188 BOTANY. 
Water-hole near Tucson, Ariz., Rothrock, 1874 (7 wee From Western 
Texas to Southern California sid into Mexico. 
ASCLEPIODORA* DECUMBENS, Gray; Proc. Amer. Acad. 12, 66. (Anan- 
therix decumbens, Nutt.; Acerates decumbens, Decaisne, Watson, Bot. King.)— 
Santa Fé, N. Mex. (283), Rothrock, 1874. From Arkansas to Texas, New 
Mexico, and Utah. 
AscuLepias TuBEROSsA, L.— Willow Spring, Arizona (200), Rothrock, 
1874. Exactly like the common form of the States. Perhaps the most 
western locality of this beautiful species. 
Asciepias speciosa, Torr. Ann. Lye. N. Y. 2, 218; Watson, 7. c. 
282.—Willow Spring, Arizona (249), Rothrock, 1874. 
ASCLEPIAS INVOLUCRATA, Engelm. Bot. Mex. Bound. 163; Gray, Syn. 
94.—Minutely pubescent when young, at last glabrate; several weak, 
spreading stems from a stout root less than a span long; leaves opposite or 
alternate, lanceolate-linear, tapering, on short petioles, the broader ones with 
-a roundish, the others with a tapering base, the uppermost involucrating 
the mostly solitary, sessile, or short-peduncled umbel, and commonly over- 
topping it; flowers greenish with purple; ovate hoods rather longer than 
the anthers, the short incurved horn slightly exserted from about. their 
middle; pods ovate, acuminate, smooth, pubescent.—Algodones, N. Mex. 
(78), Rothrock, 1874; also in Arizona and adjacent Mexico. 
ASCLEPIAS VERTICILLATA, L., var. SUBVERTICILLATA, Gray, Proc. Am. 
Acad. 12, 71; Syn. 97.—Taller and stouter than the usual form, with leaves 
3-5’ long, opposite or ternate; peduncles alternate all along the stem, many 
times longer than the pedicels ; flowers rather larger than those of the 
ordinary form.—Algodones, N. Mex. (77), Rothrock, 1874. Very similar 
to Fendler’s No. 694 from the same region. It approaches nearer to A. 
Mexicana than to any of our varieties, but is readily distinguished by the 
scattered (not subterminal) umbels, the flat leaves, with slightly revolute 
margins, etc. The roots of all the forms of verticillata are fascicled, the 
*ASCLEPIODORA, Gray, Proc. Amer. Acad. 12, (6; Syrops. €8. (Anantheriz, in part, Nutt.; Acerates, 
Decaisne and others.)—Corolla rotate-spreading, afterwards closed ; hoods inserted over the 
whole dou cases column, spreading and assurgent, sac-shaped, upward 2-celled by a salient crest. Anther- 
ous, narrowed at base, argulate above the middle; pollinia dependent.—Stout, low, peren- 
nial coents with usually scattered leaves and large greenish iswers 3 in subterminal umbels. 
