188 BOTANY. 



Water-hole near Tucson, Ariz., Rothrock, 1874 (700). Prom Western 



Texas to Southern California and Into Mexico. 



Am lewodoba* decumbejts, Gray, Proc. Amer. Acad 12, 66. (Anan- 



ihem decumbens, Xutt; Acetates decumbent, Deeaisne, Watson, Bot King.)— 



Santa I Y. \. Mex. (283), Rothrock, 1874. From Arkansas to Texas, 



Mexico, and Utah. 



Asclepias TUBEEOSA, L.— Willow Spring, Arizona (200), Rothrock, 



1874. Exactly like the common form of the States. Perhaps the most 



western locality of this beautiful species. 



Asclepias speciosa, Torn Ann. Lye. X. Y. 2, 218; Watson, I. 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 pirrple ;• 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. subvekticillata, 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. G94 from the same region. It approaches nearer to A. 

 M' .'nana 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 



•Am .i PIODORA, Gray.P.oe. Amer. Acad. 12, C6; Synops. 88. {Anantherix, in part, Nutt. ; Acerates 

 ... part, Deeaisne and othei8.)-Corolla rotate-spreading, afterwards closed ; hoods inserted over the 

 whole (short) oolumn, spreading and assurgent, sac-shaped, opward -J-,,]],,! by a salient crest. Anther- 

 wings corneous, narrowed a. base, angnlate above the middle ; pollinia dependent.-8tout, low peren- 

 nial herbs, with usually scattered leaves and large greenish flowers in BuhtermioaJ umbels. 



