Bryobium retusum, commonly known as Christmas Island urchin orchid,[1] is an epiphytic clump-forming orchid that has oval, fleshy green pseudobulbs, each with two leaves and between seven and twelve short-lived, self-pollinating, pale green, hairy flowers. This orchid is found between Java and New Caledonia.
Bryobium retusum is an epiphytic herb that forms small dense clumps with crowded, cylindrical pseudobulbs NaNmm long and NaNmm wide. Each pseudobulb has two linear to lance-shaped leaves NaNmm long and NaNmm wide. Between seven and twelve pale green flowers about 2.5mm long and wide are arranged on a flowering stem NaNmm long. The flowers are self-pollinating, short-lived and hairy on the outside. The sepal and petals are about 4mm long and 2mm wide, the petals slightly narrower than the sepals. The labellum is about 1mm long and wide with a small callus. Flowering occurs from September to November.[2]
Christmas Island urchin orchid was first formally described in 1825 by Carl Ludwig Blume who gave it the name Dendrolirium retusum and published the description in Bijdragen tot de flora van Nederlandsch Indië.[3] [4] In 2005 Yan Peng Ng and Phillip Cribb changed the name to Bryobium retusum.[5] The specific epithet (retusum) is a Latin word meaning "blunted", "rounded" or "notched at the apex".[6]
Bryobium retusum grows near the top of rainforest trees. It is found in Borneo, Java, the Lesser Sunda Islands, New Guinea, the Solomon Islands, New Caledonia and the Australian territory of Christmas Island.