Prasophyllum


Prasophyllum, [praise-o-fill-um ] from prasos, a leek, and phyilos, a leaf; referring to the leek-like leaves.

Species of this genus are commonly called “Leek Orchids.’  The genus is easily recognised by the sheathing leaf and spike of small inverted flowers, but many of the species are difficult to determine. The spikes of whitish flowers tinged or streaked with green and purple, are not specially attractive to the flower hunter, yet the beauty of a single bloom when beheld through a magnifying-glass is amazing. The sepals and petals are narrow and inconspicuous. The lip on the upper side of the flower is broad and slightly waved at the edge, often bearing an inner plate. The column is very short.

The various species of Prasophyllum are wholly dependent on insects for fertilisation, and there is a marked difference in the number fertilised according to situation. Sometimes solitary plants will not have a single flower fertilised, yet when growing in groups, generally in a rushy flat-perhaps the haunt of some particular insect – every flower on every plant will be fertilised. Hybridisation of different species is common and no doubt responsible for specimens that have been collected bearing flowers on the same spike having characteristics of species so different as to have been placed by Bentham in separate sections dividing those with a rigid sessile lip from others having the lip on a short claw.

Prasophyllum Species in Western Australia

Prasophyllum attenuatum, attenuated.
A very slender, wiry species, 12 to 18 in. high, leaf 9 in., blade 3 in. Flowers about 40, not dense, on a spike of about 5 in. Lateral sepals not two lines, greenish with white edges, oblong, cucullate at the ends with blunt points. Dorsal sepal about 2 lines oblong, hardly acuminate, slightly recurved. Lip about 2 lines ovate-oblong, pouched at end. Disk about two-thirds length of lip, hardly raised above it, with five slight ridges towards the end. Lower lobe obtuse. (Described Gardener’s Chronicle, XVII., pp495.)
W.A.: Bunbury. September.

Prasophyllum australe, southern.
Often slender, usually over 1 ft. in height. Leaf-blade usually shorter than the spike. Flowers, sessile in a rather loose spike, sweet-scented, with prevailing tints of white, brown and green. Perianth segments all very acute, sepals nearly equal in length, the dorsal one erect or recurved, or recurved, ovate-lanceolate, the lateral ones sometimes free at extreme base, and united beyond almost to the tips. Petals erect yellowish-green with wide reddish-brown stripe down the centre, narrower and rather shorter than the lateral sepals Lip conspicuously white, callous part prominently raised, ending close to the bend, ovary long and very slender. An uncommon species.
W.A.
All Australian States. October-December.

Prasophyllum cucullatum, hooded, referring to the formation of lateral sepals.
A species closely allied to Prasophyllum gibbosum, and considered by Bentharn to be perhaps a variety only, but admitted as distinct by Dr. Rogers. A smaller plant with usually a dense blunt spike, 1 to 1 ½ in. long, of white and purple sweet-scented flowers, but sometimes single-flowered. The lateral sepal. are the shortest segments of the perianth, and are joined a their extreme tips, forming a hood in front of the liPrasophyllum Upper sepal dark purple at the base, purple stripe down centre. Lip on a long springy claw, at first erect, then bent forwards almost at a right angle.
W.A.: Pinjarra, Porongorups, Ravenswood. September – October.

Prasophyllum cyphochillum, curved lip
Stem 1 to 2 ft., leaf-blade short and slender. Flowers small, white tinged with reddish-purple, lip with a swollen base forming a short pouch protruding between the lateral sepals.
W.A.: Albany, Darling Range, Gosnells, Highbury, Perth, Pindalup, Wagin, Welshpool, York, September.

Prasophyllum elatum, “PIANO ORCHID”; tall.
– see Orchid Illustration 2, no 4
This species is well named as it is one of the tallest terrestrial orchids in Australia. West Australian children see a resemblance in the pearly white of the lip and the darkly streaked sepals and petals in the long spikes of closely set flowers to the black and white keys of a piano. The stem is sometimes 6 ft. high, with the long sheath covering a great part of it. Flowers largely white, often dusky, tinged with green and purple, nearly sessile in a spike of 4 to 8 in. or more. Lateral sepals united from about the middle almost to the tips, petals usually spreading. Lip as long as the petals, ovate-oblong, the margins wavy, and the inner plate occupying the greater part of its surface. Lateral appendages exceeding the column in height. A common species found in all classes of country.
W.A.: Widely distributed. September.
New South Wales, South Australia, Tasmania, Victoria,

Prasophyllum ellipticium, referring to shape of lip
A tall, robust plant of about 3 ft. Spike rather crowded with numerous pale green flowers, nearly 1 ft. long. Leaf-blade not reaching to top of spike. Flowers sessile on a slender ovary. Perianth segments (excepting lip) rather narrow; lateral sepals about ½ in. long, upper sepal longer, lateral petals shorter. Lip on a very short claw, elliptical, about ¼ in. long and ¼ in. wide, erect at base, recurved to-wards the tip, outer membraneous margin white, wide and voluminous, much crisped inner plate also membraneous oval, with a rather blunt short apical projection commencing about the bend but not nearly reaching the tip, attached to outer plate at base and apical projection, margin otherwise free. Lateral appendages of column exceeding the rostellum in height. (Described Transactions and Proceedings Royal Society S.A., XLIV., 1920.)
W.A.: Jarnadup December.

Prasophyllum fimbria, fringed.
– see Orchid Illustration 2, no 1
A tall species with the habit and size of flowers of Prasophyllum elatum, but with a very different liPrasophyllum Flowers white, shaded with purple. Sepals nearly ½ in. long, petals shorter, linear. Lip as long as sepals, on a tiny but distinct narrow claw, upper part broad with fringed or crisped margins, inner plate ending above the middle in a broad, free, densely crisped margin, and within it in the centre of the lip, a more or less conspicuous second plate with scarcely prominent entire margins. Distribution general and common.
W.A.: Albany, Darlington, Jarnadup, Mundijong. September December.

Prasophyllum gibbosum, curved.
Stems from under 6 in. to 1 ft., leaf-sheath long, with a long narrow-linear blade. Flowers in a rather dense spike sepals and petals obtuse. Lip nearly as long as the sepals, linear-oblong, the upper part recurved, margin slightly wavy the inner-plate not very conspicuous.
W.A.: Gosnells. September.

Prasophyllum hians, yawning.
Stem 4 in. to 2 ft. or more high, leaf-sheath loose. Flowers white, tinged with reddish-green or with purple markings, in rather a dense spike. Sepals over ¼ in. long, the lateral ones united almost to the apex, very thin and whitish near their line of junction; petals longer than lateral sepals, more dilated than in other species. Lip sessile, rather broad at base, but not swollen, recurved above the middle, margins wavy, the inner-plate much narrower, olive-green coloured, forming a longitudinal central thickening, ending at the bend or a little beyond it, in a thick fringed callus. A common species.
W.A.: Widely distributed. October.

Prasophyllum lanceolatum, lanceolate, referring to the shape of perianth segments and lip
A rather slender plant, about 18 in. high, with two long overlapping tubular sheaths at base of stem. Leaf-blade about 6 in, long, not reaching as high as spike. Spike about 6 in. long. Flowers rather distant, dark reddish-brown segments of perianth narrow-lanceolate, upper sepal nearly ½ in. long, slightly incurved, longer than lateral sepals. Lateral petals shorter. Lip on a very short claw, about ¼ in. long, lanceolate, membraneous border narrow, not crisped, margin entire, almost plain, inner plate relatively large, lanceolate, extending to within a short distance of the apex. (Described Transactions and Proceedings Royal Society, S.A., XLIV., 1920.)
W.A.: Albany, Muresk, Perth. October.

Prasophyllum macrostachyum, long spike.
A slender plant; flowers, greenish-white, sometimes deep purple rather distant in a long spike. Lateral sepals awl-shaped, twice as long as petals.  This orchid is occasionally found with the spike once-forked for about half its length, giving it a double-headed appearance.  A light green variety favours moist places in loamy clay soil, and dark purple flowered form is found on clay flats covered in winter months with standing water.
W.A.: Albany, Dumbleyung, Highbury, Katanning, Kojonup, Midland Junction, Narrogin, Pindalup, Swan View, Wandering, September – October.

Prasophyllum Muelleri, honouring F. von Mueller.
A tall plant, often 4 ft. in height, differing from Prasophyllum elatum in that the lip instead of being sessile is hinged on a short claw. Lateral sepals often quite free. Favours stony ridges.
WA.: Swan View. September.

Prasophyllum ovale, oval.
Stem slender, above 1 ft. high, leaf-sheath and blade long. Flowers small, white tinged with green and purple, in a spike of 3 to 6 in., not dense. Lateral sepals and petals linear, all nearly equal, upper sepal white, wider than other segments. Lip nearly as long as lateral sepals, oval, membraneous part white, with entire margins, slightly scalloped towards the tip, callous part smooth, green. triangular, extending from the base to slightly beyond the middle, shiny, glandular, much narrower than the membraneous part, not swollen at base. A common species.
W.A.: Albany, Darlington, Gosnells, Highbury, Kalamunda, Narrogin, Perth, Pindalup, Stirling Range, Wagin, York, September- October.

Prasophyllum ovale var. triglochin,
Note by Dr. Rogers “Lateral petals 2.5 mm, long; sepals 3 mm. long; labellum oval or bluntly elliptical, 2.5 mm. long. The leaf of this species is stated by Bentham to have a long lamina. An examination of a large number of specimens in the field and herbarium indicate that the leaf-lamina is almost invariably short as in the case of Prasophyllum cyphochlum.
W.A.: Lake Chockerup

Prasophyllum parvifolium, small-leaved.
Stem slender, 9 in. to over 1 ft. high, the leaf above the middle of the stem, with a short slender blade. Flowers white and green, faintly streaked with crimson, five seven or less, in a loose raceme of 2 or 3 in.
W.A. Albany, Bayswater, Busselton, Greenmount, Kalamunda, Muresk, Swan View, June-September.

Prasophyllum plumaforme, feathery.
A slender species, 12 to 18 in. high. Leaf about 6 in., blade hardly 2 in. Flowers about 40 in a long feathery spike.
Sepals and petals oblong, acuminate, about 2 lines. Lateral sepals white with green stripes. Dorsal sepal red-brown edged with white. Petals white with purple stripe. Lateral sepals not united. Lip not curved, oblong, tapering, slightly reflexed for about one-third of its length, two parallel raised lines on the disc. Lateral appendages of column falcate, acuminate; unequally two-lobed. Rostellum slender, longer than the appendages, anther short, hardly acuminate. (Described Gardener’s Chronicle, XVII., pp495.)
W.A.: Albany. August.

Prasophyllum regium, king-like.
A robust plant up to 3 ½ ft. or more, leaf not reaching to top of flower-spike. Flowers white, tinged with green and purple, in a rather loose spike sometimes 16 in. long, cormposed of upwards of 50 flowers, with lower blossoms distant. Lip on a distinct claw, recurved at right angles, inner plate thin, membraneous, orbicular-lanceolate, margin entire, extending nearly to tip, no secondary plate. Lateral appendages of column exceeding rostellum in height. (Described Transactions Royal Society S.A., Vol. XLII., 1918.)
W.A.; Manjimup December.

Prasophyllum triangulare, triangular-shaped lip
A rather robust species, 12 in. or more high, very dark coloured. Leaf about 10 in. long, blade about 5 in. Flowers dark red brown, about 30 in a long spike, lateral sepals united almost to their points, together ovate-acuminate, glandular at base and along joined edges. Dorsal sepal rather longer, about 3 lines. Petals lanceolate, shorter than sepals. Lip about 2 lines on a rather long claw, triangular, very slightly recurved, edges entire, slightly undulate, the disc forming a raised triangular plate nearly as large as lip, somewhat swollen towards point and irregularly covered with small sessible calli. Appendages to column broad at base, falcate, acuminate, equal in length to rostellum, thickened on outer margin with three or more callosities. Anther much shorter than rostellum, hardly acuminate. (Described Gardener’s Chronicle, XVII., pp495.)
W.A.: Albany. October.

West Australian Orchids Series

  1. West Australian Orchids
  2. Orchid Illustration 1 - Caladenia
  3. Orchid Illustration 2
  4. Orchid Illustration 3
  5. West Australian Orchid Types
  6. Naming and Classification of Orchids
  7. Structure, Fertilization and Reproduction of Orchids
  8. Collection of Orchids
  9. Glossary of Orchid Terms
  10. Caladenia
  11. Diuris
  12. Drakea
  13. Eriochilus
  14. Glossodia
  15. Leptoceras
  16. Lyperanthus
  17. Microtis
  18. Prasophyllum
  19. Pterostylis
  20. Thelymitra

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