Thepparatia thailandica Phuph.
Malvaceae Info (Home)
Thepparatia Phuph. is a recently described (2006) monotypic genus, currently only known from a collection from dry evergreen forest in Tak province in northwestern Thailand. The genus is named to honour the Thai royal Her Royal Highness Princess Maha Chakri Sirindhorn. (Thepparat is her royal title.)
This genus is described as related to Thespesia but differing in being a woody climber, in lacking foliar (and epicalyx) nectaries, in possessing articulate pedicels, and in having a inflorescence composed of a terminal raceme of more than 10 flowers.
The single known spcies is Thepparatia thailandica Phuph. This is a woody climber with stems up to 20m long. The leaves are spirally arranged, and crowded towards the ends of the branches. They are broadly ovate, 7-12×8-12cm in size, chartaceous, shallowly to moderately 3-lobed, with a cordate base, acuminate apex, and an irregular crenate-serrate margin. Glands are present on the upper surface, and also on the midrib and other veins. The upper surface is glabrous; the lower surface minutely stellate-pubescent with some large stellate hairs. The petioles are 5-10cm long, with a minutely stellate-puberulous indumentum. The stipules are caducous, filiform, and 4-6mm long.
The flowers are borne in drooping racemose inflorescences situated at the end of branches. These are up to 20 cm long, with a stellate-tomentose indumentum. The flowers are pedicellate, the pedicels being 1.5-1.8 cm long, with an articulation about 0.5 cm below the epicalyx. The persisent epicalyx is composed of 5-7 oblong to elliptic bracteoles, 7-10×3-5mm in dimension, which are reddish-green in colour, fused at the base, and stellate-tomentose on both surfaces. The calyx is 10-14mm long. It is composed of 5 green sepals, which are fused for about half their length. The free portions are ovate, 5-8×4-5mm in size, with an acute apex, a medial nerve, and a stellate-tomentose indumentum on both surfaces. The corolla is described as yellow, with a large dark-red centre. (Photographs show the outermost parts of the petals as near-white, but this might be due saturation of the images.) It is campanulate. The petals number 5. They measure 3-3.5×1.5-2cm in size, and are adnate to the base of the staminal tube, and obovate. The apex is reflexed. The outside surface is stellate-puberulous, with longitudinal lines; the inside surface glabrous.
The staminal column is 1.5-2cm long, with an unequally 5-toohed apex, and is densely antheriferous throughout its length. The filaments are about 1mm long, frequently occurring in pairs. The anthers are yellow and horseshoe-shaped. The pollen is echinate.
The ovary is ovoid, densely pubescent, and composed of 5 cells, each containing 12 ovules. The pistil is described as being shorter than the staminal column, with and undivided style, and with a small, non-sulcate, stigma, constrasting with the state in Thespesia, where the pistil is longer than the staminal column, with a clavate, 5-sulcate, papilose, stigma. However I prefer a different interpretation - that the flowers are protandrous (i.e. that the stamens mature before the pistil), as in many malvaceous plants, and that the mature pistil exceeds the length of staminal column. Under this interpretation the nature of the mature stigma is unknown. (It is possible instead that the staminal column is shed to expose the pistil, but this doesn't seem consistent with the adnation of petals and staminal column.)
The fruits have not been described.
Malvaceae Info (Home)
© 2007 Stewart R. Hinsley