﻿178 Vail: Studies in. the Asclepiadaceae 



4. Asclepias subverticillata (A. Gray). 



Asclepias verticillata, var. galioides Torr. Mex. Bound. Surv. 



164. 1859. In part. 



Asclepias vsrticillata, var. subverticillata A. Gray, Proc. Am. 



Acad. 12: 71. 1876. In part. 



Glabrous except the minutely pubescent stems and pedicels. 

 Stems slender, erect, 2-3 dm. high, from a slender vertical root- 

 stock, simple or branched ; internodes at the base of the stems 

 5-10 cm. long ; leaf-scars remaining conspicuous : leaves crowded, 

 opposite above, otherwise verticillate in threes or fours ; blades 

 narrowly linear, 4-10 cm. long, 1-2 mm. wide, acute at each end, 

 coriaceous, with a whitish midvein : umbels 4—8, lateral and ter- 

 minal, 2-2.5 cm - * n diameter, corymbosely disposed at or near the 

 summit of the stem, commonly many-flowered : peduncles longer 

 than the minutely pubescent pedicels and considerably shorter than 

 the upper often elongated leaves : corolla-segments greenish-white, 

 4-5 mm. long, obtuse or acutish : column nearly 1 mm. high : 

 hoods erect-spreading, nearly as high as the anthers, dorsally has- 

 tate-sagittate at the base, broadly rounded at the summit, the ven- 

 tral margins rounded, not angled at the slightly involute middle : 

 anther-wings narrow, very slender, prominently sagittate at the 

 minutely notched base : follicles 8 cm. long, slender, long-acumi- 

 nate, minutely puberulous : seeds about 4 mm. long ; coma 2 cm. 

 long. Mature fruit not seen. 



New Mexico: Wright, no. i6 86,_i8si-H2. in Herb. Columbia 

 University. Western Texas : Wright , u mountain valley beyond the 

 Limpia, Aug. 26th/' no. jjj>£V and " valley, 20 miles beyond the 

 Pecos, Aug. 17," no. 551, 1849 m Herb. Gray. Arizona: Fort 

 Verde, E. A. Mearns, no. 235, in Herb. Columbia University. 



Asclepias verticilla'a, var. subverticillata was established by Dr. 

 Gray, based " chiefly " on Asclepias verticillaia y var. galioides Torrey 

 (Mex. Bound. Surv. 164. 1859). In that publication Dr. Torrey 

 bases his variety on a specimen of Parry's from Sonora and New 

 Mexico, and on three numbers of Charles Wright's collection of 

 1851-52, nos. 1685, 1686 and 1689, adding that "our plant seems 

 to be the same as Hartweg's no. 216." Specimens of these last- 

 mentioned numbers are preserved in the Herbaria of Columbia 

 University, Harvard University, and the U. S. Nat. Museum. I 

 am not sure that I have seen Parry's specimen, which, according 

 to the copy of the Report of the Mexican Boundary Survey an- 



