Dendrobium

Dendrobium species are mostly epiphytic, or lithophytic although a few species are terrestrial. They are sympodial herbs with cylindrical roots usually arising from the base of a pseudobulb. The pseudobulbs, when present, are hard, sometimes cane-like, cylindrical or cone-shaped and more or less covered with the bases of the leaves. There are from one to many leaves arranged in two ranks, the leaves varying in shape from linear to oblong, sometimes cylindrical but never channelled or grooved. They are usually much longer than wide and last for only a single season.

Between one and a large number of resupinate or non-resupinate flowers are arranged along an unbranched flowering stem and may be short or long-lived. The flowers may be white, green, yellow, or pink to purple, often with contrasting colours in the labellum. The sepals and petals are usually free from and more or less similar to each other but markedly different from the labellum. The labellum is more or less egg-shaped, with the narrower end towards the base and flanks the column. There is often a callus consisting of narrow, parallel ridges, in the centre of the labellum.