The New Zealand Forms of Calochilus R.Br.
[Read before the Auckland Institute, August 20, 1947; received by the Editor, October, 10, 1947; issue dseparately, February, 1949.]
Acknowledgments.—The writer is indebted to Rev. H. M. R. Rupp, of Sydney, Mr. W. H. Nicholls, of Melbourne, Mr. K. W. Allison and Miss B. E. G. Molesworth, for specimens, photographs and drawings.
Pollination.—In Australia C. campestris is pollinated by the Scoliid wasp Campsomeris tasmaniensis. In the Victr. Natr., 62, 1946, 199, Fordham describes how the insect alights on the labellum, goes through a series of deliberate movements of an apparently sexual nature, and carries the pollinia away adhering to the front of the head. On repeating the performance on another flower the pollinia are deposited on the conveniently placed stigma and a new lot of pollinia removed. The attraction appears to be the coloured glandular hairs which the wasp spends some time caressing as it works up towards the column.
Key to N.Z. Species.
|1. Column with a dark callus on either side at the base||2|
|Column with no basal calli||paludosus|
|2. Basal calli connected with a conspicuous coloured ridge||robertsonii|
|Basal calli connected by a broken line of irregular reddish splashes||campestris|
Calochilus R. Br.
Terrestrial glabrous herbs with ovoid tubers. Leaf solitary or wanting, sheathing at the base, conspicuously channelled, linear-acuminate. Stem bracts often foliaceous, 1–4, acuminate, loosely sheathing. Floral bracts similar to the stem bracts, smaller. Flowers up to 15 in a lax terminal raceme, yellow- to purplish-green with dark striae. Dorsal sepal cucullate or reflexed, acute. Lateral sepals about the same length, usually narrower. Petals narrower again, shorter, spreading. Labellum much longer than the sepals, sessile, ovate triangular or trapezoid, either glabrous or densely plumose with coloured glandular hairs. Apex usually produced into a glabrous ribbon. Column short, broadly winged, with or without conspicuous paired calli at the base. Stigma broad, high under the anther. Rostellum erect. Anther large, terminal, erect or horizontal, obtuse or acute, 2-celled. Pollinia 4 (occasionally 2 bilobed), pollen granular.
A genus of 11 species, nine in Australia, one in New Guinea and one in New Caledonia. Three of the Australian species extend to New Zealand. Calochilus has some affinity with Thelymitra (flowerless plants are easily confused), and the two possibly had a common origin very far back. The genus appears to have originated in Australia and to have been windborne across the Tasman.
1. Calochilus campestris B. Br. Prodr., 1810, 320. Hatch, Trans. R.S.N.Z., 76, 1946, 59.
C. cupreus Rog., Trans. R. S. South Austr., 42, 1918, 24.
Up to 70 cm. high. Flowers 1–15, greenish-yellow with pink striae. Labellum lanceolate; base a succulent rectangle with four roughly parallel linear calli, the whole violet-blue; lamina greenish-yellow, sparsely covered with long glandular hairs varying from copper through red to blue; apex either acuminate or produced into a sinuous glabrous ribbon. Column with a conspicuous dark callus on either side near the base, the calli joined by a broken line of irregular reddish splashes. Anther horizontal.
Distribution.—Australia—common throughout all the States except Western Australia. New Zealand—2, Kaimaumau, 11, 1924, et subseq., H. B. Matthews.
Flowers October–November. Sea-level–2,000 ft., grass, roadsides and scrub. Matthews collected this species for some five years in succession about Kaimaumau. He left photographs and description of the living plants (MS. “C. viridi-sanguineus”) which compare exactly with Australian material. A strange form with an almost glabrous labellum was for some time considered to be a new species, but recent developments reveal that it is inconstant and is most likely of hybrid origin. This is the “fourth still under consideration” of Rupp's review of the genus in Proc. Linn. Soc. N.S.W., 71, 1947, 287.
The illustration in Curtis's Botanical Magazine, 1832, t. 3187, can be regarded as the hypotype of the species. New Zealand specimens in Herb. Rupp and in the Auckland Museum.
2. Calochilus robertsonii Benth. Fl. Austr., 6, 1873, 315.
C. campestris Cheesmn. (not of R. Br.).
Up to 40 cm. high. Flowers 1–8, greenish-purple with darker striae. Labellum ovate-acuminate; base covered with short calli; lamina densely plumose with reddish-purple hairs; apex produced into a glabrous sinuous ribbon. Column with the basal calli conspicuously connected by a transverse purple ridge. Anther very long, almost horizontal, sub-acute.
Distribution.—Australia—common throughout. New Zealand—5. Not uncommon between Rotorua and Taupo, Hatch, Allison, Matthews, etc.
Flowers September–December. Sea-level–2,000 ft., small colonies on roadsides, in tussock and in scrub. Cheeseman (Manual, 1906, 686) identified this plant with C. campestris by comparison with Fitzgerald's plate in Austr. Orch., 1, 1878, 4. But Nicholls has proved (Vict. Natr., 58, 1941, 94, t—and Rupp also independently, Orch. N.S.W., 1943, 49) that Fitzgerald's illustration was in reality C. robertsonii Benth., and did not compare with the hypotype of C. campestris in the Botanical Magazine (see under previous species). This error on Fitzgerald's part led to the creation of C. cupreus Rog. to account for the “nameless” plant (actually C. campestris) which occurred over most of Australia. To clinch the matter—all the N.Z. specimens collected by the writer, and all those collected by Allison,
Plant of Calochilus robertsonii natural size.
a. C. campestris—flower from side. b, Column from side.
c. Column-base and labellum.
d. C. robertsonii—flower from side. e, Column from side.
f. Column-base and labellum.
g. C. paludosus—flower from front. h. Column-base and labellum.
j. Column from side. (c, f, h after Rupp.)
Matthews, Mellor, Spencer and Petrie correspond exactly with the original description of C. robertsonii and do not agree with the hypo-type of C. campestris.
3. Calochilus paludosus R. Br. Prodr., 1810, 320.
Up to 90 cm. high. Flowers 1–15, rather large and expanding more widely than in the other species, dark-green with darker striae. Labellum lanceolate; base covered with short calli and with a narrow callous ridge on either side; lamina densely plumose with lustrous red hairs; apex produced into a long, rather broad, straight ribbon. Column with no basal calli. Column-wings conspicuously large. Anther short, broad, obtuse.
Distribution.—Australia—Queensland, N.S.W., Vict., Tasmania, not uncommon. New Zealand—2, Kaitaia, R. H. Matthews; Aponga, A. Thompson; 5, common about Rotorua, Petrie, Matthews, Allison; 7, Tararua Ranges, 11, 1911, B. C. Aston; 10, Collingwood, H. H. Travers, Westport, W. Townson.
Flowers October-December. Sea-level–1,500 ft., small colonies about swamps or in tussock.
Coleman, E., 1946. Vict. Natr., 63, 48—C. caerulea L. O. Williams, New Guinea.
Nicholls, W. H., 1943. Vict. Natr., 59, 158t—C. saprophytious Rog.