Hetaeria oblongifolia

Hairy Jewel Orchids

Deciduous terrestrials with succulent, above-ground, creeping rhizomes with an erect apex, anchored by wiry roots that appear woolly.  The relatively narrow dark green leaves, which arise in a central rosette, are thin-textured and stalked. Spikes short to long, terminal on a shoot, usually hairy. Flowers small, upside-down, dull-coloured, hairy. Perianth segments free. Lateral sepals sometimes hooding the labellum base. Labellum attached to the anterior base of the column, with a shallow pouched base and concave blade. Basal pouch with 2 groups of small irregular glands.

Similar Genera

Zeuxine

Significant Generic Characters

Terrestrial orchids, deciduous; rhizome and stems succulent, above-ground, creeping at the base with an erect apex, anchored by wiry nodal roots that appear woolly; leaves petiolate, in a central rosette, glabrous, relatively narrow, thin-textured, usually asymmetric; inflorescence spicate, terminal on a shoot; flowers non-resupinate, small, often short-lived, dull-coloured (greenish, whitish or yellowish), externally glabrous or hairy; sepals and petals free. Labellum attached to the anterior base of the column, obscurely lobed, with a shallow saccate base containing 2 groups of small irregular calli; hypochile longer than the epichile, broadest at the base then tapered, concave; epichile short, indistinct, with incurved margins, entire or notched. Column short, with 2 stigmas and distinct apical wings.

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Size and Distribution

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A genus of 20-30 species distributed in tropical regions of Africa, Asia, South-east Asia, Malesia, Melanesia, Polynesia, New Caledonia and Australia where there is a single non-endemic species, Hetaeria oblongifolia. In Australia Hetaeria oblongifolia is of disjunct and sporadic occurrence in northeastern Queensland between Iron Range (1238 S) on Cape York Peninsula and Rockhampton (1222 S).  State occurrence: Queensland.

Ecology

Hetaeria oblongifolia usually grows on shady slopes and close to streams in moist humid forests, particularly rainforest. Elevation ranges from the lowlands to about 400 m alt. Some exotic species grow on mossy rocks in streams.

Biology

Pollination: The flowers of Hetaeria oblongifolia are probably self-pollinating.

Reproduction: Hetaeria reproduces solely from seed. Seed dispersal takes 1-2 months from pollination and the capsules develop in an erect position. There is no elongation of the peduncle or pedicels. Apomixis is unknown in the genus.

Seasonal Growth: Hetaeria oblongifolia survives the dry part of the year as leafless quiescent plants.

Flowering: Hetaeria oblongifolia flowers between July and October.

Hybrids: Hetaeria oblongifolia does not participate in natural hybridisation.

Fire: Hetaeria oblongifolia does not grow in fire-prone habitats.

Derivation

Hetaeria is derived  from the Greek, hetairos, companionship, an apparent reference to the relationship with other members of the subtribe Goodyerinae.

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Botanical Description

Perennial, deciduous, terrestrial herbs, sympodial. Roots wiry, produced from rhizome nodes, appearing woolly from a covering of root hairs. Rhizome cylindrical, fleshy, unbranched or sparsely branched, prostrate. Stem erect, apical, usually 1 shoot per plant, similar to the rhizome. Pseudobulbs absent. Trichomes present on bracts, ovaries and the exterior of the sepals, sometimes also on peduncle and rhachis, unbranched, multiseriate, eglandular. Leaves lasting 1 season, few per shoot, petiolate, sheathing at the base, dark green, forming a loose central rosette. Leaf lamina longer than wide, convolute, often asymmetric, thin, membranaceous, glabrous, flat, smooth, entire. Venation acrodromus to campylodromus, with cross-veinlets and few anastomoses. Inflorescence spicate, terminal on a growth, erect, few-many-flowered. Peduncle longer than the rhachis, glabrous or hirsute, with sheathing, glabrous or hirsute sterile bracts.  Floral bracts sheathing, hirsute. Ovary elongate, appressed to the rhachis or spreading, asymmetric, straight, hirsute, not twisted. Flowers non-resupinate, small, crowded, dull coloured (greenish, whitish or yellowish), sessile to subsessile, externally glabrous or hirsute. Dorsal sepal free, porrect to recurvedLateral sepals free, usually porrect, sometimes dilated at the base and partially hooding the labellum. Petals free, of similar length to the sepals, asymmetric, membranousLabellum fixed by its basal margins to the anterior margins of the column base, immoveable, markedly dissimilar in size and shape to the sepals and petals, ecalcarate. Labellum lamina obscurely divided; hypochile longer than the epichile, broadest at the base then tapered, with a shallowly pouched base containing 2 groups of small irregular glands; epichile short, indistinct, with incurved margins; apex entire or bilobed. Callus obscure.  Nectar absent. Column short, lacking free filament and style. Column wings apical, tooth-like or arm-like. Column foot absent. Pseudospur absent. Anther dorsal, 2-celled, persistent, basifixed, with an acuminate rostrum. Pollinarium present. Pollinia 2, ellipsoid to clavate, deeply grooved, straight, yellow, sectile, with short caudicles fused to a stipe. Viscidium present, well-developed. Rostellum ventral, elongate, deeply bilobed and forming 2 extended structures flanking the viscidium. Stigmas 2, separate, situated on the apical margins of the column. Capsules dehiscent, hirsute, erect; peduncle not elongated in fruit; pedicels not elongated in fruit. Seeds numerous, elongate, light coloured, winged.

Taxonomy

Within the subtribe Goodyerinae, Hetaeria can be recognised by the non-resupinate hairy flowers, shallowly saccate labellum with 2 basal groups of small glands and apically winged column.

Nomenclature

Hetaeria Blume, Fl. Javae. Appl. 1: Praef. vii (1828).  Type species: Hetaeria oblongifolia (Blume) Blume.

Etaeria Blume, Aetheria Endl. (orth. var.).

Infrageneric Taxa: No infrageneric taxa are recognised.

References

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.

Pridgeon, A.M., Cribb, P.J., Chase, M.W. and Rasmussen, F.N. (eds), (2003). Genera Orchidacearum, Vol. 3. Oxford University Press.

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