Dimorphorchis


Dimorphorchis is a genus of flowering plants from the orchid family, Orchidaceae. It contains 9 species, which are native to Papua New Guinea, the Philippines, Indonesia, Malaysia, Solomon Islands, and Brunei. It is remarkable for its two flower morphs present on the same plant.

Description

Vegetative characteristics

Its species are epiphytic, monopodial herbs with large, pendulous, spreading, or erect up to 200 cm long stems. The basal part of the stem bears roots. The distichously arranged, coriaceous, linear up to 70 cm long leaves have an unequally bilobed to acute apex.

Generative characteristics

The long, glabrous or pubescent, pendent or erect, racemose or paniculate, up to 3 metres long inflorescences bear dimorphic or not dimorphic, bisexual flowers. The 2-3 flowers closest to the base of the inflorescence are strongly fragrant, slightly smaller, and of a different colour compared to the rest of the flowers, which are unscented and have wavy petals. The four pollinia with an elliptic viscidium are grouped in two pairs. It is unknown how the genus is pollinated.

Taxonomy

It was published by Robert Allen Rolfe in 1919 with Dimorphorchis lowii Rolfe as the type species.

Species

It has nine species:

Phylogenetic relationships

Within the subtribe Aeridinae, it is the sistergroup to Thrixspermum.

Etymology

The generic name Dimorphorchis references the characteristic two flower morphs preset within the same plant.

Ecology

Habitat

It can grow as a lithophyte or epiphyte in rainforests.