Phaius – Swamp orchids.
Family Orchidaceae > Subfamily Epidendroideae > Tribe Collabieae.
The genus Phaius has 40 to 50 species of terrestrial orchids commonly known as Swamp or Nun’s-hood orchids.
Three or four species are found in N.E. Australia where they are listed as endangered.
Plants, which form clumps, can have pseudobulbs or elongated stems.
Inflorescence stalks arise in the bract axils.
Sepals and lateral petals are a similar shape, size and colour.
The base of the lip forms a small pouch or spur.
The lip has 3 variously coloured lobes.
The lateral lobes can curve upwards or outwards.
The edges of the middle lobe can be flat or wavy and the tip is a small point.
P. australis (Lesser Swamp orchid) has pseudobulbs, stems up to 2m high with 4 – 8 leaves up to 70 cm long.
Flowers are white externally and brown with yellow lines inside.
The lip is white with the inside having areas of pink, mauve and yellow.
P. australis var. australis, the Common Swamp orchid, has pseudobulbs.
The dark green pleated leaves are just over 1 m long and inflorescences up to 2 m long with up to 15 flowers.
Flowers are white externally and reddish-brown inside.
P. australis var. bernaysii (Yellow Swamp orchid) is white externally and yellow inside.
P. amboinensis (Arnhem Land Swamp orchid) is white all over with yellow on the lip.
The lip has a callus and long white hairs.
P. pictus (Forest Swamp orchid) is yellow externally and red with yellow stripes inside.
Phaius tankervilleae.
The Chinese Swamp orchid is easily cultivated and the most commonly seen species.
An evergreen orchid with up to 6 or 8 basal leaves whose bases sheath a pseudobulb.
Leaves can be over 1 m long and up to 25 cm wide and are pleated.
Erect basal inflorescences, 1 -2 m tall, can have over 30 large flowers.
Flowers are resupinate, 10 to 11 cm across, and have bracts up to 4 cm long.
The 3 spreading sepals are up to 55 mm long, white externally and purple-brown inside.
The 2 spreading lateral petals are coloured like the sepals.
The lip is about 5 cm long and has a small 6-8 mm spur.
The lateral lobes curve upward to form a tube partially covering the column.
The downward curving middle lobe has slightly ruffled edges.
The spur and base of the lip are a pale yellowish colour and the rest can be shades of pink, red and brown.
The flowers, which can self-pollinate without opening, have 1 anther.
The Malaysian Swamp orchid, P. wallichii, is similarly coloured.
J.F.
