388 ASCLEPIADACEAE (MILKWEED FAMILY) 



horn: follicles cinereous-pubescent. From southern Colorado and Arizona to 

 Texas, thence eastward to Florida and Canada. Known commonly as BUTTER- 

 FLY-WEED or PLEURISY ROOT. 



2. Asclepias incarnate L. 1. c. 215. Stem slender, 6-12 dm. high, leafy 

 to the top: leaves acuminate, 8-15 cm. long, the primary nerves not wide- 

 spreading: umbels usually numerous, many-flowered; pedicels pubescent: 

 corolla red or rose-purple, rarely white, its lobes oblong, about 4 mm. long; 

 horns incurved, longer than the hoods, obtuse, pink or purplish: anther-wings 

 entire, or obscurely notched at the base: fruiting pedicels erect or incurved; 

 follicles erect, 5-9 cm. long, sparingly puberulent. Within our range and 

 thence far eastward and southward. 



3. Asclepias cryptoceras Wats. King's Rep. 283. 1871. Glabrous; stems 

 decumbent, 2-3 dm. long, simple: leaves 3-4 pairs, rounded-ovate, 3-5 cm. 

 long, on very short petioles: umbels axillary and terminal, sessile, few-flowered: 

 corolla-lobes ovate-lanceolate, spreading, greenish-yellow, 10mm. long; hoods 

 of the crown 6 mm. long, equaling the disk, purple, ovate, abruptly pointed 

 with two short recurved beaks; horn short, incurved, not at all exserted: fol- 

 licles 3-5 cm. long. Western Wyoming to Nevada and Oregon. 



4. Asclepias latifolia (Torr.) Raf. Atl. Journ. 146. 1832. Puberulent 

 when young, soon green and glabrous: leaves about 5 pairs, approximate, very 

 thick and large, orbicular or broadly oval, often emarginate and with a mucro, 

 subcordate at base, nearly sessile, copiously transversely veined: umbels 2 

 or 3, all or mostly lateral, densely many-flowered; flowers greenish: column 

 very short but distinct; hoods barely equaling the anthers, broad, with a 

 truncate entire summit, which is equaled by the upper margin of the falci- 

 form triangular crest, the apex of which extends into a short subulate horn 

 partly over the top of the stigmatic disk. A. Jamesii. Plains of Colorado to 

 Arizona and Texas. 



5. Asclepias speciosa Torr. Ann. Lye. N. Y. 2: 218. 1826. Finely canescent- 

 tomentose: leaves subcordate-oval to oblong, thickish: pedicels of the many- 

 flowered dense umbel and the calyx densely tomentose; flowers purplish, 

 large: corolla-lobes ovate-oblong; hoods spreading, the dilated body and its 

 short inflexed horn not surpassing the anthers, but the center of its truncate 

 summit abruptly produced into a lanceolate-ligulate, thrice longer termination; 

 column hardly any: wings of the anthers notched and obscurely corniculate 

 at base. From Nebraska and Arkansas westwaid across the continent. 



6. Asclepias arenaria Torr. Bot. Mex. Bound. 162. 1859. Lanuginous- 

 tomentose, in age glabrate; stems thickly leaved: leaves smaller, coriaceous 

 when old, obovate or oval and retuse or the lower ovate, with rounded or 

 subcordate base, somewhat undulate, distinctly petioled: umbels all lateral, 

 rather densely many-flowered: corolla greenish-white; column nearly half the 

 length of the anthers; hoods about as broad as high, surpassing the anthers, 

 truncate at base and summit, the latter oblique and notched on each side 

 near the inner angle, which forms an obtuse tooth; horn with included ascend- 

 ing portion or crest broadly semilunate, as high as the hood; the abruptly in- 

 curved apex subulate-beaked, horizontally exserted, or the slender termina- 

 tion ascending. On sandbanks; southeastern Colorado to New Mexico. 



7. Asclepias Hallii Gray, Proc. Am. Acad. 12: 69. 1876. Puberulent- 

 glabrate; stem stout: leaves thickish, ovate-lanceolate or oblong-lanceolate, 

 with rounded base and rather acute apex, short-petioled, the stout midrib 

 and straight veins prominent underneath: umbels few and corymbose, many- 

 flowered, on peduncles somewhat longer than the pedicels: corolla greenish- 

 white and purplish; hoods elongated-oblong in outline, entire, hastately 2- 

 gibbous above the narrower base, a little surpassing the sickle-shaped horn: 

 anther-wings unappendaged at base. (A. curvipes A. Nels. Bull. Torr. Bot. 

 Club 28: 229. 1901.) Southern Wyoming and Colorado. 



8. Asclepias brachystephana Engelm. Torr. Bot. Mex. Bound. 163. 1859. 

 Stems 2-3 dm. high, very leafy, cinereous-puberulent or tomentose when 

 young, the inflorescence more floccose-tomentose : leaves lanceolate with a 

 broader rounded base to linear, short-petioled, very much surpassing the 



