RUBIACEAE  

Annual or perennial herbs or sometimes subshrubs, with subterete or quadrangular branches. Leaves opposite, sessile, usually linear, mostly 1-nerved; stipules with 2-several fimbriae or rarely reduced to a simple lobe. Flowers never heterostylous; in terminal corymbs or panicles, rarely solitary; bracts slender or filamentous. Calyx 4(5)-partite; segments ovate-triangular to subulate. Corolla 4(5)-lobed; lobes suberect or spreading, papillose above; cream, shades of brown, white or pinkish mauve; tube slender, cylindric below, slightly expanded towards mouth, with flattened, obtuse hairs within. Stamens included or only anther tips exserted; anthers sessile. Ovary 2-locular, with many ovules in each locule, attached to shield-like, shortly-stalked placentas attached below middle of central partition; style usually much shorter, but sometimes only slightly lower than anthers; stigma simple or bifid. Capsule bilocular, globose or ellipsoid, scarcely beaked. Seeds many, angular, somewhat alveolate. x = 9 (polyploidy).

Shrubs or small trees with both spines and brachyblasts present or 0. Leaves opposite, but may appear fascicled due to congestion, shortly petiolate, glabrous; domatia 0; stipules intrapetiolar, ovate, tightly inrolled and seldom persisting beyond apical node. Flowers borne in 1 axil near apex of lateral branches or brachyblasts, either solitary or up to 3 on a common peduncle, or peduncle almost obsolete; pedicels almost obsolete; bracts paired, ovate. Calyx with tube oblong-ovate, limb well developed, tubular, divided into triangular teeth near apex, inside pubescent, at least near apex and with colleters present near apex. Corolla 5(6)-lobed, white, often streaked with pink or red outside, usually salver-shaped; lobes elliptic to broadly elliptic, spreading, puberulous on both faces, contorted; tube narrowly cylindrical, slightly widened at apex, glabrous or pubescent outside, with a patch of hairs near midpoint inside. Stamens 5(6); anthers linear, sessile, attached near middle of corolla tube, partly exserted. Disc usually annular. Ovary 2-locular; ovules many; style narrowly cylindrical, glabrous, somewhat shorter than or +/- equalling corolla tube in length; stigma exserted or sometimes included, bifid, with 2 ovate lobes normally cohering. Fruit spherical to fusiform, thin-walled, unilocular; calyx limb persistent. Seeds many, embedded in fleshy placental tissue; testa thin, reticulate, often rugulose.

Shrubs or small trees. Leaves shortly petiolate; stipules +/- completely divided into 2 lobes, subpersistent or eventually falling. Flowers solitary or in lax, terminal, rather large, sweetly scented cymes. Calyx 4-6-lobed; lobes +/- leafy, ovate, to oblong, elliptic or lanceolate; tube turbinate or oblong. Corolla 4-6-lobed, white, with dense yellow hairs around narrow throat forming a star-shaped eye, hypocrateriform; lobes variable, usually finely puberulous, spreading; tube slender, adpressed hairy outside, densely hairy at throat. Stamens 4-6, situated in tube, included; filaments short; anthers linear. Disc small, swollen. Ovary 2-locular; ovules many; style slender, with 2 linear, thickened stigma arms just exserted in long-styled flowers, but only reaching to +/- halfway up tube in short-styled flowers. Fruit slightly fleshy but soon dry, indehiscent, oblong-ellipsoid to subglobose, crowned by persistent calyx lobes, many-seeded. Seeds adhering in 2 masses; strongly foveolate, pitted. x = 11 (polyploidy).

Shrubs or small trees, unarmed or lateral branches becoming stoutly spinescent; young parts often glutinous; branches sometimes in whorls of 3. Leaves opposite or verticillate, petiolate, thin to distinctly coriaceous; domatia 0 or present; stipules sheathing, ovate. Flowers subsessile or shortly pedicellate; solitary or rarely in corymbose heads; buds with wax-secreting glands. Calyx 5-8-lobed; tube cylindric to campanulate, sometimes split partly or completely to base on one side. Corolla 5-7-lobed, white, glabrous or hairy; lobes broadly ovate, obovate or elliptic, obtuse or rounded, contorted; tube cylindric, campanulate or funnel-shaped, hairy within. Stamens 5-8, arising in throat of corolla tube or lower, included or subexserted; anthers usually with apical appendage. Disc tumid, annular or crenate. Ovary 2-locular, with many parietal ovules, or 1-locular below and 6-locular above middle; style terete or linear, included or subexserted; stigma linear-lanceolate or clavate, sometimes with tumid ridges in hair-pin shape, sometimes 2-lobed. Fruit ovoid or globose, often comparatively large and hard, with a thick fibrous to woody wall, usually many-seeded. Seeds compressed, elliptic, smooth or with slightly reticulate testa, stuck together into a solid mass in pulp. x = 11.

Perennial herbs or annuals; stems erect, creeping or climbing, often distinctly 4-angled, glabrous, hairy or with recurved prickles. Leaves and stipules similar, in whorls of 4-10, (sub)sessile, blades linear, lanceolate to (ob)ovate, mostly with a prominent midvein (1-nerved). Flowers 4-merous, bisexual (and protandrous), rarely male and female, in axillary and/or terminal many- to few-flowered cymes. Calyx with lobes obsolete. Corolla mostly rotate, greenish (yellow), creamy white to bright yellow; lobes ovate to triangular, acute to acuminate. Stamens: anthers exserted. Ovary 2-locular, 1 ovule in each chamber, crowned by an often 2-lobed disc; style branches 2, joined below; stigmas capitate. Fruit dry, glabrous or variously hairy, dehiscing into (1)2 (sub)globose or reniform 1-seeded mericarps. Seeds round on dorsal side, +/- excavated on ventral side; 1 mericarp occasionally aborted. x = 11 (8, 10, 12) (aneuploids, high polyploidy).