1	Terminal leaflet much longer than broad, lateral veins 10-15 on each side of midvein; upper 2 lobes of calyx connate; articles 2-4, pubescent.		1 C. campanulata
+	Terminal leaflet much broader than long, lateral veins 2-5 on each side of midvein; upper 2 lobes of calyx free or slightly connate; articles 4 or 5, glabrous (only C. hainanensis with 2 or 3 articles, extremely shortly uncinate pubescent)		(2)
2 (1)	Upper 2 lobes of calyx free, tube 3-4 × as long as lobes, calyx not half-hyaline, with dense uncinate hairs, small verrucae, and obscure reticulate veins; terminal leaflet obovate-rhombic, sometimes nearly square; subshrubs.		2 C. constricta
+	Upper 2 lobes of calyx slightly connate, lower lobes ca. as long as tube, calyx dry-membranous, half-hyaline, obviously reticulate veined; herbs		(3)
3 (2)	Terminal leaflet mostly rhombic or narrowly rhombic, 4-6 × broader than long.		3 C. vespertilionis
+	Terminal leaflet mostly reniform, orbicular-triangular, obovate, or nearly obtriangular, less than 3 × broader than long		(4)
4 (3)	Terminal leaflet mostly reniform, orbicular-triangular, or obovate, 5-15 × 10-20 mm; articles 4 or 5, glabrous.		4 C. obcordata
+	Terminal leaflet nearly obtriangular, 20-30 × 15-25 mm; articles 2 or 3, shortly uncinate pubescent.		5 C. hainanensis