ASCLEPIADACEAE. 



VOL. III. 



22. Asclepias verticillata L. Whorled Milk- 

 weed. Fig. 3404. 



Asclepias verticillata L. Sp. PI. 217. 1753. 



Roots slender, fascicled; stem slender, simple or 

 branched, pubescent in lines above, leafy, i-2j 

 high. Leaves narrowly linear, sessile, verticillate in 

 3's-7's or some of them alternate, glabrous or very 

 nearly so, their margins narrowly revolute ; umbels 

 numerous, many- flowered ; peduncles slender, i'-ii' 

 long; pedicels almost filiform, shorter than the pe- 

 duncles; corolla greenish white, its segments oblong, 

 ii"-2" long; column about i" high; hoods white, 

 oval, entire, about equalling the anthers, much 

 shorter than the subulate incurved horn; follicles 

 erect on the erect fruiting pedicels, narrowly spindle- 

 shaped, glabrous, 2'-$' long. 



In dry fields and on hills, Maine and southern On- 

 tario to Saskatchewan, south to Florida, Mexico and 

 _3_ New Mexico. July-Sept. 



23. Asclepias galioides H.B.K. Bedstraw Milk- 

 weed. Fig. 3405. 



Asclepias galioides H.B.K. Nov. Gen. 3 : 188. 1818. 



Glabrous, except the minutely pubescent stems and pedi- 

 cels. Stems erect, i high or more, from a horizontal root- 

 stock ; leaves erect or spreading, in whorls of 2-6, narrowly 

 linear, 2'-$' long, the margins revolute; peduncles longer 

 than the pedicels and shorter than the leaves ; umbels 

 9"-i3" in diameter ; flowers greenish-white ; corolla-seg- 

 ments 2" long; hoods as high as the anthers, broadly 

 rounded at the summit, dorsally hastate-sagittate, the ven- 

 tral margins slightly involute, entire; horn arising from 

 the base of the hood, long-exserted over the anthers ; 

 anther-wings minutely notched at the base; follicles erect 

 on erect fruiting pedicels, attenuated, 2'-2f long, glabrous 

 or minutely puberulent. 



Kansas to Colorado, Arizona and Mexico. May-July. 



24. Asclepias pumila (A. Gray) Vail. 

 Low Milkweed. Fig. 3406. 



Asclepias pumila Vail ; Britton & Brown, 111. Fl. 3 : 

 12. 1898. 



Asclepias verticillala var. pumila A. Gray, Proc. 

 Am. Acad. 12: 71. 1876. 



Stems 4'-io' high, tufted from a woody root. 

 Leaves very numerous, crowded, sometimes ob- 

 scurely whorled, filiform-linear, i'-2' long, 

 smooth or minutely roughened, the margins rev- 

 olute; umbels 2-several, short-peduncled, few- 

 flowered; pedicels filiform, puberulent, 3"-4" 

 long; corolla greenish white, its segments ob- 

 long, \\"-2" long; column short; hoods white, 

 erect, oblong, entire, equalling the anthers, 

 shorter than the slender incurved horn ; follicles 

 erect on erect fruiting pedicels, narrowly spindle- 

 shaped, ii'-3' long, finely puberulent. 



Dry plains, Iowa to South Dakota, Arkansas, 

 Texas, Wyoming, Colorado and New Mexico. 



