Australian Tropical Rainforest Orchids
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Abaxianthus convexus

Piggyback Orchid

Abaxianthus convexus (Blume) M.A.Clem. & D.L.Jones, Orchadian 13(11): 485 (2002).

Desmotrichum convexum Blume, Bijdr. 1: 330 (1825); Dendrobium convexum (Blume) Lindl., Gen. sp. orchid. pl. 76 (1830); Callista convexa (Blume) Kuntze, Revis. gen. pl. 2: 654 (1891); Ephemerantha convexa (Blume) P.Hunt & Summerh., Taxon 10: 103 (1961); Flickingeria convexa (Blume) A.Hawkes, Orchid Weekly 2: 454 (1961). Type: Java, Mt. Salag, Apr., C. Blume s.n. (holo L).

Distribution

Occurs in north-eastern Queensland from Mount Finnigan to the ranges inland from Innisfail.

Altitude: 900-1600 m.

Description

Epiphytic herb forming creeping strands or large mats. Rhizome creeping, appressed to host, branched, 3 mm wide, brittle. Pseudobulbs widely-spaced, erect, obovoid, 4-5 cm x 0.8-1 cm, yellowish green, shiny, hard, on short stem 1 cm long. Leaf solitary on pseudobulb, erect, apical, shortly petiolate, base not sheathing pseudobulb; lamina ovate, 5-8 cm x 1.5-1.8 cm, dark green, leathery, margins entire, apex unequally emarginate. Inflorescence single-flowered, pseudo-axillary, arising from meristem at apex of pseuodobulb; pedicels 5 mm long. Flowers 1-2, non-resupinate, porrect, 12-15 mm wide, cream with a red and yellow labellum, lasting 8-10 hours. Sepals and petals widely spreading. Dorsal sepal free, broadly triangular, 5-6 mm x 4 mm, apex subacute. Lateral sepals broadly triangular, 3-4 mm x 4 mm, inner margins partially fused, bases fused to column foot. Petals free, linear, 5-6 mm x 1 mm, apex acute. Labellum 11 mm x 4 mm, more or less oblong, relatively thick-textured, curved in the middle where red, strongly 3-lobed; lateral lobes, erect, obtuse; midlobe yellow, with 3 prominent ridges, apex with two large apical lobes. Spur absent. Column nearly straight, 5 mm x 3 mm. Column foot 7 mm long, shallowly curved. Pollinia 4 in 2 pairs, straight or slightly falcate, yellow or orange, hard, waxy. Capsules pendulous, dehiscent.

Ecology

Occurs mainly on mangroves, in swamps and around the mouths of large rivers and estuaries. It grows in a hot and humid tropical climate, with the majority of rain falling during the summer wet season (December to March) and the remaining months being much drier with sporadic rainfall. The flowers are insect pollinated but the vector is unknown. Each flower lasts for 8-10 hours.

Highly localised.

Flowering period: Sporadic throughout the year.

Name Changes

Until recently known as Flickingeria convexa.

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