MILKWEED FAMILY 



107 



4. SOLANOA Greene 



Stems strongly flattened. Umbels small, terminal, globose, densely many-flow- 

 ered, the peduncles longer than the pedicels. Flowers purplish-red outside, flesb- 

 eolor within. Hoods cleft dorsally from top to bottom, the ventral side adnate to 

 the filament column. Horns none. — Species 1. (The Indian chief, Solano, of the 

 Suisunes.) 



1. S. purpurascens Greene. Ground Milkweed. (Fig. 351.) Stems 2 or 3 

 from a stout taproot, about 1 foot long, prostrate, flexuous, purplish and purple- 

 dotted; herbage eanescently puberulent; leaf -blades thick, the lowermost elliptic- 

 ovate, the upper broadly cordate-ovate, 1 to 2 inches long; petioles 1 to 2 lines long; 

 umbels 2 or 3; flowers about 2 lines long; hoods brownish-yellow, equaling the fila- 

 ment-column; follicles 2 inches long, about 5 

 lines in diameter at the widest part. /%V C 



Montane dry or rocky slopes on disintegrat- 

 ing serpentine, 2000 to 5000 feet : North Coa.st 

 Ranges from the Mayacamas Range to the Yollo 

 Bolly Mts. June. 



Hist. note. — Solanoa purpurascens was first discov- 

 ered in 1S74 by C. B. Towle of the Vallejo High School. 

 Asa Gray, who published the species, wrote of it as from 

 "Lake Co. near the Geysers." The Geysers are in north- 

 eastern Sonoma County, and if the plant were found near 

 the Geysers, the locality must be in the Mayacamas Eange 

 on the boundary between Sonoma County and Lake 

 Coimty. Towle gave his material of the species to E. L. 

 Greene, rector at Vallejo, who sent a portion to Asa Gray. 

 Greene had no specimens other than those of Towle and 

 doubtless well knew where his friend Towle collected 

 them, since he writes "mountain summits of Sonoma Co., 

 near the Geysers" (Man. Bot. Eeg. S. F. Bay 242,-1894). 

 It has, however, never been re-collected in the Mayacamas 

 Eange. As to our present knowledge Solanoa purpura- 

 scens remains a rare plant and is known to us only from 

 the following localities, all of which are in the Yollo Bolly 

 Mountains: Snow Mt., Lake Co. (traU to Summit Spr. 

 at Cedar Creek), M. S. Baker; Font's Sprs., w. Colusa 

 Co., Eattan; Foster Sheep Camp, Soldier Eidge, South 

 Yollo Bolly, Jepson 14,533. 



Eefs.— Solanoa pukpukascens Greene, Pitt. 2:67 

 (1890) ; Jepson, Fl. W. Mid. Cal. 384 (1901), ed. 2, 324 

 (1911), Man. 771 (1925). Gomphocarpus purpurascens 



Gray, Proc. Am. Acad. 10:76 (1874), type loc. "bare summit of a mountain in Lake Co., not far 

 from the Geysers," Towle (comm. Greene). Schizonotus purpurascens Gray, I.e. 12:66 (1876). 



Fig. 351. Solanoa purpusascens 

 Greene, a, flowering branch, X % ; 6, 

 fl., X 1%; c, hood, X 5; d, follicle, 



X V2. 



5. ASCLEPIAS L. Milkweed 



Stems commonly erect, arising from thick deep-seated roots. Bracts of the in- 

 volucre usually subulate. Calyx and corolla divisions reflexed, those of the former 

 small, persistent, those of the latter deciduous. Filament-column bearing a circle 

 of 5 hoods, each containing an incurved horn, or hornless. Anther wings (forming 

 the sides of the cloven gland) widened towards the truncatish base. Follicles ovate 

 or lanceolate, one often abortive, erect or ascending, or pendulous or descending 

 in A. subulata. Seeds anatropous, flat, margined, imbricated on the large placenta. 

 Embryo large, with broad foliaceous cotyledons in thin endosperm. — Species 80, 

 North and South America, Africa. (Asklepios, Greek name of the celebrated an- 

 cient physician of Asia Minor, Aesculapius.) 



A. Horns present in the hoods. 

 Hoods equaling or shorter than the anther-column. 



Leaves broad; follicles erect or ascending, on deflexed pedicels; herbage woolly, sometimes 

 glabrate in age. 



