ASCLEPIADACEAE 951 



4. Metastelma barbigerum Scheele. Stems glabrous, slender, filiform above : leaf- 

 blades oblong or oblong-lanceolate, sometimes a few of them ovate-lanceolate, 2.5-5 cm. 

 long, acuminate and cuspidate, rounded at the base, thinnisb, glabrous except for a few 

 bail's on the midvein beneath and with a few glands above at the base of the blade, rarely 

 thicker and a little coriaceous : cymes 1-5-flowered : calyx -lobes ovate-lanceolate, 1-5 mm. 

 long, obtuse : corolla 4-5 mm. long, campanulate, dull greenish white ; lobes elongated, 

 linear-lanceolate, acute, the tips slightly revolute, densely and retrorsely white-bearded to 

 below the middle within : crown-lobes slender, linear-subulate, attached to the showy very 

 short column and appearing as if wing-angled towards its base, considerably exceeding the 

 anthers: anther-wings short, angled or rounded at the salient base: pollinia pear-shaped, 

 tapering upward to the broadish angled caudicle : the corpuscle obovate-oblong, obtuse at 

 the apex: follicles 4-5 cm. long, slender-fusiform, acuminate.: seeds 6 mm. long, pale 

 brown : coma 2.5 cm. long. 



In open woods and on rocky banks, Texas and New Mexico. 



5. Metastelma Baham^nse Griseb. Stems nearly glabrous, sometimes minutely 

 pubescent in lines: leaf-blades 1.5-2.5 cm. long : blades round-oval to oblong, mucronate- 

 cuspidate ; petioles slender, 5-7 mm. long : cymes 3-6-flowered, the pedicels 2-3 mm. 

 long, very slender, unequal : corolla white, open-campanulate, fleshy ; lobes obtuse, slightly 

 spreading, densely white-tomentose within : crown adnate to the whole of the high slender 

 column ; lobes linear-falcate, obtuse, not exceeding the anthers, wing-angled, internally 

 carinate : stigma flat or slightly depressed, obscurely 5-angled : follicles 5-6.5 cm. long, 

 fusiform, very slender, long-acuminate, glabrous, thickish, striate, dark purplish : seeds 5 

 mm. long, dark brown, slender, thin, with one or two rows of elevated tubercles along 

 the margin : coma about 2 cm. long. 



In sand, usually in open woods, Florida Keys. 



9. ROULINIELLA Vail. 

 Twining shrubby plants. Leaves opposite : blades cordate at the base, long-petioled. 

 Inflorescence cymose or somewhat paniculate or racemiform. Calyx small, glandulose. 

 Corolla rotate, with oblong, dextrorsely convolute lobes. Crown 5-lobed, attached at the 

 base of the corolla-tube and the gynostegium : lobes broad, often fleshy or leathery, the lat- 

 eral margins involute. Stigma flat and depressed, obscurely 5-rayed and 2-lobed. Follicles 

 thick, acute, smooth. Seeds comose. J[Roulinia Decne., not Brongn.] 



1. Rouliniella unifaria (Scheele) Vail. 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 : leaf-blades 3-7 cm. long, ovate, hastately cordate, gradually 

 acuminate, glabrous, thin, the auriculate basal lobes rounded, with an open sinus and a few 

 glands at the base of the blade above : calyx-lobes lanceolate-oblong, 4 mm. long, with a 

 gland in each sinus : corolla 4-6 mm. long, white ; lobes 3 mm. long, linear-oblong, 2.5 

 mm. wide, broadly obtuse or nearly truncate, thin, 3-veined, the revolute margins with 

 two thickened callous ridges at the revolute apex within : crown adnate to the base of the 

 column, 5-lobed to near the base ; lobes erect, obtuse, not exceeding the anthers, 3-lobed, 

 the middle lobe slightly the longest : anther-wings small ; anther-tips semi-orbicular, in- 

 flexed on the scarcely conic stigma : pollinia elliptical-ovoid, the caudicles broad at the 

 attachment, orange-red on the upper margin,' the corpuscle acute at the apex : follicles 6 

 cm. long, ovate, acuminate with an obtuse apex, coriaceous, glabrous : seeds 5 mm. long : 

 coma 1 cm. long. 



In thickets, southern Texas and New Mexico. Spring to fall. 



10. GONOLOBUS Michx. 

 Perennial twining herbaceous vines. Leaves opposite, cordate, thin. Flowers in 

 axillary peduncled cymes. Calyx-lobes 5, glandular within, lanceolate. Corolla white, 

 campanulate : lobes 5, slightly contorted, nearly erect. Crown nearly sessile, of 5 mem- 

 branous, erect truncate lobes, each appendaged by 2 terminal awns. Stamens inserted at 

 the base of the corolla : filaments united into a short tube : anthers tei'minated by an erect 

 or slightly inflexed membrane. Anther-wings corneous, salient at the base after the man- 

 ner of Asclepias. Pollinia oblong-elliptical on rather broad caudicles, pendulous. Stigma 

 conic, slightly 2-lobed. Follicles thick, strongly and sharply angled. Seeds comose. 



1. Gonolobus la^vis Michx. Stems high-climbing, slender, glabrous or minutely 

 pubescent in lines : leaves 4-15 cm. long ; blades ovate, gradually acuminate at the apex, 



