668 CONVOLVULACEAE (CONVOLVULUS FAMILY) 



masses 5 pairs, horizontal. Follicles turgid, mostly muricate with soft warty 

 projections, sometimes ribbed. Seed with a coma. Herbs or shrubs with 

 opposite heart-shaped leaves and corymbose-umbeled greenish or dark purple 

 flowers on peduncles rising from between the petioles. Our species belong 

 to the typical section, with the crown simple and unappendaged, and the corolla 

 nearly veinless. (Name from vincere, to conquer, and toxicum, poison, applied 

 originally to species of the preceding genus in allusion to supposed curative 

 properties.) GONOLOBUS Michx., in part. 



* Crown a low undulately 10-lobed fleshy disk ; follicles unarmed, glabrous, 3-5- 



costate or -angled. 



1. V. suberbsum (L.) Britton. Leaves cordate with an open shallow or 

 sometimes deeper and narrow sinus, pointed, glabrate or hairy, 6-14 cm. long ; 

 umbels 3-9-flowered, much shorter than the petiole ; corolla broadly conical in 

 bud, abruptly pointed, twisted; lobes ovate or triangular-lanceolate, acute, pubes- 

 cent inside; calyx half as long. (Gonolobus R. Br.) Near the coast, Va. to 

 Fla. June-Aug. 



2. V. gonocarpos Walt. Leaves cordate with a deep and narrow often closed 

 sinus, conspicuously acuminate, 0.5-1.5 dm. long, finely pubescent beneath ; 

 umbels 5-10-flowered, barely equaling the petiole ; corolla elongated-conical in 

 bud, not twisted; lobes narrowly lanceolate, obtuse, glabrous inside, 3-4 times 

 as long as the calyx. (Gonolobus laevis Man. ed. 6, not Michx.) River-banks, 

 Va. to s. Ind., Mo., S. C., and Tex. June, July. 



* * Crown cup-shaped, as high as the anthers ; follicles muricate, not costate. 

 *- Crown fleshy, merely 10-crenate, or the crenatures bidentate. 



3. V. obliquum (Jacq.) Britton. Leaves rounded- to ovate-cordate with a 

 narrow sinus, abruptly acuminate, 0.7-2.5 dm. long; umbel many-flowered; 

 corolla in bud conical, its lobes linear-ligulate, 1-1.5 cm. long, 2 mm. wide, 

 crimson-purple inside, dull or greenish and minutely pubescent outside. (Gono- 

 lobus R. Br.) River-banks, Pa. and Va. to O. and Mo. June, July. 



4. V. hirsiitum (Michx.) Britton. Commonly more hairy ; leaves with the 

 basal lobes sometimes overlapping; peduncles fewer-flowered; corolla in bud 

 ovoid, its lobes elliptical-oblong, rarely 1 cm. long, barely puberulent outside, 

 brownish-purple to yellowish. (Gonolobus Michx.) Md. and Va. to Tenn. 

 and Fla. May-Aug. 



H- *- Crown thinner, the border lobed or toothed; leaves as in the preceding . 



5. V. Sh6rtii (Gray) Britton. Resembles no. 3, but larger-leaved ; corolla 

 conical in bud, dark crimson-purple, its lobes ligulate, 1.5 cm. long ; crown about 

 IQ-toothed, the alternate teeth thinner, narrower and longer, either emarginate 

 or 2-parted. (Gonolobus Gray.) Ky., and southw. 



6. V. carolinSnse (Jacq.) Britton. Flower-bud elongate-ovoid; corolla 

 brownish-purple, its lobes oblong or linear-oblong, rarely 1 cm. long ; crown 

 undulately and very obtusely 5-lobed, with a longer bifid subulate process in each 

 sinus. (Gonolobus R. Br.) Va. to Mo., and southw. May-July. 



7. V. Baldwinianum (Sweet) Britton. Corolla whitish, with spreading 

 oblong or spatulate lobes (at most 1 cm. long) ; crown deeply cleft into 5 usually 

 emarginate lobes half as long as the pair of subulate processes in each sinus. 

 (Gonolobus Sweet.) Ga. to Mo. and Ark. May, June. 



CONVOLVULACEAE (CONVOLVULUS FAMILY) 



Chiefly twining or trailing herbs, often with some milky juice, with alternate 

 leaves (or scales') and regular 6-androus flowers ; a calyx o/5 imbricated sepals ; 

 a 5-plaited or 5-lobed corolla convolute or twisted in the bud (imbricate in no. 6); 

 a 2(rarely ^-celled ovary (or in one tribe 2 separate pistils), with a pair of 

 erect ovules in each cell, the cells sometimes doubled by a false partition between 

 the seeds, so becoming 4-celled ; the embryo large, curved or coiled in mucilagi- 



