﻿180 Vail: Studies in the Asclepiadaceae 



and Herb. Canby ; San Diego, Miss Mary B. Croft, no. 209 in 

 Herb. Columbia University. 



The specimen on which Asclepias linearis Scheele was based is 

 said to grow " gesellshaftlich auf schwarzem Thonboden und 

 feuchter Prairie bei Neubraunfels : Lindheimer, Aug." A speci- 

 men from that region growing in " hard, clayey soil, N. Br." col- 



lected by 



:pias linifolia, no. 63 1 , J 



185 1, is preserved in Herb. Gray. It is annotated by Dr. Gray as 

 Asclepias verticillata var. snbverticillata. It is undoubtedly the 

 plant described by Scheele, and is more nearly related to Asclepias 

 vcrticillata than the other plants which have passed as so-called 

 varieties. An Asclepias vcrticillata, var. linearis has recently been 

 established by C. L. Pollard (Bull. Tor. Bot. Club, 24 : 156. 1856), 

 but the specimens so labeled which have come to us are only de- 



plants described by Scheele. 



•jpias verticellata and not the 



In Roemer and Schultes, Syst. 6: 70. 1820 under Asclepias 



tifolia 



an " Ascl. linearis." I have 



not been able to trace this species and retain the name for the 

 Texan plant until I can determine to what species the earlier pub- 

 lication of it applies. 



6. Asclepias linifolia H.B.K. Nov. Gen. et Sp. 3: 190. 1818. 



Asclepias salicifolia Lodd. Bot. Cab.//. 272. 1823. 



Asclep 

 A low 



Name only in Herb. Gray. 



and pedicels. Stems erect, 4-6 dm. or 1 m. high, solitary or several 

 together or 1-2 or more at intervals from a stout rootstock, com- 

 monly branched, minutely pubescent, mostly in lines above : leaves 

 opposite, tapering to a slender petiole ; blades narrowly linear, 7-14 

 cm. long, 2-3 or 4 cm. wide, acute at each end, glabrous ; mar- 

 gins often revolute ; midvein whitish, the widest leaves with ob- 

 scure but ascending veins : umbels lateral, several, on peduncles 

 longer than the 1 cm. long pedicels, several to many-flowered : 

 corolla-segments greenish-white, 3.5-4.5 mm. long, acutish : hoods 

 erect, white, one -third higher than the anthers, rounded at the 

 summit, dorsally hastate-sagittate at the base; ventral margins 

 lightly involute, entire ; horn flat, falcate, adnate to the keel of 

 the hood from the base up to about the middle, long-exserted 



