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 

 jranched, pubescent in lines above, leafy, l-2j 

 high. Leaves narrowly linear, sessile, vcrticillate in 

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

 nearly so, their margins narrowly revolute ; umbels 

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

 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 

 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'-3' 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'-2l' 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, III. Fl. 3 : 

 12. 1S98. 



Asclepias verticillata 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, 1/-2' long, 

 smooth or minutely" roughened, the margins rev- 

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

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

 long; corolla greenish white, its segments ob- 

 long, i4"-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, 1Y-3' long, finely puberulent. 



Dry plains. Iowa to South Dakota. Arkansas, 

 Texas, Wyoming, Colorado and New Mexico. 



