THE GENUS Pholidota by Brian Milligan
Pholidota, together with other popular Asian genera such as Coelogyne, Pleione and Dendrochilum, is a member of the TRIBE Dendrobieae, SUBTRIBE Coelogyninae. The name is derived from the Greek pholidotos, which means scaly, in reference to the appearance of the floral buds. Some species in the genus are called rattlesnake orchids, because of the resemblance of their buds to the 'rattle' at the tip of the tail of the American rattlesnake. Pholidotas have pseudobulbs bearing mostly one or two leaves. The spiral inflorescences are usually arching or pendulous, and bear numerous small flowers arranged in two parallel rows.
There are over 50 species in the genus but only a few are common in cultivation. All are native to Asia, although Pholidota imbricata is also found in Australia. Pholidota pallida was mistakenly thought also to be native to Australia, but this is a rare species found only in India. Only five identified pholidota species seem to be grown in Victoria, namely, Pholidota articulata, P. chinensis, P. gibbosa and P. yunnanensis.
The most common of the above species is P. chinensis, which is found in Vietnam, Burma, Hong Kong and southern China, usually growing on damp rocks on river banks or on rainforest trees at altitudes 300-2500 m above sea level. Each pseudobulb usually carries two deep green leaves about 40 mm wide and 150 mm long. The pendulous inflorescences emerge from the apex of the new growths in spring and reach a length of 150-300 mm. Although the species is said to bear as many as 35 flowers, my plants seldom have more than a dozen, possibly because they are grown in a covered shade-house, rather than under intermediate conditions, as recommended for most pholidota species. The translucent flowers, measuring up to 20 mm across, have pale yellow-green sepals, off-white petals and a white labellum. I highly recommend this species, which grows vigorously and flowers reliably each November or December when grown without heat.
Pholidota imbricata, the type species for the genus Pholidota, is also frequently seen on our display benches, usually in January or February. Although native to Australia, it is also found in Papua New Guinea, Vietnam, Fiji and the Solomon Islands, where it grows at altitudes between sea level and 1600 m. The inflorescences reach 300 mm in length and bear up to 50 small (12.5 mm) flowers in two rows. The species epithet imbricata refers to the overlapping nature of the floral bracts, which vaguely resemble the tiles on a roof.
Pholidota articulata, a native of India, China, Vietnam, Burma, Thailand and Sulawesi, is also popular, and flowering plants regularly appear on our display bench between January and March. In nature it's found at altitudes of 300-1200 m, and it is variously described as cool- to hot-growing. The species epithet refers to the fact that each new growth arises from the apex of the previous year's growth, giving an articulated appearance, like a series of railway carriages. The musky flowers, each about 12.5 mm across, are translucent white or pale pink. The floral bracts tend to fall as the buds open.
Pholidota yunnanensis, as its name implies, is a native of southern China. The combined length of the pseudobulbs and leaves of this miniature species totals only 100 mm. The inflorescences emerge from the centre of the new growths in autumn, and bear about 15 tiny (5 mm) pinkish flowers in two parallel rows. My plant, which first flowered in May 2005, was the first to be displayed at the Orchid Species Society of Victoria. The only other pholidota species to be shown at that Society was Pholidota gibbosa (in 1985)!