[Reprinted from the Bulletin of the Torkev Potanical L'li b, a6 : Aug., i8<^.] 



Studies in the Asclepiadaceae.— IV 



]iV Anna Mikkay Vail 



I. NOTES ON SOME OLD TYPES, WITH DESCRIPTIONS OF NEW OR LITTLE KNOWN SPECIES 



AscLEi'iAs scAPOSA Vail, Bull. Torr. l^ot. Club, 25 : 171. 1898 

 On a specimen of this species in Wright's New Mexican col- 

 lection, no. 1683 in part, preserved in the Herbarium of the British 

 Museum, I was fortunate to find a somewhat mature but complete 

 flower, which through the courtesy of Mr. James Britten I was 

 permitted to examine closely, so that to my former description I 

 am able to add the following : 



Corolla-segments 5 mm. long, apparently white ; column short 

 and broad ; hoods of the corona barely exceeding the anthers, 

 2-2.5 "'"''^- ^"''gJi' ^^'liite or whitish, slightly pendulous or saccate 

 at base, 5 -dentate at the apex ; central tooth rounded, the inter- 

 mediate teeth acutish, the two ventral ones infolded, erect, slender, 

 attenuated, nearly twice as long ; horn arising from about the middle 

 of the hood, slender, exserted ; anther-wings salient and somewhat 

 rounded at the base, apparently entire. 



In floral structure allied to A. qidnqiicdcntata Gray and to A. 

 Palmcri Vail, but its low habit and solitary terminal peduncle are, 

 with few exceptions, rather unusual in the genus. I have seen 

 only four specimens of it, the one in the Herbarium of Columbia 

 University (Wright, no. 1684 in part), a fragment in Herb. Gray 

 from the same collection (no. 1683 in part), the specimen men- 

 tioned above, and the one referred to below. In the first three 

 cases it has been distributed with A. longicormi Benth. and A. 

 parviflora Willd. {A. pcrcnnis parinda Gray). The fourth speci- 

 men is in the Herbarium of the Missouri Botanic Garden and is on 

 a sheet with a specimen of (probably) A. longicornu Benth. in fruit 

 only, the label bearing the following inscription : " No. 7, Ascl. 

 longiconiu, Wright, 185 i." 



Asclepias parvula (A. Gray) 



Asdepias parvifolia Willd.? Torr. Mex. Bound. Surv. 164. 

 1859. Not Ait. 1789. 



(423) 



