Oncophyllum globuliforme (Nicholls) (previously named Bulbophyllum globuliforme), the Green Bead Orchid, or Miniature Moss-orchid. is an epiphytic orchid that occurs in subtropical rainforest in Queensland and New South Wales, Australia, in a variety of habitats including warm temperate rainforest, dry rainforest and wet sclerophyll forests at an altitude of 100–900 metres.
One of the smallest orchid species known, the tiny pseudobulbs are about the size of a pinhead and each has a tiny reduced thread-like leaf at the apex. It can form quite extensive mats on tree trunks. Flowering occurs mainly from October to November and May to August. Flowers are cream with yellow labellum, rarely flushed with red and cream labellum, and are carried on a solitary stem in the axils of stem bracts.
It grows on bark and forms a thick mat, on the trunk and larger branches of the Hoop Pine (Araucaria cunninghamii), and is often mistaken for moss or lichen.
A very similar species is the closely related Oncophyllum minutissimum or Red Bead Orchid. This related species possesses small hollow pseudobulbs that contain stomata (organs for gas exchange) on their inner surface. This minimizes the surface area and the danger of loss of water by transpiration.