co.: Silver Caiion, White Mts., Jepson 7419; Bishop, comm. C. L. Hill; Lone 

 Pine, Jepson. Sierra Nevada: Lost Lake, Modoc Co., L. S. Smith 1034; Wbitmore, Shasta Co., 

 A. A. Weigart; Manton, Tehama Co., Jepson; Martin Sprs., Eagle Lake, Brown 4" fVieslander 

 31; Belden, Plumas Co., Jepson; Hetch-Hetehy, Jepson; Mono Hot Sprs., South Fork San Joa- 

 quin River, A. L. Grant 1496; Markwood Mdw., Fresno Co., Jepson; Hospital Rock, Middle Fork 

 Kaweah River, W. Fry. Great Valley: Redding, BlanTcinship ; Chico, Button; Norman, Glenn 

 Co., Davy ; Vacaville, Jepson 8411 ; Union Isl., San Joaquin Co., Jepson 10,277 ; Four-mile Slough, 

 cent. Fresno Co., Jepson 13,317; Greenfield, near Bakersfield, Davy 1855. Coast Ranges: Hupa, 

 Humboldt Co., Manning ; Mail Ridge, n. Mendocino Co., Jepson 16,525; Walker Valley, Mendo- 

 cino Co., Jepson; Hopland, Jepson: Wilbur Sprs., sw. Colusa Co., Jepson; Alexander Valley, So- 

 noma Co., Jepson 9487 ; Guinda, Yolo Co., Eowena Beans; Cordelia, Jepson 3078 ; Milpitas, It. J. 

 Smith; San Luis Obispo, Summers 539. S. Cal.: Lompoc, comm. C. TV. Beers; Victorville, Parish 

 10,602; Ojai Valley, Olive Thacher 33a; Los Angeles, E. D. Palmer; San Antonio Canon, San 

 Gabriel Mts., Peirson 149; San Bernardino, Parish; Anaheim Creek, Orange Co., Booth 1291; 



Fig. 355. Asclepias mexicana 

 Cav. o, fl. branchlet, X % ; 6, hoods 

 and stamen-column seen from above, 

 X 2; c, fl., X 2. 



