424 Vail : Studies in the Asclepiadaceae 



Asclcpias pcrennis var. parvitla (A. Gray) Proc. Am. Acad. 12 : 

 70. 1876. 



Asclcpias uivca Hemsl. Biol. Centr. Am. 2: 325 and 4 : 69. 

 1 88 1-2. Not Linn. 1753. 



Pale gray-green throughout. Stem woody at the base, 3 dm. 

 high, or more, erect, pubescent, often branched above : leav^es 

 short-petioled ; blades lanceolate or oblong-lanceolate, tapering at 

 each end, 4-6 cm. long, rather thick and coriaceous, glabrous or 

 minutely puberulent above, puberulent beneath on the veins and 

 revolute margins : peduncles 3-9, terminal and lateral, 1-4 cm. 

 long; umbels io-20-flo\vere'd : corolla white, small; column 

 slender ; hoods hastately sagittate at the base, not exceeding the 

 anthers ; horn falcate, thin, exserted, inflexed over the anthers : 

 anther-wings narrow, entire at the salient base : follicles slender- 

 fusiform, tapering to each end, 7-9 cm. long, glabrous : seeds 7 

 mm. long, red-brown, very thin, glabrous ; coma 2-3 cm. long, 

 abundant. 



Mexican Boundary Survey, Head of Rock Creek, Bigelow, 

 July 7, 1852; '' Nczu Mexico,'' Wright; Texas: Havard, Neally ; 

 Mexico: Palmer, no. 812. 



The Wright specimen [no. 1684 in part] enumerated here is 

 in the Herbarium of Columbia University. No. 1683, also of 

 Wright's collection, contains besides A. parvula some specimens 

 of A. longicornu Benth. (the plant since described as Podostemma 

 Emoryi Greene, Pitt. 3 : 237), and some specimens of A. scaposa 



Vail. 



Stelmagonum ? Holtonii 



A low perennial herb. Root slender, vertical : stems slender, 

 twining above, granular-puberulent and thinly hirsute with s.tiff 

 spreading hairs, the lower portion with small corky-barked ridges : 

 leaves opposite, on slender, granulose-puberulent and hirsute, 

 1.5-2.5 cm. long petioles ; blades ovate-cordate, 3-4 cm. long, 

 1.5-2 cm. wide, acuminate at the apex, basal lobes rounded with 

 narrow open sinus, granular-puberulent and with a few scat- 

 tered short stiff hairs above, granular-puberulent and with 

 more numerous stiff hairs beneath, especially on the veins, mar- 

 gins ciliate : flowers 4-7 in short-peduncled bracteolate cymes : 

 peduncles axillary, 3 cm. long ; pedicels 4-5 mm. long, the brac- 

 teoles subulate, very small, persistent : calyx 5-parted to below 

 the middle, 2-3 mm. long, granular-puberulent and ciliate ; 

 segments acuminate, with an erect subulate gland in each sinus : 

 corolla campanulate, j-^ mm. long ? or more, 5-parted to a 



