Family: Orchidaceae

This very large genus of 1000 to 1200 orchids is distributed widely, mostly in the tropics. Many species are found in New Guinea. It is possible to select only a few species here to give a general idea of the genus. This plant usually has a conspicuous pseudobulb and a single leaf, sometimes two, growing from the top of the pseudobulb, but in some cases it has a long rhizome which bears a number of well-spaced pseudobulbs. These are hard to contain in a pot so may be better grown in a basket. The leaves vary greatly in size between the species.

Species

B. globuliforme is probably one of the smallest orchids of any type, with pseudobulbs about 2 mm (1/12 in) in diameter; the leaf is 1.5 mm (1/16 in) long and the flower parts vary from 1 to 3 mm (1/25-1/8 in). Native to Australia's northern New South Wales and southern Queensland, this plant is rarely seen because it grows on the upper branches of the hoop pine, Araucaria cunninghamii.

B. lobbii is an exceptional orchid from Indonesia, Borneo and Malaysia. This species is difficult to plant in a pot as the pseudobulbs appear at up to 8 cm (3 in) intervals along the rhizome. However the roots of the new pseudobulbs will adhere to the outside of the pot. The rhizome can actually be trained across a number of pots. The leaves of this plant can reach 25 cm (10 in) in length and 7 cm (23/4 in) in width. The single, erect, yellow-brown inflorescence measuring 7-10 cm (2 3/4-4 in) across, is produced from any node on the rhizome. It flowers in summer. Although it grows in the wild at an altitude of 1200 m (40 000 ft), it needs to be housed under glass outside the subtropics.

B. longiflorum occurs naturally in Southeast Asia and Papua New Guinea and in Cape York in northern Australia. The pseudobulb is 2-3 cm (1 in) high and produces a single leaf to 15 cm (6 in) long. The erect raceme of six or seven flowers, arranged in a half-circle, arises from the base of the pseudobulb. The greenish cream flowers, with purple dots or blotches, are spectacular. This species does reasonably well outdoors in frost-free areas but may need extra warmth to flower. In areas which experience frost, it will need to be grown under shelter.

Cultivation

Grow bulbophyllums in a cool to intermediate greenhouse or conservatory. They are best grown in orchid baskets or shallow, hanging pots, in special compost formulated for epiphytic orchids, which includes coarse bark and charcoal. You should be able to buy this from an orchid nursery. Alternatively, plants can be mounted on slabs of bark which can then be hung up in the greenhouse. During the summer, plants need high humidity and shade from direct sun. Water normally and freely at this time but do not water in winter, when the compost must be dry. Mist spray the plants with tepid water several times a day in summer. No shading is needed in winter. New pseudobulbs can be encouraged to grow by placing a layer of sphagnum moss on top of the compost or on the surface of the bark slab. These orchids grow fairly slowly but this is not an excuse for excessive feeding. Apply a very weak liquid fertilizer solution every week or two during the growing season.

Climate

Grown outdoors only in tropical and subtropical climates.