Family: Orchidaceae
Prasophyllum
Citation:
R. Br., Prod. Fl. Nov. Holl. 317 (1910).
Derivation: Greek prason, a leek; phyllon, a leaf.
Synonymy: Not Applicable Common name: None
Description:
Terrestrial glabrous herbs from diminutive to large, with ovoid or globular tubers, new tuber produced distant from that of the previous year; leaf solitary, lamina terete, hollow.
Flowers not resupinate, several or numerous in a raceme, from diminutive to moderate-sized, sometimes fragrant; bracts smaller than the ovary; perianth usually inconspicuous, commonly greenish, white or purple; dorsal sepal lanceolate or broad and acute, concave, sometimes erect and arched over the column, more frequently recurved; lateral sepals narrower, connate to free; petals usually shorter, lanceolate or linear; labellum above the column, sessile or on a movable well-developed claw attached to the base of the column, more or less trullate, undivided, usually erect and concave towards the base, recurved distally; margins crisped, ciliate, denticulate or entire; calli on the labellum simple and more or less longitudinal; column short below the anther; its margins produced into wings in the form of 2 free lateral processes, usually adnate to the basal margins of the stigmatic-plate (a vertical plate in front of the anther, consisting of a basal portion or an expanded style, and an upper portion bearing the stigma and the rostellum); rostellum prominent, becoming detached, with a thread-like stipe to which pollen masses adhere; pollinia 2, 2-lobed in each cell, pollen in many small oblong masses; stigma disc-shaped.
Distribution:
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80-90 species, the majority temperate Australian; 4 in New Zealand and New Caledonia. Leek-orchids (spring-flowering), midge-orchids (autumn-flowering).
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Biology:
The autumn-flowering species with the labellum on a movable claw are pollinated by tiny flies, the spring- and summer-flowering species with a non-movable labellum are pollinated principally by nectar- seeking insects, mainly wasps.
Key to Species:
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1. Column stem elongated; labellum on a movable claw; leaf clasping the stem for most of its length (autumn-flowering plants, section Micranthum) |
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P. morrisii 10. |
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P. archeri 1. |
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4. Labellum lanceolate, tapering into a long acute point |
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P. despectans 3. |
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4. Labellum obovate, acute or subacute |
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5. Petals greenish; labellum margin entire with a subacute apex; column appendage posterior lobe acuminate; anther mucro short, less than 0.1 mm long |
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P. nigricans 11. |
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5. Petals reddish; labellum margins serrate toward an acute apex; column appendage posterior lobe rounded; anther mucro long, c. 0.3 mm, bristle-like |
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P. rufum 14. |
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1. Column stem condensed; labellum not on a movable claw; leaf clasping basally, free for at least one-third of its length (spring- flowering plants, section Prasophyllum) |
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6. Ovary appressed to the stem, long, slender and flattened dorsiventrally |
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7. Labellum acutely reflexed about the middle, conspicuously white, base gibbous |
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P. australe 2. |
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7. Labellum slightly recurred from about the middle, the base not gibbous |
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P. elatum 4. |
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6. Ovary standing out from the stem, more or less turgid |
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8. Flowers not expanding, the floral segments very dark and parchment-like |
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P. goldsackii 7. |
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8. Flowers freely expanding, the floral segments green to reddish |
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9. Labellum callus with some pubescence |
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10. Flowers wholly greenish; lateral sepals 2-dentate; normally a tooth-like spur at the base of the column |
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P. pallidum 12. |
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10. Flowers with some purple or reddish tints; lateral sepals not 2-dentate; no tooth-like spur at the base of the column |
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P. fitzgeraldii 5. |
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9. Labellum callus without pubescence |
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11. Flowers less than 5 mm diam., segments to 2 mm long; column appendages absent or vestigial |
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P. macrostachyum 9. |
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11. Flowers more than 6 mm diam., segments more than 2.5 mm long; column with distinct appendages |
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12. Labellum usually with a lateral constriction near the tip; callus plate extending beyond the bend almost to the tip (narrow but much raised) |
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P. fuscum 6. |
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12. Labellum without a lateral constriction near the tip; callus plate hardly exceeding the bend, never reaching the tip (broad and not much raised) |
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13. Lateral sepals longer than the labellum; labellum base orbicular, broad, margins much incurved; callus plate with thickened glandular margins |
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P. hartii 8. |
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13. Lateral sepals shorter than the labellum; labellum base ovate, without markedly incurved margins; callus plate without thickened margins |
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P. patens 13. |
Author:
Not yet available
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