﻿Vail: Studies in the Ascleim adaceae 173 



middle, truncately rounded to the base, entire or minutely notched : 

 follicles 6 cm. long, erect on recurved pedicels, 2 cm. long, ob- 

 liquely ovate-acuminate, tomentulose, parallel-veined, tinged with 

 reddish purple: seeds 13 mm. long, 1 cm. wide, broadly obovate, 

 body light brown, marked with irregularly broken ridges converg- 

 ing to the axis ; border 2 mm. wide, tan-colored, corrugated-ru- 

 gose ; coma 2 cm. long, copious. 



Utah: Court House Wash, May, 1892; Willow Creek, San 

 Juan Co., July, 1895. 



Differing from A. involucrata in its larger size and stouter 

 habit ; broader, longer, and more coriaceous leaves, and much 

 larger follicles and seeds. The differences in the horns and anthers 

 are shown in the figures. The dorsal angle of the hood is more 

 pronounced in A. involucrata and thicker. These two species are 

 closely related ; but since the differences appear to run through all 

 parts and the vegetative distinctions are readily recognized, it 

 seems best, as Miss Vail has suggested, to regard this as a distinct 

 species. 



I!.— NOTES ON ASCLEPIAS VERTIGILLATA AND SOME NEARLY RELATED SPECIES. 



In the large amount of material pertaining to Asclepias 

 verticillata and its two varieties which has passed through my 

 hands during the past year, several recurring forms have convinced 

 me that there are more than a single species with two forms to be 

 segregated from it. I am not at all prepared to say that I have 

 solved the question, for in the matter of nomenclature as well as 

 in the study of the plants themselves, there is still considerable re- 

 search to be made, and I offer this only as a preliminary study with 

 a hope that it may bring to me more material for a longer and 

 fuller investigation. The rootstocks, in many cases, have shown 

 interesting features, but as that portion of the plant in Asclepias is 

 most difficult to collect, it is only in rare cases that satisfactory 

 specimens have come under my notice, and I have not been able 

 to examine enough of them to determine whether they possess 

 constant characters or not. 



The well-known and well-defined Asclepias Mexican a of the 

 West Coast is included in this study, as some of its narrow-leaved 

 forms have become confounded with what I take to be A. 

 alioidcs H.B.K. 



