VaIL: STUDIES IN THE ASCLEPIADACEAE 663 
— 1. Rouliniella unifaria (Scheele) 
Gonolobus unifarius Scheele, Linnaea, 21: 760. 1848. 
Roulinia unifaria Engelm. Mex. Bound. Surv. 160. 1850. 
A slender climbing and twining vine. Stems pale gray-green 
when fresh, striate, glabrous or minutely pubescent in lines on the 
upper portion and somewhat sulcate : leaves opposite, on petioles 
I—4 cm. long ; blades 3—7 cm. long, ovate, somewhat hastately cor- 
date, gradually acuminate, glabrous, thin, the auriculate basal 
lobes rounded, with a broad open sinus and a few glands at the 
base of the midvein above: peduncles longer than the petioles 
and as long as or exceeding the leaves: racemes as long or longer 
than the leaves, 7-12-flowered: rhachis minutely pubescent or 
puberulent in lines: flowers globose in bud: pedicels stout, I cm. 
long or less, pubescent : calyx-segments lanceolate-oblong, 4 mm. 
long, with a gland in each 
sinus : corolla 4~6 mm. long, 
white ; segments 3 mm. long, 
linear-oblong, 2.5 mm. wide, 
broadly obtuse or nearly trun- 
cate, thin, 3-veined, the callous 
thickened margins revolute ; 
crown attached to the base of 
the column, 5-parted to near 
the base ; segments erect, not 
exceeding the anthers, min- 
utely 3-lobed, the middle one Fic. I. 
slightly the longest, the lateral os 
lobes with thin infolded margins at the base within: anther- 
_ wings small ; anther-tips semi-orbicular, inflexed on the OS 
conic stigma: pollinia elliptical-ovoid ; caudicles broad at the 
attachment, orange-red on the upper margin ; corpuscle obtuse at 
the apex : follicles 6 cm. long, ovate, acuminate with an obtuse 
apex, coriaceous, glabrous: seeds 5 mm. long: coma I cm. long. 
(Fig. 1.) 
Type locality: On the Upper Guadeloupe River, near New 
_ Braunfels, Texas. Thickets, Kerr county, Texas, to “Mts. of 
_ Muerte,” New Mexico. Wright; western Texas to El Paso, 
Wright, 546; near Kerrville, Heller, 7899 (distributed as Am- 
pelanus ligulata) ; Mexican Boundary Survey, 70. 7059. : 
Bie. BES cited by Hemsley, for Roulinia unifaria from 
“North of Monclova, Coahuila,” Palmer, 829 are Roulintella Pat- 
