510 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Pedicels deflexed in fruit; flowers dull purplish or 
whitish; plants lower, 50 cm. high or less, 
spreading, much branched near the base. 
Hoods longer than the anthers; flowers green- 
ish white. .........-222..2.00-2222-. 7. A. involucrata. 
Hoods shorter than the anthers; flowers pur- 
plish. 
Hoods about half as long as the anthers; 
umbels pedunculate...........-.-. 8. A. brachystephana. 
Hoods only slightly shorter than the an- 
thers; umbels subsessile... .....- 9. A. uncialis. 
Leaves broadly oblong to orbicular, mostly obtuse or retuse. 
Fruit echinate; leaves acute or acutish.............. 10. A. speciosa. 
Fruit smooth; leaves obtuse or retuse. 
Stems very short, 5 cm. long or less; leaves as 
broad as long or broader........-.....-.---- 11. A. nummularia. 
Stems 20 cm. long or more; leaves usually much 
longer than broad. 
_ Leaves thin, glabrous, more or less glaucous, 
sessile or clasping...............----.- 12. A. elata. 
Leaves very thick, more or less tomentose, at 
least when young, never glaucous, 
short-petiolate. 
Stems, pedicels, and young leaves densely 
tomentose... ........2..22-------- 13. A. arenaria. 
Stems, pedicels, and leaves sparingly 
tomentose or glabrous..........-... 14. A. latifolia. 
1. Asclepias macrotis Torr. U.S. & Mex. Bound. Bot. 164. pl. 45, 1859. 
Tyre Locauiry: ‘Rocky hills near El Paso, and on the mountains below San 
Elceario,’’ Chihuahua. 
Rance: Western Texas and southern New Mexico and southward. 
New Mexico: Mangas Springs; Kingston; Organ Mountains; Buchanan; Sandia 
Mountains. Dry, rocky hills, in the Upper Sonoran Zone. 
2. Asclepias quinquedentata A. Gray, Proc. Amer. Acad. 12: 71. 1876. 
Asclepias quinquedentata neomexicana Greene, Proc. Amer. Acad. 16: 103. 1880. 
TypE LocALITy: San Pedro River, western Texas. 
Rance: Western Texas to Arizona. 
New Mexico: Coolidge; Mogollon Creek; Gilmores Ranch. Transition Zone. 
3. Asclepias pumila (A. Gray) Vail in Britt. & Brown, Illustr. Fl. 3: 12. 1898. 
Asclepias verticillata pumila A. Gray, Proc. Amer. Acad. 12: 71. 1876. 
Type Locauiry: ‘‘The western dry plains from Nebraska to New Mexico.” 
Rance; South Dakota and Arkansas to Colorado and New Mexico. 
New Mexico: Cabra Springs; Nara Visa; Gavilan Creek; Leachs. Plains and low 
hills, in the Upper Sonoran Zone. 
4. Asclepias galioides H. B. K. Nov. Gen. & Sp. 3: 188. 1818. 
Tyrer Locauity: ‘‘Crescit in temperatis Regni Novae Hispaniae, inter Valladolid 
de Mechoacan et locum Cuiseo.’’ 
Rance: Kansas and Colorado to Arizona, western Texas, and Mexico. 
New Mexico: Common throughout the State. River valleys and wet grounds, in 
the Lower and Upper Sonoran zones. 
