Pentaphragma longisepalum is a species of flowering plant in the family Pentaphragmataceae. It has elliptical leaves, capitate inflorescences, and whitish flowers. The species is native to Borneo, and was described in 1990.
Taxonomy The species was described by Ruth Kiew in 1990. It was previously confused with Pentaphragma cyrtandriforme.
Distribution Pentaphragma longisepalum is native to the wet tropical biome of Sabah and Sarawak, Borneo. The species is found in montane forests, at elevations of .
It grows in shady areas on ridges and wet cliffs, and near streams.
Description Pentaphragma longisepalum grows high, and flowers when around high. The stem is thick, and woody at the base.
The leaves are elliptical, long, wide, and papery when dry. The leaf stems are long.
The inflorescence is capitate, and has three to ten flowers, which are arranged in two rows. The inflorescence stem is long. The flowers are long, wide, have five parts, and lack stems. The calyx has whitish, membranous, lanceolate lobes. The corolla is gamopetalous, and has a short, fleshy tube, which is around long. The corolla lobes are white to whitish-green, and turn cream to yellow. The lobes are membranous, around long, and around wide. The hypanthium is ellipsoid, long, wide, and enlarges when the plant is in fruit.
References