956 ASCLEPIADACEAE 



column and is free at tlie short canaliculate obtuse apex : anther-tips membranous, incurved 

 over the anthers : pollinia oblong, truncate at the attachment of the caudicle : follicles 9 

 cm. long, 3 cm. broad, narrowly oval, tapering each way, thick and coriaceous, pubescent, 

 short-muricate : seeds 10 mm. long, thick and coriaceous, red-brown, crenate at the apex : 

 coma 3.5 cm. long, rather coarse. 



On dry prairies, Arkansas and Texas. Spring and summer. 



13. Vincetoxicum pubiflorum (Decne. ) Vail. Stems from a slender perennial root- 

 stock, branched at the base, the branches spreading or procumbent and diffuse, 2-4 dm. long, 

 clothed with a short glandular pubescence and longer spreading hairs : leaf-blades broadly 

 cordate or reniform, 2-4 cm. long, acutish or apiculate or some of them acuminate, the 

 basal lobes rounded : peduncles none or merely a terminal one by the reduction of the upper 

 leaves to bracts : pedicels 2 or 3 in a fascicle : calyx-lobes acute, very small : corolla cam- 

 panulate ; lobes about as long as the tube, oblong-ovate, 4-5 mm long, dull purplish, 

 acutish, minutely hirsute on both surfaces, reticulated within : crown shallow cup-shaped, 

 with 10 rounded undulations, each alternate one with an adnate fleshy acute beak or horn 

 terminating the adnate crest or rib within, with minute auricles at the base : stigmatic 

 disk acutely angled : follicles 4 cm. long, ovate, muricate, much wrinkled : seeds 4 mm. 

 long : mature fruit not seen. 



In dry grounds or thickets, Georgia and Florida. Summer and fall. 



14. Vincetoxicum productum (Torr. ) Vail. Stems minutely pubescent, low and 

 twining, 4 dm. long or more : leaf-blades sagittate, cordate, 3-4.5 cm. long, tapering to a 

 long-acuminate apex, the basal lobes round, shorter than the (7-10 cm. long) petioles : 

 peduncles axillary, as long as the petioles, 3-4-flowered : calyx-lobes with a small gland a 

 little below each sinus : corolla narrowly-campanulate, dull greenish purple, puberulous 

 outside, nearly glabrous within ; lobes about as long as the tube, linear or oblong, nearly 

 erect : crown nearly equalling the anthers and stigma, entire or barely undulate, thin, in- 

 serted at the base of the short column and connected with it by 5 adnate crests whicli are 

 free at the 2-toothed or entire apex and canaliculate on the inner side : anther-wings 

 small, nearly acute : stigma obtusely 5-angled : pollinia ol^liquely ovoid, on broad-winged 

 caudicles : follicles ovate, 3 cm. long or more, minutely puberulous : follicles smooth. 



On plains, Texas to Arizona and adjacent Mexico. Summer and fall. 



15. Vincetoxicum parviflorum (Torr.) V^ail. Stems villous-hirsute, decumbent, 

 diffuse, 1-2 dm. or 3 dm. long, branched, fascicled on a slender vertical perennial rootstock : 

 leaf-blades ovate or orbicular-cordate, obtuse or acutish, 1-3 cm. long : peduncles 6-10 cm. 

 long, slender, terminal and lateral, somewhat racemosely several-flowered : flowers short- 

 pedicelled : calyx-lobes lanceolate-elliptical : corolla rotate ; lobes much longer than the 

 tube, oblong, obtuse, 2.5 mm. long, thick and fleshy with a whitish scarious margin, 

 papillose within : crown of 5 separate bidentate erect whitish fleshy lobes, which exceed the 

 anthers, each with an erect, slightly incurved, linear, flat, obtuse or acutish process, aris- 

 ing from near the base of tlie segment and commonly surpassing it : stigmatic disk flat or 

 slightly depressed : pollinia obliquely ovoid-obovate ; caudicles broad with 1 or 2 wing- 

 like appendages : follicles 3-4 cm. long, or more, ovate, tapering and obtuse at the apex, 

 obtuse at the base, pubescent, tuberculate and coarsely muricate : seeds 5 mm. long, round- 

 oblong, crenate at the apex, thin : coma 1 cm. long. 



In rocky soil, southern Texas. Summer. 



16. Vincetoxicum brevicoronatum (Robinson) Vail. Stems villous-hirsute, 

 diffuse, ascending, 1-3 dm. long : leaf-blades sessile or short-petioled, ovate or ovate- 

 orbicular, 1-2.5 cm. long, 1-1.5 cm. wide, cordate at the base, acute or acuminate at the 

 apex, glabrous or puberulent above, wrinkled or undulate on the margins, villous-hirsute 

 and the midrib and veins whitish beneath : flowers short-pedicelled, 3-8 at the apex of the 

 slender 2-7 cm. long axillary peduncle, minutely Ijracteolate : calyx-lobes oblong-lanceo- 

 late, acutish : corolla 2-3 mm. long, dark dull purplish ; lobes erect, rather thick and 

 flesliy, narrowly lanceolate, with white margins : crown of 5 short, thick, whitish rather 

 fleshy truncate lobes not exceeding the stigma, each with an erect slender once or twice 

 longer internal horn or process : anther wings very small, corneous : stigma a little de- 

 pressed : pollinia subglobose : corpuscle linear-oblong, nearly as long as the pollinia : fol- 

 licles about 4 cm. long, coarsely muricate : seeds not seen. 



On saudy plains, Texas. Summer. 



Order 7. POLEMONIALES. 



Herbs, or sometimes shrubs or trees, the plants of some families parasitic. 

 Leaves with dilated blades, or scale-like. Flowers mainly perfect, variously 



