Slender hyacinth orchid | |
---|---|
Dipodium variegatum in Meroo National Park | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Orchidaceae |
Subfamily: | Epidendroideae |
Genus: | Dipodium |
Species: | D. variegatum |
Binomial name | |
Dipodium variegatum | |
Dipodium variegatum, commonly known as the slender hyacinth-orchid, [2] or blotched hyacinth-orchid, [3] is a leafless mycoheterotrophic orchid that is endemic to south-eastern Australia. It forms mycorrhizal relationships with fungi of the genus Russula .
Dipodium variegatum is a leafless, mycoheterotrophic orchid. For most of the year, it lies dormant and has no above-ground presence; its tubers grow fleshy roots and form shoots consisting of leaf-like, sharply pointed, overlapping bracts, sometimes protruding above the ground, from which inflorescences emerge. The plant blooms in December-February, and the unbranched flowering stem, 15–60 cm (6–20 in) tall, carries 2-50 flowers. The blossoms are fleshy and cream-coloured to light pink with maroon blotches. The sepals and petals are 11–15 mm (0.43–0.59 in) long, 3–5 mm (0.12–0.20 in) wide, and slightly reflexed. The labellum is 6–15 mm (0.2–0.6 in) long and mauve to maroon. There are two diverging linear, hairy keels near the base of the labellum and a band of mauve hairs about 1 mm (0.04 in) long along its midline. The ovaries are curved with a warty surface. Along with the pedicels they are covered in conspicuous maroon spotting and together are 10–17 mm (0.39–0.67 in) long. [3] [4] A form with sepals and petals that are completely dark maroon occurs in some parts of its distribution. [2]
Dipodium variegatum is similar to D. roseum , but the latter species has converging keels on the labellum and lacks the dense patch of tangled hairs near the tip of the labellum of D. variegatum. Also, of the Dipodium species that occur in Australia, D. variegatum is the only to have distinctly spotted ovaries (and sometimes pedicels). [3]
Dipodium variegatum was first formally described in 1987 by Australian botanists Mark Clements and David Jones and the description was published in Proceedings of the Royal Society of Queensland . The type specimen was collected beside the Pacific Highway in Beenleigh, Queensland. [5] The specific epithet (variegatum) is a Latin word meaning "of different sorts, particularly colors". [6]
Dipodium variegatum occurs in eastern parts of Queensland as far north as the Mount Windsor Tableland west of Daintree National Park and in New South Wales as far west as Temora. In Victoria it is only found in the far east. It grows in a wide range of habitats from heath to wet forests. [4]
Recovered DNA shows that this orchid forms mycorrhizal associations with Russula solaris and R. occidentalis , in keeping with the observation that many members of the genus form relationships with fungi of the family Russulaceae. [7] The orchid has been observed to occur in close proximity to Eucalyptus species and it is thought that a relationship exists with these trees through this mycorrhizal association. [8]
Pollination of this species, as for all species in the genus, is by native bees and wasps. [2]
The species is listed as "rare" on the Victorian Department of Environment and Primary Industries advisory list of rare or threatened plants in Victoria. [9]
No leafless species of Dipodium has been sustained in cultivation due to the inability to replicate its association with mycorrhizal fungi in a horticultural context. [2]
Dipodium, commonly known as hyacinth orchids, is a genus of about forty species of orchids native to tropical, subtropical and temperate regions of south-east Asia, New Guinea, the Pacific Islands and Australia. It includes both terrestrial and climbing species, some with leaves and some leafless, but all with large, often colourful flowers on tall flowering stems. It is the only genus of its alliance, Dipodium.
Dipodium punctatum, commonly known as the blotched hyacinth-orchid, is a leafless orchid that is a native to eastern and south-eastern continental Australia. In summer it produces a tall flowering stem with up to sixty pale to bright pink flowers with heavy red blotches. A widespread and common species it is often confused with D. roseum and some authorities regard it as a synonym of D. squamatum.
Dipodium elegantulum, commonly known as the elegant hyacinth orchid, is a leafless orchid that is endemic to Queensland. In spring and summer it has up to sixty pale to dark pink flowers with a few darker spots and streaks near the tips, on a tall flowering stem.
Dendrobium tetragonum, commonly known as the tree spider orchid, is a variable species of epiphytic or lithophytic orchid endemic to eastern Australia. Tree spider orchids are unusual in having pendulous pseudobulbs that are thin and wiry near the base then expand into a fleshy, four-sided upper section before tapering at the tip. There are only a few thin but leathery leaves at the end of the pseudobulbs and up to five flowers on relatively short flowering stems. To allow for the variations in the species there are five subspecies and a variety, some with a unique common name.
Dipodium roseum, commonly known as rosy hyacinth-orchid or pink hyacinth-orchid, is a leafless saprophytic orchid found in east and south-eastern Australia. In summer it produces a tall flowering stem with up to fifty pale pink flowers with small, dark red spots. A widespread and common species it is often confused with D. punctatum but has darker, less heavily spotted flowers.
Cryptostylis hunteriana, commonly known as the leafless tongue-orchid is a flowering plant in the orchid family Orchidaceae and is endemic to south eastern Australia. It is leafless but has up to ten green flowers with a more or less erect, dark reddish brown labellum.
Aphyllorchis queenslandica, commonly known as the yellow pauper orchid, is a leafless terrestrial mycotrophic orchid in the family Orchidaceae. It has up to twelve dull yellow flowers on a thin, fleshy, purple flowering stem and is endemic to tropical north Queensland where it grows in rainforest.
Gastrodia sesamoides, commonly known as cinnamon bells or common potato orchid in Australia and as the pot-bellied orchid or cinnamon sticks in New Zealand, is a leafless, terrestrial saprophytic orchid in the family Orchidaceae. It has a thin, fleshy brown flowering stem and up to twenty five drooping, brownish, self-pollinating flowers that are white inside. Growing in a wide range of habitats, it is native to Australia and New Zealand.
Dipodium hamiltonianum, commonly known as yellow hyacinth-orchid, is a leafless mycoheterotroph orchid that is endemic to eastern Australia. It has up to twenty five greenish flowers with dark red spots on a tall flowering stem.
Dipodium pardalinum, commonly known as spotted hyacinth-orchid or leopard hyacinth-orchid, is a leafless hemiparasitic orchid that is endemic to south-eastern Australia.
Dipodium campanulatum, commonly known as the bell-flower hyacinth orchid, is a leafless mycoheterotroph orchid that is endemic to south-eastern Australia. In summer it has up to thirty five white flowers with large, dark red spots and blotches.
Dipodium stenocheilum, commonly known as tropical hyacinth-orchid, is a leafless saprophytic orchid that is endemic to northern Australia. For most of the year the plant is dormant but in summer it produces a tall flowering stem with up to twenty five white flowers with purple spots and a mauve labellum.
Dipodium ensifolium, commonly known as leafy hyacinth-orchid, is an orchid species that is endemic to north-east Queensland. It has sword-shaped leaves and up to twenty pink to mauve flowers with purplish spots and blotches.
Dipodium atropurpureum, commonly known as the purple hyacinth orchid, is a mostly leafless mycoheterotrophic orchid that is endemic to New South Wales. In summer it has up to forty dark pinkish purple to reddish purple flowers with darker spots and blotches on a tall flowering stem.
Dipodium pulchellum is an almost leafless orchid that is endemic to north-east New South Wales and south-east Queensland in Australia. Up to forty pink flowers with darker blotches are borne in summer and winter on flowering spikes up to 90 cm (40 in) long.
Caladenia atroclavia, commonly known as the black-clubbed spider orchid, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Queensland. It is a ground orchid with a single hairy leaf and a pale greenish-cream coloured flower with dark purple clubs and red patches on the petals.
Caladenia actensis, commonly known as the Canberra spider orchid, is a plant in the orchid family Orchidaceae and is endemic to the Australian Capital Territory. It has a single leaf and usually only one greenish flower with red markings and only occurs in three small populations.
Arthrochilus sabulosus, commonly known as the spotted elbow orchid, is a flowering plant in the orchid family (Orchidaceae) and is endemic to Tropical North Queensland and Horn Island. It has a rosette of dull green leaves on side growth at its base and up to fifteen pale green, insect-like flowers with reddish to brownish glands on its labellum.
Epipogium roseum, commonly known as ghost orchid, leafless nodding orchid or 虎舌兰 , is a leafless terrestrial mycotrophic orchid in the family Orchidaceae. It has up to sixteen cream-coloured, yellowish or pinkish flowers with an enlarged ovary on a fleshy hollow flowering stem. This ghost orchid is widely distributed in tropical Africa, Asia, Southeast Asia, New Guinea, Australia and some Pacific Islands.
Rhizanthella speciosa is a species of flowering plant in the orchid family and is endemic to Barrington Tops in New South Wales. It is a mycoheterotrophic herb that spends its entire life cycle, including flowering, at or below the soil surface.