Gonolohus. ASCLEPIADACE^. 103 



§ 1. DicTYOLOBCs, Gray, I.e. Corolla reticulated and sometimes rugulose 

 with a fine network of colored veins ; the lobes commonly broad or roundish : 

 crown single. (The species mainly tropical and rather large-flowered.) 



G. reticulatus, Engelm. High-climbing, hirsute (especially the stems) with spreading 

 and reddish bristly hairs, minutely somewhat glandular ; leaves (1^ to 4 inches long) deeply 

 cordate with incurved auricles, acute or acuminate : peduncles equalling or exceeding the 

 slender petiole and sometimes longer than the leaf, 5-9-flowered, thrice the length of the 

 flower : corolla lurid green, with purplish venation, half inch in diameter, glabrous within, 

 somewhat hairy without ; the lobes broadly ovate or obovate : crown a narrow entire ring 

 around the base of the distinct column : stigma circular : follicles fusiform and long-acu- 

 minate, 3 to 5 inches long, strongly muricate. — Gray, 1. c. G. granulatas, Torr. Bot. Max. 

 Bound. 165, not Scheele. — Thickets and rocky banks, Texas to E. Arizona. (Monterey, 

 Mex.) 



§ 2. EuGONOLOBUs, Gray, I.e. Corolla not venulose-reticulated (at least not 

 conspicuously) ; the lobes from ovate-acuminate to linear : crown simple, un- 

 appendaged within, inserted at the junction of corolla and column or higher on 

 the latter : angles of the stigma little or not at all salient : stems herbaceou.-i, 

 usually freely twining. (Pubescence variable, especially the hirsute and spread- 

 ing or reflexed hairs, which often occur on the stems, petioles, and sometimes on 

 the leaves.) 



* Peduncles umbellately or sometimes more cymosely few-many-flowered: corolla rotate, 5- 

 parted ; the lobes stellately spreading or recurviug, 



•(— Thickish in texture, dull or dusky yellowish-green, sometimes turning lurid-purplish within, at 

 least toward the base ; the bud conical-acumiuate, at least the outside (a.^ well as calyx, pedicels, 

 and short peduncle) glabrous: crown a low and undulately 10-lobed fleshy disk at base of short 

 column under the stigma : anthers narrowly bordered at summit with a scarious membrane which 

 overlies the edge of the stigma: follicles unarmed, glabrous, 3-5-costate or angled, fleshy and 

 when mature and dry of spongy texture. 



G. SUberosus, R. Br. Leaves cordate with an open and shallow or sometimes deeper 

 and narrow sinus, acuminate, minutely pubescent, glabrate, or sometimes hairy (3 to 5 

 inches long) : umbels 3-9-flowered, much shorter than the petiole: corolla broadly conical 

 and with abrupt acumination, twisted in the bud ; its lobes ovate or becoming triangular- 

 lanceolate, acute, of thickish and firm texture, dusky, minutely whitish-pubescent inside, 

 but sometimes glabrate, hardly double the length lof the calyx-lobes. — Mem. Wem. Soc. 

 (name only) & Hort. Kew. ed. 2, ii. 82 (1811) ; Gr^y, Proc. 1. c, not Decaisne. Cynanchum 

 suberosum, L. Spec, as to Dill. Elth. i. 800, t. 229, f. 296. Vincetoxicuin gonocarpos, Walt. Car. 

 104, at least in part. Gonolohus macrophyllus, Chapm. Fl. i. 368, not Michx. — Virginia to 

 Florida, along and near the coast. 



•-G. Isevis, Michx. Usually less pubescent or hairy : leaves (in the typical form) oblong- 

 cordate with a deep and narrow but open sinus, conspicuously acuminate (3 to 6 inches 

 long) ; umbels 5-10-flowered, barely equalling the petiole : corolla rather elongated-conical 

 in the bud, not twisted; its lobes (3 to 5 lines long) narrowly or linear-lanceolate, obtuse, 

 glabrous inside, 3 or 4 times the length of the calyx. — Fl. ii. 119 ; Gray, Man. ed. 5, 399. 

 — Mississippi to Arkansas and E. Texas. Passes freely into 



^i^Var. macrophyllus. Leaves broadly cordate, and with the rounded basal lobes 

 approximate or even overlapping, abruptly acuminate, the larger often 9 or 10 inches long 

 and 7 or 8 broad, the under side commonly soft with a fine and short or sometimes granular- 

 glandular pubescence : calyx-lobes often ciliolate toward the apex. — G. macrophyllus, 

 Michx. 1. c. G. viridifloTus, Nutt. Gen. i. 163 ; therefore G. NiMallii, Becaisne in DC. Prodr. 

 viii. 598. G. tiliafolius, Decaisne, 1. c. 596. G. granulatus, Scheele in Linn. xxi. 7-59. TTnce- 

 toxicum gonocarpos, Walt. Car. 104, in part. — Virginia and Carolina to Texas, Kentucky and 

 Missouri. 



^— H— Corolla thinner in texture, mostly purple or whitish ; the lobes obtuse: crcmi cupulate, as 

 high as the anthers: membrane of thelatter inconspicuous or obsolete, or not inflected over ths 

 edge of the stigma: peduncle with the umbel or cymose cluster equalling or surpassing the 

 petiole : follicles ovate-lanceolate, terete, muricate : stems in all variably hirsute : calyx and out- 

 side of the corolla more or less pubescent or puberuleut. 



