Knoxia
Knoxia a small genus belongs to subfamily Rubioideae, tribe Knoxieae. The genus consists of nine species and distributed in the tropics from Africa through Northwest Australia (Mabberley, 2008). As the taxonomic account of Rubiaceae is now about to be published for Flora of Thailand in the year 2016-2019, it is necessary to revise some genera.
Duperrea is a monospecific genus and distributed in Myanmar, South-western China, Indo-China and Thailand. The genus belongs to tribe Pavettee, subfamily Ixoroideae
Annual or perennial herbs or undershrubs. Stem erect, subterete with axillary shoots, rarely unbranched or with basal rosette of leaves. Leaves opposite, petiolate or sessile; stipules interpetiolar, fimbriate. Inflorescences terminal or both terminal and axillary, thyrso-paniculate, lax and corymbose, variously congested or head-like. Flowers 4-merous, dimorphic, heterostylous. Calyx tube short hairy inside; lobes unequal, sometimes foliaceous. Corolla white, pale lilac or pink, lobes valvate in bud, spreading in open flowers, uncinate at apex, dimorphic, hypocrateriform to fundibular in short-styled form or tubular-campanulate with narrow tube and swollen mouth in long-styled form. Stamens 4, epipetalous, exserted in short-styled form and included in long-styled form; anthers dorsifixed, linear-obleng, attached to the middle of the corolla tube; filaments pubescent near attachment. Ovary 2-locular, each with a solitary ovule pendulous ovule from an apical placenta; style exserted or included; stigma bifid, equal. Fruit dry, dehiscent to tardily dehiscent into two indehiscent mericarps and supported by variously shaped carpophores. Seed ellipsoidal, dorsally compressed and keeled, ventrally concave.