Christmas orchid Calanthe australasica

Ian Hutton, The Lord Howe Island Signal

This month’s orchid is aptly named the Christmas orchid because its flowers are often out around Christmas, although some flowers may be evident anywhere between October and February, and occasionally even as early as May. The genus name Calanthe means ‘beautiful flower’ in Greek, an allusion to the attractive flowers typical of many species within the genus.

Calanthe australasica is a tall evergreen herbaceous plant, with a rosette of four to nine dark green leaves, lance-shaped and 20 to 60 cm long, 6 to 15 cm wide, with strong parallel veins. Once each year the plants produce a flower stalk which may be 50 to 100cm long containing 18 to 40 large white flowers crowded near the top. The flowers at the base of the flower stalk open first, then those higher up gradually open so that each plant produces flowers for many weeks. The Christmas orchid has the largest flower of any of the Lord Howe orchids.

Calanthe orchids produce nectar which is collected by bees, butterflies and wasps. Not much is known about the pollinators of the Christmas Orchid although it is thought that moths might pollinate it because it grows mostly in shady spots on the forest floor – not the best place for bees or butterflies! If the flowers are pollinated, a shiny green seed pod develops, which hangs down and measures about 4cm.

This plant is quite common along a section of the Boat Harbour track in shaded forest, and numbers appear to be increasing following removal of rodents in 2019/20. It is also widely distributed along the east coast of Australia, occurring from Iron Range in far north-eastern Queensland to Termeil on the south coast of New South Wales.

(This orchid was previously confused with Calanthe triplicata which is distributed widely through Asia, China, Indian and Pacific Ocean islands). 

This article appeared in The Lord Howe Island Signal, 31 December 2023.