It is commonly found growing in rainforest in the North, South, Stewart and Chatham Islands and normally flowers in summer and early autumn.

Dendrobium cunninghamii is an epiphytic or lithophytic orchid herb that forms tufts up 2.0 m (7 ft) wide with wiry, cane-like stems up to 1.0 m (3 ft) long and 7 mm (0.3 in) in diameter.

The petals and sepals are white but some parts of the labellum are rose pink, purplish and green.

[2][3] Dendrobium cunninghamii was first formally discovered in 1835 by John Lindley and the description was published in Edwards's Botanical Register.

It sometimes grows on rocks and cliff faces, even on brick or concrete walls.