Acianthus R.Br.

Genus

Angiosperms > Asparagales > Orchidaceae

Characteristics

Deciduous, terrestrial orchids forming spreading, clonal colonies that are sometimes dense and often have a low proportion of plants flowering. Leaf single, held horizontally above ground-level on a fleshy stalk, heart-shaped, under-surface purplish red (sometimes green). Racemes erect, multiflowered; peduncle longer than rachis, fleshy. Flowers resupinate, small, pinkish, greenish or purplish, resembling tiny insects. Sepals free, larger than petals; apex with thin cylindrical osmophore (club). Dorsal sepal larger than lateral sepals; cucullate over column, or spreading. Lateral sepals porrect beneath labellum. Petals free, small, spreading or reflexed against ovary. Labellum attached by base to column base. Labellum lamina unlobed, porrect, base with shallow basin-like area, margin finely toothed. Callus dominating labellum: large, fleshy with central channel and two prostrate, tonsil-like glands at base. Column curved, slender, wingless. Anther with 8 pollinia in two pairs of four, each unit of four attached to viscidium.
More
Raceme of few to many fls; floral bracts membr. to foliaceous. Per. glab.; dorsal sepal uppermost, concave, ± arched over column; lateral sepals and petals narrower. Labellum shortly if at all clawed, undivided and with entire margins and 2 basal calli. Column semi-terete, incurved above; anther standing at least partly above stigma, pollinia mealy; stigma prominent; rostellum us. 2-lobed. Plants terrestrial, glab.; tubers small, globose, the new ones often remote from the parent plant. Green lf solitary, petiolate on non-flowering stems, sessile on flowering stem; lamina short and broad, length rarely 2 × width. Some 20 spp. described, most of them from New Caledonia; of 5 Australian spp. 3 are represented in N.Z. Also recently recorded from Solomon Is and New Guinea.
Life form perennial
Growth form herb
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Foliage retention deciduous
Sexuality hermaphrodite
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Environment

These orchids grow in sheltered areas of moist to wet forest and heathland in freely draining soil; often under cover of shrubs and bracken.
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Hardiness (USDA) 8-11

Usage

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Edible -
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Cultivation

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Images

Acianthus unspecified picture

Distribution

Acianthus world distribution map, present in Australia and New Zealand

Identifiers

LSID urn:lsid:ipni.org:names:28588-1
WFO ID wfo-4000000273
COL ID 8VT75
BDTFX ID -
INPN ID 672336
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Acianthus

Lower taxons

Acianthus caudatus Acianthus exsertus Acianthus sinclairii Acianthus fornicatus Acianthus ledwardii Acianthus amplexicaulis