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Volume 75, 1945-46
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Notes on New Zealand Orchids.

[Read before the Auckland Institute, July 18, 1945; received by the Editor, July 24, 1945; issued separately, December, 1945.]

A. Corybas Salisb. Parad. Lond. 1805., antedates Corysanthes R. Br. Prodr. Fl. Nov. Holl. 1810. Vigorous efforts to conserve Brown's name having failed, it becomes necessary to adopt Corybas for the New Zealand species. The requisite name changes are here made, and a key added.

1. Corybas aconitiflorus Salisb. Parad. Lond. 1805. t. 83. (incorrectly figured).

Corysanthes bicalcarata R.Br. Prodr. 1810, 328.

C. cheesemanii Hook. f. ex T. Kirk. Trans. N.Z. Inst. 3. 1871. 180.

Cheeseman's opinion (Manual N.Z. Fl. 1906. 693.) that this might prove identical with the Australian C. bicalcarata, was confirmed by Rupp, Rogers, and Nicholls, but Brown's name was never taken up by New Zealand authors, and must give place to the earlier nomenclature of Salisbury.

2. Corybas unguiculatus (R.Br.) Reichb. f. Beitr. Syst. Pfl. 43.

Corybas malthewsii (Cheesmn.) Schltr. Fedde. Repert. 19. 1923. 23.

Corysanthes unguiculata R.Br. Prodr. 1810. 328.

C. matthewsii Cheesmn. Trans. N.Z. Inst. 31 1899. 351.

The writer always considered Cheeseman's C. matthewsii to be very closely related to C. unguiculatus. In a recent letter from Sydney, H. M. R. Rupp expresses his conviction that the two are identical. He recommends a comparison of Cheeseman's figures in Illus. N.Z. Fl., 2. 1914. t. 199a., with those of R. D. Fitzgerald's Austr. Orch. 1. 4. 1876., and of W. H. Nicholls in Proc. Linn. Soc. N.S.W., 53. 1928. t. 12. A subsequent study of photographs of living plants of both Australian and New Zealand forms, combined with a critical examination of specimens, has proved the accuracy of Rupp's conclusions.

3. Corybas carsei (Cheesmn.) Hatch, comb. nov.

Corysanthes carsei Cheesmn. Trans. N.Z. Inst. 44. 1911. 162.

4. Corybas oblongus (Hook. f.) Reichb. f. ibid. 67.

Corybas rotundifolius (Hook. f) Reichb. l.c.

Corysanthes oblonga Hook. f. Handbk. N.Z. Fl. 1864. 266.

C. rotundifolia Hook. f. l.c.

Nematoceras oblonga Hook. f. Fl. Nov. Zel. 1. 1853. 250. t. 57. b.

N. rotundifolia Hook f. ibid. 251.

5. Corybas macranthus (Hook. f.) Reichb. f. l.c.

Corysanthes macrantha Hook. f. Handbk. N.Z. Fl. 1864. 266.

C. rotundifolia Cheesmn. Manual N.Z. Fl. (not of Hook. f.).

C. papillosa Col. Trans. N.Z. Inst. 16, 1884. 337.

Nematoceras macrantha Hook. f. Fl. Nov. Zel. 1. 1853. 249. t. 57a.

The validity of Corysanthes rotundifolia Hook. f. is very much in doubt. Recent investigation has proved that we cannot cite leaf shape as a specific characteristic, since orbicularis leaves have been found to occur in all the species. The C. rotundifolia of the Handbook

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was, according to Hooker, “perhaps a variety of C. oblonga”; Cheeseman admitted his inability to define Hooker's species, and compared C. rotundifolia with small forms of C. macrantha. But nothing could be more distinct than the tubular, fimbriate labellum of C. oblonga, and the expanded, entire or variously lobed labellum of C. macrantha. Obviously Hooker and Cheeseman were considering orbicular-leaved forms of two distinct species. The C. rotundifolia of the Manual was, in fact, C. macrantha; while that of Hooker's Handbook was C. oblonga.

6. Corybas trilobus (Hook. f.) Reichb. f. l.c.

Corysanthes triloba Hook. f. Handbook N.Z. Fl. 1864. 265.

C. hypogea Col. Trans. N.Z. Inst. 16. 1884. 336.

Nematoceras triloba Hook. f. Fl. Nov. Zel. 1. 1853. 250.

7. Corybas rivularis (A. Cunn.) Reichb. l.c.

Corysanthes rivularis (A. Cunn.) Hook. f. Handbook N.Z. Fl. 1864. 266.

Nematoceras rivularis (A. Cunn.) Hook. f. Fl. Nov. Zel. 1. 1853. 251.

Acianthus rivularis A. Cunn. Precur. 1836. n. 312.

Key.
1. Lateral sepals and petals shorter than the labellum, minute or wanting—Section Corysanthes R. Br. 2.
Lateral sepals and petals elongated into filiform caudae—Section Nematoceras Hook. f. 4.
2. Labellum with two conical spurs at the base C. aconitiflorus.
Labellum with two rounded auricles at the base 3.
3. Calli confined to the median line of the labellum C. unguiculatus.
Calli spreading on either side of the median line C. carsei.
4. Labellum fimbriate, distal portion tubular, leaf reddish C. oblongus.
Labellum not fimbriate, distal portion expanded, leaf silvery 5.
5. Dorsal sepal filiform-caudate, leaf acuminate C. rivularis.
Dorsal sepal acuminate, leaf mucronate C. macranthus.
Dorsal sepal orbicular-concave, emarginate, leaf trilobate C. trilobus.

B. Caladenia carnea R. Br. var. minor (Hook f.) Hatch. comb. nov.

C. carnea var. pygmaea Rupp. Proc. Linn. Soc. N.S.W. 69. 1944. 74. (not of Rogers).

C. minor Hook. f. Fl. Nov. Zel. 1. 1853. 247. t. 56.b.

C. variegata Col. Trans. N.Z. Inst. 17. 1885. 248.

In Proc. Linn. Soc. N.S.W. l.c., Rupp reduced Cheeseman's Caladenia exigua to a variety of Brown's C. carnea. In the same paper he quoted C. minor Hook. f. as a synonym of C. carnea var. pygmaea Rog. While there can be no doubt that C. minor belongs to the compound group of C. carnea, there is considerable doubt that it is conspecific with var. pygmaea. Rupp himself subsequently reconsidered the group and agreed with the writer that C. minor was worthy of varietal rank. Hooker, in the Handbook N.Z. Fl. 1864. 267., puts a footnote to C. lyallii, “very closely allied indeed to the Australian C. carnea.” This is obviously an error, since C. lyallii belongs to that section of the genus in which the labellum has four rows of calli, whereas in C. carnea (and incidently in C. minor) only two rows of calli are to be found. It seems probable that this footnote was intended by Hooker to follow the preceding description (C. minor) and that its appearance under C. lyallii was due to a typographical error.

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C. Acianthus fornicatus R. Br. var. sinclairii (Hook. f.) Hatch comb. nov.

Acianthus sinclairii Hook. f. Fl. Nov. Zel. 1. 1853. 245.

The writer has co-operated with several Australian botanists in comparing the respective forms of this species, and it is his considered opinion that Hooker's A. sinclairii is far too close to the Australian form to warrant specific rank. The floral morphology is identical, but there is a number of consistent minor points which separate the two. These are tabled below.

sinclairii fornicatus
Plant consistently very small, seldom more than 8 cm. high. Plant very variable, frequently exceeding 30 cm.
Leaf usually cauline. Leaf usually basal.
Flowers close together upon the peduncle. Flowers distant.
Peduncle elongating only slightly after fertilisation. Peduncle elongating considerably.

D. Prasophyllum nudum Hook. f. Fl. Nov. Zel. 1. 1853. 242.

Pr. tunicatum. Hook. f. l.c.

Pr. rufum Cheesmn. Manual N.Z. Fl. 1906. 676. (not of R. Br.).

Cheeseman identified his Pr. “rufum” by comparisons with Fitzgerald's plate in Austr. Orch., 2. 1891. 4. But Nicholls has proved. (Rupp. Orch. N.S.W. 1943. 143.) that Fitzgerald's plate does not represent Brown's species but is apparently an undescribed form. We must therefore again apply Hooker's name to the New Zealand species. This plant has caused much confusion from the time of its earliest discovery, and fresh material from both North and South Islands is needed before any definite conclusions can be drawn regarding the number of New Zealand species included under the name Pr. nudum.

E. Pterostylis humilis Rog. Trans. Roy. Soc. S. Austr., 46. 1922. 151.

Pt. confertifolia Allan. Trans. N.Z. Inst., 56. 1925. 32.

This endemic species was described from material collected by H. B. Matthews on Mt. Ruapehu. Topotypical specimens of Pt. humilis were compared with the holotype of Pt. confertifolia by Allan and Zotov independently—both confirming the writer's opinion that the two were identical. Pt. trifolia Col. was described from a single imperfect specimen collected by Olsen on the Ruahines in 1898. The holotype has never been available, and the description is incomplete, so that the character of the column and stigma cannot be ascertained. Cheeseman, in the 1906 Manual, placed it hesitatingly in Pt. venosa Col. but Rogers, describing Pt. humilis, expressed the opinion that it could not be included in Pt. venosa and placed it as a doubtful synonym of the new species. Colenso himself was very definite that Pt. trifolia was distinct from any then-described species, and as there is little likelihood of our ever knowing the exact identity of this much discussed form, it seems best to write it off as a nomen dubium.

Pt. humilis is excellently adapted for self-fertilisation. While it is possible for insects to effect cross-pollination, there seems little doubt that at least 75% of the capsules are impregnated by pollen from their own anthers. The column is erect, so that the anther is directly

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above the stigmatic plate. (In the familiar Pt. banksii R. Br. the column is inclined forward, so that the anther is altogether out of alignment with the stigma.) The pollinia are extremely sensitive, the slightest touch to the flower being sufficient to cause them to fall. The stigma is globose and very large, protruding forward beyond the vertical line of the anther. The column-wings have the lower lobes strongly incurved and almost touching the stigma—so that the falling pollinium is caught between them and the viscid surfaces of the stigma cells. Of the five hundred odd plants observed by the writer during 1942–5, every one set seed, whereas in the same locality Pt. banksii was just as consistently infertile.

F. Pterostylis banksii R. Br. ex A. Cunn. var. patens (Col.) Hatch comb. nov.

Pt. patens Col. Trans. N.Z. Inst. 18. 1886. 270.

Cheeseman included Colenso's species in Pt. banksii, but it differs from the typical form in the position of the sepals and the breadth of the leaves as the following table of comparisons shows. The sepalar caudae naturally pass through the horizontal and sub-crect stages in developing from the bud, and transition forms may frequently be found bearing a general resemblance to Pt. banksii proper. Variety patens represents the species in the upper montane and subalpine areas of the North Island, being particularly abundant on the central plateau and extending eastwards over the Kaimanawa Ranges, and south beyond the Ruahines into Hawke's Bay.

patens banksii typica
Dorsal cauda strongly incurved. Dorsal cauda suberect.
Tips of the petals incurved. Tips of the petals horizontal.
Lateral caudae abruptly decurved, the tips meeting behind and below the ovary. Lateral caudae erect, spreading.

Acknowledgments.

The writer is greatly indebted to the Rev. H. M. R. Rupp, of Sydney, for much material and unstinted co-operation over a long period, and to Dr. Gilbert Archey for permission to study the orchid collections in the Auckland Museum. The ready assistance given him in Auckland by Miss B. E. G. Molesworth, and in Dunedin by Mr. George Simpson and Miss E. Campbell is much appreciated.