Dendrobium lawesii

Selected Species - by Peter Taylor

Dendrobium lawesii

THE Reverend W. G. Lawes shares a place with a number of other men of the church (for example Rev. Parish who collected in Burma and after whom the beautiful Paphiopedilum parishii is named) in introducing desirable orchids to cultivation. Perhaps his most notable find was the spectacular Dendrobium lawesii, found in Papua New Guinea when Lawes worked for the London Missionary Society.

Left Dendrobium lawesii. A bicolour form obtained from Kevin Hipkins.

Plants were sent to Baron von Mueller who described it in the Melbourne Chemist in 1884 and named it after its discoverer (von Mueller was the Royal Botanist of Australia). Merle Reinikken in his A History of the Orchid mentions that von Mueller named more Australian plants than any other botanist and also states that von Mueller “denied himself the pleasures of matrimony partly from conscientious motives, but particularly in order to be free to give his time and his income to his favourite pursuits.”

Dendrobium lawesii is a medium sized epiphytic plant with pendulous growth habit, found in mist forests rather low on trunks and branches at an elevation of approximately 500 - 1800 metres. On well-grown, mature plants stem length can be up to 60cm: however, a number of years ago I noted plants grown by Darryl Smedley of Oceanic Orchids (which has a very interesting website related to Den. lawesii) with enormous stems growing in very small 50mm pots.

Flowers occur on leafless stems and are bell-shaped and waxy, generally in groups of six or more flowers. Flower colour is variable, from clear red and bicolour red/white and red/yellow through to the most wonderful orange that I saw on a plant belonging to the late Jack Janesse who had collected widely in Papua New Guinea.

In David Banks’ report on the St Ives Orchid Fair of 2007 (Australian Orchid Review Nov/Dec 2007) he shows a lovely pale mauve form grown by Gowan Stewart which won Champion Exotic Species. His accompanying text mentions that “it is reportedly pollinated by birds in the honeyeater family who mistake the blooms for tubular Rhododendron species ...“

Left: Dendrobium lawesii. This form of the plant won Champion Species Orchid of the Camden Haven Society Summer Show.

The two plants illustrated with this article are from my collection. The dark, glistening red flowered plant is of merit and won Champion Species at the Camden Haven Orchid Society Summer Show of 2008. The bicolour form is a division of a plant I got some time ago from Kevin Hipkins of Royale Orchids.

The mist forest habitat of the species indicates its cultural preferences. Intermediate temperatures (although my plants have experienced the low temperature of 5°C in winter with no appreciable set back) and filtered sunlight with good air movement are required. Andreé Millar in Orchids of Papua New Guinea (1999) maintains that “it is excellent for slab culture, either cork or wood”, but I had no success with slab culture. The best plants I have ever seen grown (Janesse , Smedley, Banks, Stewart) are grown in small pots, generally in sphagnum moss which provides the constant root moisture needed. I find that placing some granulated polystyrene pieces in the bottom quarter of the pot gives excellent drainage. My plants are kept constantly moist but many growers recommend a drier rest in winter which, it is claimed, results in better flowering.

Fertilising should be limited if growing in sphagnum moss - certainly organic fertilisers soon create a sour black slime on the surface of the moss. Generally quarter manufacturer’s recommended strength is suggested. My plants are grown in a shadehouse with two layers of 50% shade cloth in summer. In winter one layer of 50% shadecloth and a plastic ‘overcoat’ which fits over the house to provide protection from cool winds.

lawesii is a very adaptable orchid, relatively easy to grow and provides a wonderful splash of colour around Christmas time - hence the name given to it by the late Hermon Slade, the Christmas Bell Orchid.

Right: Showing the growth and flowering habit of Dendrobium lawesii.

Peter Taylor Port Macquarie, NSW