Dendrobium speciosum subsp. hillii
Rock orchid, cane orchid
This extremely common epiphyte or lithophyte grows in rainforest and rainforest verges and moist areas of open forests around Brisbane. Plants commonly reach 3m across so this orchid is readily spotted and identified, even in the tops of rainforest trees.
The pseudobulbs grow to 1m by 40 mm and this orchid usually has copious aerial roots growing vertically. There are 2 to 5 rigid terminal leaves to 28 cm by 12 cm. The flower stem grows to 65 cm with up to 200 flowers.
Flowers are 5 cm across and white to pale yellow with purple markings on the labellum.
This distinctive orchid can be easily identified by its large robust pseudobulbs, large rigid leaves and long racemes crowded with small white to pale yellow flowers. The only other orchid which could be confused with this orchid is its natural hybrid Dendrobium x gracillimum which is a hybrid with Dendrobium gracilicaule which can be distinguished by its much thinner pseudobulbs and much smaller more rounded flowers.