Cooktown Orchids, Butterfly Orchids
Epiphytes or lithophytes with very short, indiscernible rhizomes anchored by roots that arise from nodes at the base of the pseudobulb. The pseudobulbs are elongated, hard and cane-like, more or less cylindrical and leafy in the distal half to third. The leaves are relatively thin but fleshy, flat, without any channel or groove, much longer than wide, basally sheathing and with an entire apex. The flowers are borne on long racemes that arise from the upper nodes of a pseudobulb. Each flower, which is long-lasting, is relatively large and thin-textured. The perianth segments are flat, spread widely and the bases of the lateral sepals are fused with the column foot. The petals are much broader than the sepals. The labellum, which is distinctly three-lobed, has fringed or crested central ridges and a long basal spur. It is stiffly attached to the apex of the column foot.
Similar Genera
Significant Generic Characters
Epiphytic/lithophytic orchids; rhizomes short, indiscernible; roots from basal pseudobulb nodes; pseudobulbs elongated, hard, cane-like, more or less cylindrical, leafy in the distal half to third; leaves relatively thin but fleshy, flat, with an entire apex; racemes long, arising from distal nodes; flowers long-lasting, relatively large; perianth segments thin-textured, flat; lateral sepal bases fused with the column foot; petals much broader than the sepals; labellum stiffly attached to the apex of the column foot; lamina three-lobed, with a long basal spur; callus with fringed or crested central ridges; column foot with a deep central groove.
Size and Distribution
A genus of about 8 species distributed in Indonesia, East Timor, New Guinea and northern Australia where there are 4 endemic species. The Australian species occur in northern parts of the Northern Territory, the Kimberley region of northern Western Australia and in Queensland between Thursday Island in Torres Strait (9º25' S) and near Port Douglas (16º40' S). State occurrence: Queensland (including Thursday Island), Northern Territory, Western Australia.
Ecology
The Australian species of Vappodes occur in lowland and coastal areas growing on trees and rocks in moist or humid but airy often exposed sites. Habitats include vine thickets, open forest, woodland, coastal scrubs, swamp forest and mangroves. The climate is tropical and the majority of rain falls during the summer wet season (December to March), with the remaining months much drier and having sporadic or intermittent rain.
Biology
Pollination: The flowers of species of Vappodes last many days and are pollinated by large wasps and hornets. Some forms of Vappodes dicupha are self-pollinating.
Reproduction: Reproduction in Vappodes is solely from seed. Seed dispersal takes 4-6 months after pollination and the capsules develop in a pendulous position. Apomixis is unknown in the genus.
Seasonal Growth: The plants grow actively during the spring and summer months and are relatively quiescent for the remainder of the year.
Flowering: Flowering occurs in summer, autumn and winter.
Hybrids: Natural hybrids within native species of Vappodes are unknown but intergeneric natural hybrids occur (examples Durabaculum undulatum x Vappodes bigibba; Cepobaculum foelschei x Vappodes dicupha).
Derivation
Vappodes, which is derived from the Greek vappo, moth or butterfly and -odes, resemblance, refers to the large flowers that resemble moths or butterflies.
Botanical Description
Perennial, evergreen, epiphytic or lithophytic herbs, sympodial. Plants glabrous. Roots elongate, produced from nodes on the base of the pseudobulb. Rhizome superficial, branched. Pseudobulbs well-developed, crowded, elongate, basically cylindrical, hard, when young covered by scarious bracts. Trichomes absent. Aerial growths often present, arising from the apical nodes on the pseudobulbs. Leaves lasting 1-3 seasons, distichous, occurring on the distal half to third of the pseudobulb, sessile, longer than wide, flat, not grooved or channelled, thin but fleshy, smooth; base sheathing the pseudobulb; margins entire; apex entire. Inflorescence racemose, arcuate, arising from an apical node on a mature pseudobulb, multiflowered. Peduncle shorter or longer than the rhachis, the base covered with imbricate scarious bracts. Floral bracts scarious, sheathing the base of the pedicel. Pedicel relatively long, thin, merging with the ovary. Ovary short, straight, sometimes at right angles to the pedicel. Flowers resupinate, stalked, lasting many days, pink, mauve, purple or white; labellum with distinct striae. Perianth segments thin-textured, widely spreading, entire, straight, not twisted. Dorsal sepal free, subsimilar to the lateral sepals; apex entire, apiculate. Lateral sepals subsimilar to the dorsal sepal, attached by their bases to the column foot; apex apiculate. Petals free, much wider than the sepals; apex broadly obtuse, apiculate. Labellum stiffly attached to the apex of the column foot (see also spur below), markedly dissimilar in size and shape to the sepals and petals, calcarate. Labellum lamina more or less cuneate, strongly three-lobed; lateral lobes large, erect, flanking the column or incurved, entire; midlobe short or narrow, porrect to recurved; margins entire or undulate; apex entire. Callus consisting of narrow parallel ridges, usually fringed or crested on the midlobe. Nectar absent. Column lacking free filament and style, fleshy, shorter than the perianth segments, nearly straight. Column wings present, reduced, ventral and with short tooth-like apical stelidia. Column foot well developed, as long as or longer than the column, straight or curved, with a deep central groove. Spur present, formed by the fused elongated base of the labellum and apex of the column foot. Anther terminal, incumbent, 2-celled, persistent, attached dorsally by a ligulate claw, smooth, erostrate; apex papillate. Pollinarium absent. Pollinia 4 in 2 pairs, straight or falcate, yellow or orange, hard, waxy. Viscidium absent. Rostellum ventral, swollen, transverse. Stigma entire, transverse, concave. Capsules dehiscent, glabrous, pendulous; peduncle not elongated in fruit; pedicel not elongated in fruit. Seeds numerous, light coloured, winged.
Taxonomy
Vappodes, originally described as section Phalaenanthe within Dendrobium, was recently redescribed at generic rank (Jones and Clements 2002).
Nomenclature
Vappodes M.A.Clem. and D.L.Jones, Orchadian 13(11): 492 (2002).
Type species: Dendrobium bigibbum Lindl. [Vappodes bigibba (Lindl.) M.A.Clem. and D.L.Jones].
Dendrobium sect. Phalaenanthe Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1: 447 (1912).
References
Clements, M.A. and Jones, D.L. (2002). Nomenclatural changes in the Dendrobieae (Orchidaceae) 1: the Australasian region. Orchadian 13(11): 485-497.
Dockrill, A.W. (1969). Australian Indigenous Orchids. Volume 1. The Society for Growing Australian Plants, Halstead Press, Sydney.
Dockrill, A.W. (1992). Australian Indigenous Orchids. Volume 1 & 2. Surrey Beatty & Sons in association with The Society for Growing Australian Plants, Chipping Norton, NSW.
Schlechter, R. (1982). The Orchidaceae of German New Guinea (English translation by R.S. Rogers, H.J. Katz and J.T. Simmons). Australian Orchid Foundation, Melbourne.