MILKWEED FAMILY 375 



1. Asclepias cordifdlia (Benth.) Jepson. Purple Milkweed. Fig. 3837. 



Acerates cordifolia Benth. PI. Hartw. 323. 1849. 

 Asclepias ecornuta Kell. Proc. Calif. Acad. 1: 55. 1855. 

 Acerates atropurpurea Kell. Proc. Calif. Acad. 1: 65. 1855. 

 Gomphocarpus cordifolius A. Gray, Bot. Calif. 1 : 477. 1876. 

 Asclepias cordifolia Jepson, Fl. W. Mid. Calif. 384. 1901. 



Stems herbaceous, erect, 3-10 dm. high, from a stout woody root; herbage green often 

 tinged with purple, glabrous or more often minutely and rather sparsely puberulent with forked 

 hairs. Leaves opposite, cordate-clasping, broadly ovate to ovate-lanceolate, 6-15 cm. long, 2.5-9 

 cm. wide, acute or short-acuminate at apex ; umbels 1 to several at the apex and often in the 

 axils of the upper much-reduced bract-like leaves, few- to many-flowered ; pedicels glabrous or 

 sparsely pubescent ; calyx-lobes dark purple, thinly pubescent ; corolla-lobes dark red-purple, 

 oblong, 7-9 mm. long, glabrous on the back ; hood purplish, short-cylindric, open at the top and 

 cleft down the inner surface, truncate at apex, with the inner angles prolonged upward into 

 lanceolate tooth-like projections; follicles lanceolate, straight, divergent, long-acuminate, 10-14 

 cm. long; fruiting pedicels reflexed. 



Canyons and hillsides, especially in rocky situations, Upper Sonoran and Arid Transition Zones; Josephine 

 and Klamath Counties, southern Oregon, south to Solano County in the Coast Ranges and Kern County in the 

 Sierra Nevada, California, also western Nevada. Type locality: Marysville Buttes, Sutter County, California. 

 April-June. 



2. Asclepias californica Greene. California or Round-hooded Milkweed. 



Fig. 3838. 



Acerates tomentosa Torr. Bot. Mex. Bound. 160. pi. 44. 1859. Not Asclepias tomentosa Ell. 18'21. 



Gomphocarpus tomentosus A. Gray, Bot. Calif. 1: 477. 1876. Not Buch. 1822. 



Gomphocarpus tomentosus var. Xantii A. Gray, loc. cit. 



Asclepias californica Greene, Erythea 1 : 92. 1893. 



Gomphocarpus Torreyi J. F. Macbride, Contr. Gray Herb. No. 65:42. 1922. 



Gomphocarpus Torreyi var. Xantii J. F. Macbride, loc. cit. 



Stems herbaceous, erect, 3-7 dm. high ; herbage hoary with a dense woolly-arachnoid pube- 

 scence. Leaves opposite, oblong-lanceolate to broadly ovate, acute or short-acuminate to obtuse 

 at apex, obtuse to cordate at base, sessile or short-petioled, 3-15 cm. long, 2-8 cm. wide; umbels 

 sessile or on short peduncles, 6-12-flowered ; calyx-lobes and outer surface of corolla-lobes 

 white-woolly, the latter purple, 8-10 mm. long, hoods maroon, broadly ovoid, centrally attached 

 to the column, about 4 mm. high, distinctly shorter than the anthers, cleft dowm the back to a 

 little below the middle ; horns none ; follicles ovoid, acuminate, 7-10 cm. long, about 3 cm. thick, 

 white-woolly. 



Mostly in open woods, Upper Sonoran and Arid Transition Zones; Contra Costa County in the Coast 

 Ranges, and Mariposa County, in the Sierra Nevada, south to San Diego County, California. Type locality: 

 mountains east of San Diego, California. April-July. 



3. Asclepias cryptoceras S. Wats. Humboldt Milkweed. Fig. 3839. 



Acerates latifolia Torr. in Frem. Second Rep. 317. 1845. Not Asclepias latifolia Raf. 

 Asclepias cryptoceras S. Wats. Bot. King. Expl. 283. pi. 28. 1879. 

 Asclepias Davisii Woodson, Ann. Mo. Bot. Gard. 26: 261. 1939. 



Stems prostrate, 10-30 cm. high, more or less flattened; herbage glabrous, except on the 

 leaf-margins, bracts and calyx-lobes. Leaves opposite, broadly oval or suborbicular, 3-9 cm. 

 long, 2-7 cm. wide, rather thick and glaucous-green, rounded or shallowly subcordate at base, 

 rounded and often mucronate at apex, short-petioled ; umbels 2-Z, few-flowered, all at the 

 summit, the terminal short-peduncled, the lateral sessile and from the same node as the terminal 

 one, or rarely also from the node below ; corolla-lobes greenish yellow, ovate, 10-12 mm. long ; 

 hoods attached from the base of the column, saccate-ovoid, flesh-colored, equaling the anthers, 

 abruptly and minutely bi-acuminate at apex, cleft for a short distance down the back; horn 

 falcate-subulate, completely enclosed in the hood; fruiting pedicels decurved; follicles ovoid, 

 rather short-acuminate, 3-5 cm. long. 



Loose gravelly or rocky soils, Upper Sonoran and Arid Transition Zones; Grant County, eastern Oregon, 

 to Mono County, California, east to Wyoming and Colorado. Type locality: "West Humboldt Mountains, near 

 Humboldt Lake, rare; 5000 feet altitude," Nevada. April-June. 



4. Asclepias vestita Hook. & Arn. Woolly Milkweed. Fig. 3840. 



Asclepias vestita Hook & Arn. Bot. Beechey 363. 1838. 



Stems herbaceous, several, simple, 3-6 dm. high, herbage arachnoid-woolly, the umbels and 

 nascent parts densely so, more or less glabrate in age. Leaves opposite, ovate-lanceolate to 

 lanceolate, short-petioled, acute to subcordate at base, acute to acuminate at apex, 7-17 cm. 

 long ; umbels in the upper axils, usually 1-3 on a stem, the lateral sessile or on very short 

 peduncles many-flowered; pedicels slender and weak, 2.5-3 cm. long, densely hoary-arachnoid 

 at flowering time; corolla-lobes hoary on the back, 6-7 mm. long, cream-colored, or the tips 

 tinged with reddish purple ; hoods white, with a brown stripe down the middle of the outer 

 side, 3 mm. long, slit down the inner side, truncate at summit with the inner edge sharply acute 

 or somewhat auriculate ; horn about equaling or usually a little shorter than the hood, rather 

 blunt at the apex and only slightly incurved; wings of the anthers subtended by 2 small teeth„ 



