Lianas or scandent shrubs, climbing by circinate tendrils, the tendrils originating from axils of leaves, especially those subtending inflorescences, terminating axillary branches, or axillary from cyme bracts, plants unarmed, bud scales present. Leaves alternate, petiolate, venation pinnate, lateral veins without stripes, glands at junction of leaf blade and petiole frequently stipitate or foliaceous, margin dentate, each tooth with an apical gland; stipules free, borne laterally at base of petiole, un-lobed or more frequently 2- (or rarely 3-) lobed. Inflorescences axillary or terminal, racemiform or paniculate thyrses composed of small, multi-flowered cymes, the cymes subtended by bracts, peduncles of cymes usually very short, pedicels elongating as flowers mature. Flowers bisexual (in our area; reportedly elsewhere sometimes unisexual by abortion, the plants polygamous), 5-merous. Hypanthium shallow obconical to campanulate, adhering to the ovary. Sepals triangular, adaxially keeled, persistent. Petals usually smaller or equal to sepals in length, strongly concave, short-clawed, limb apically rounded to 2-fid, white or greenish-white, enfolding the stamens at anthesis. Stamens opposite petals, slightly shorter to slightly longer than petals at maturity. . Disk broadly annular nearly filling mouth of hypanthium excluding small central annulus, epigynous, fleshy, nectiferous, glabrous, pubescent, or trichomes restricted to rim of annulus, margin with 5 chartaceous lobes opposite the sepals (rarely un-lobed), the lobes entire or apically 2- or irregularly- lobed. Ovary inferior, 3-locular, style 3-fid, the style exerted through disc annulus, usually after stamen dehiscence, stigmas 3, small. Fruit a dry schizocarp, 3-winged at maturity, separating septicidally into three 2-winged mericarps each of which remains temporarily apically attached and suspended from 2 carpophores. Mericarps indehiscent, 1-seeded. Aprox. 50 species, pantropical with majority of species in the New World from Southern Florida to South America, the South American species in need of modern revision.
The shape of the mericarps is very helpful in distinguishing the species of Gouania. The dumbbell-shape mericarps are transversely oblong with a very broad sinus at the apex and base of the fruit body. The fruit body itself is like the narrow bar or handhold of the dumbbell. Bornstein (1989: 165) described this fruit shape as “Fruit wing attached to side of fruit body only,” and I borrow his description. It’s not technically true as a thin margin of the wing continues along the apex and base of the fruit body, but it does help to explain the shape. The other shape I term the butterfly. The butterfly-shape mericarps are more or less circular to transversely oblong with emarginations to deep clefts at the apex and base of the fruit body, or only at the base in G. velutina. Bornstein (1989:165) described this type as “Fruit wing attached to side and base, and/or apex of fruit body” and I borrow again from him. To help define the shape of mericarps, the following measurements were made: height of fruit body, height of mericarp wings, distance between highest points of two wings, width of mericarp, and width of fruit body.
Un grupo tropical y subtropical con quizás 50 especies; 4 especies se encuentran en Nicaragua and 1 expected. Modified AP 18 Aug 2013