108 



ASCLEPIADACKAK 



Lateral umbels sessile, or short-peduncled, the terminal one peduncled ; hoods truncatish, 

 a pair of slender teeth inserted between them on the stamen-column ; horns 

 wing-like, attached by their whole length to the dorsal side of the hoods within, 



not exserted; cismontane 1. A. vestita. 



Umbels all peduncled ; hoods more or less truncate, sometimes obliquely so, no teeth-like 

 processes between them. 

 Hoods saccate ; horns crest-like, attached dorsally aU the way to the summit of the 

 hood, the acute or sickle-shaped apex barely projecting or included; cis- 

 montane 2. A. eriocarpa. 



Hoods spreading ; horns attached at base of hood or below middle, strongly exserted, 

 curving over the disk of the stigma ; transmontane deserts and upper San 



Joaquin Valley 3. A. erosa. 



Leaves narrow or none ; follicles erect, on erect pedicels ; herbage glabrous. 



Stems very leafy ; hoods rounded at apex, the horns much exserted ; filament-column 



about as long as the anther-column ; throughout Cal 4. A. mexicana. 



Stems naked at flowering time, the leaves early deciduous ; hoods truncate at apex, the 

 horns scarcely exserted; filament-column shorter than the anther-column; Colo- 

 rado Desert 5. A. albicans. 



Hoods twice or thrice as long as the anther-column ; filament-column very short or none ; pedicels 

 deflexed in fruit. 



Hoods open, long-lanceolate above the broad base, very conspicuous; widely distributed 



6. A. speciosa. 

 Hoods with the sides closely appressed, the horn a wing-like crest attached towards the apex ; 

 Mohave and Colorado deserts. 



Leaves broad; stems decumbent - 7. A. nyctaginifoUa. 



Leaves narrow or none ; stems erect, rush-like 8. A. subulata. 



B. No horns to the hoods; pedicels deflexed in fruit. 



Hoods rounded, cleft half-way Aovna. the back, shorter than the anther-column ; filament-column 

 long; herbage white-tomentose 9. A. calif ornica. 



Hoods conical, open down the front, a little exceeding the anther-column; filament-column short; 

 herbage glabrous 10. A. cordifolia. 



1. A. vestita H. & A. Woolly Milk- 

 weed. (Fig. 352.) Stems several from tlie 

 root-crown, erect or ascending, % to 2 feet 

 high ; herbage white-woolly, the wool at length 

 largely deciduous; leaves in whorls of 2, the 

 leaf -blades ovate or mostly oblong-lanceolate, 

 often subcordate at base, 2 to 6 inches long, 

 the upper more acuminate, all short-petioled 

 or the ujjper sessile; umbels 1 to 4, the lateral 

 sessile or very short-peduncled, the terminal 

 peduncled; corolla yellowish-white or pur- 

 plish, tomentose on the outside, its lobes 3 

 lines long; hoods marble-white, aging yellow, 

 truncate at summit and entire, auriculate- 

 lobed or acute at the inner angle and open 

 down the front, bearing a longitudinal brown 

 band on the back, about as long as the stamen- 

 column; cloven glands with a pair of linear 

 teeth inserted beneath them on the stamen- 

 column; horn or crest blunt, not exserted, at- 

 tached to the back of the hood from the base 

 to the summit, produced upward and forward 

 into a short blunt point; follicles ovate, acute, 

 2i/'2 inches long, 1 inch wide. 



Dry plains and low hills, 50 to 4000 feet : 

 Sierra Nevada foothills from San Joaquin Co. 

 to Fresno Co. and the bordering San Joaquin Valley plain; South Coast Ranges 

 from western Stanislaus Co. to Monterey Co. and San Luis Obispo Co.; Santa Bar- 

 bara Co. Apr. -May; fr. Aug. 



Fig. 352. AscLEPiAS vestita H. & A. 

 o, fl. branchlet, X % ; b, hood, X 6 ; c, 

 long. sect, of hood, X 6; <?, follicle, 

 X%. 



