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Volume 77, 1948-49
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Aporostylis R. and Hh., Townsonia Cheesmn., and the New Zealand Forms of Chiloglottis R. Br.

[Read before the Auckland Institute, February 19, 1947; received by the Editor, March 18, 1947; issued separately, February, 1949.]

Aporostylis.

Historical. This species was originally collected by Hooker in the in the Flora Antarctica. Later, in the Flora Novae Zealandiae, he named it Caladenia bifolia, noted that the upper leaf was apparently developed from the stem bract that is normal in Caladenia, and considered this fact sufficient to warrant the retention of the species in that genus. In 1864 Baron von Mueller recorded it from the Chatham Islands, and referred it to Chiloglottis as Ch. traversii. In the addendum to the 1864 Handbook (p. 741), Hooker quoted Mueller's observations and agreed with him that there was much reason for not including the species in Caladenia, but pointed out that it could be hardly included in Chiloglottis without a modification of the generic character, and suggested that such revision be carried out. This was eventually done by Schlechter, and the plant became Ch. bifolia. New Zealand workers, however, followed Hooker's nomenclature, and in all subsequent literature the word “anomalous” was freely used. In 1944 the Rev. H. M. R. Rupp, of Sydney, suggested to the writer that a new genus be erected to accommodate this troublesome plant, since it fitted into neither Caladenia nor Chiloglottis, and to include it in either was to strain unduly the generic meaning. So Aporostylis came into being.

Aporostylis Rupp and Hatch.

Description. A monotypic genus confined to New Zealand and the outlying islands. It's affinities with Caladenia and with Chiloglottis are obvious, yet the character of the column separates it from both. It may have originated as an intergeneric hybrid between early forms of these two genera. The description of the species is also that of the genus.

Aporostylis bifolia (Hook. f.) Rupp and Hatch. Proc. Linn. Soc. N.S.W., 70, 1945, 61.

Orch. No. 5, Hook. f., Fl. Ant., 1, 1844, 70.

Caladenia bifolia Hook. f., Fl. Nov. Zel., 1, 1853, 247.

C. macrophylla Col., Trans. N.Z. Inst., 27, 1895, 896.

Chiloplottis traversii F. v. M., Veg. Chath. Is., 1864, 51.

Ch. bifolia (Hook. f.) Schltr., Engl. Bot. Jahrb., 45, 1911, 383.

A terrestial herb with small globular tubers. Exceedingly variable, up to 25 cm. high. Pubescent, hirsute or glabrous. Surface bract prominent, broad, acuminate, stem bracts absent. Leaves 2, often equal, but the lower usually larger, broad-linear to almost

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Fig. 1—Aporostylis bifolia, natural size. a, flower from the side; b, labellum from above; c, column from side; d, column from front.
Fig. 2—Townsonia viridis, × 2. e, labellum, column and petals from front; f, ditto from side.

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Fig. 1—Chiloglottis cornuta, natural size. a, flower from side; b, flower from front; c, column and labellum from side; d, seeding plant (reduced).
Fig. 2—Chiloglottis formicifera, natural size. e, flower from side; f, column from front; g, column from side; h, labellum from above; j, labellum from side, (e–j after Fitzgerald.)

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orbicular, up to 15 cm. long by 4 cm. broad, mucronate or the upper often acute. Floral bract loosely sheathing, acute. Flowers 1–2, white or pink. Dorsal sepal erect, broad-lanceolate, acute or obtuse. Lateral sepals broad-linear, acute. Petals narrow-linear, acute. Labellum sessile, ovate, with rounded apex and entire margins, subpetaloid with 2 irregular linear calli near the base. Lamina usually with dark blotches. Column spotted at the base, resembling that of Chioglottis but with the wings neither lobed nor produced behind the anther.

The habit is usually subrosulate and the leaves ovate-orbicular, but when growing in a tall sub-association the leaves tend to become erect and are much longer and narrower. With maturity the elongation of the stem causes the upper leaf to rise away from the lower.

Aporostylis is almost certainly self-fertile.

Distribution. Endemic—4, 5, 6, 7, 10, 11, 12a, 13, 14, 15, 16, Chathams and Auckland Islands. Subalpine areas throughout both main islands, descending to sea level in Stewart and the outlying islands.

Sea-level-4,500 ft. Flowers January, small groups or scattered.

Townsonia.

Historical. First discovered by a Mr. Gunn near the foot of Mount Wellington (Tasmania) in October, 1839, this plant was referred to Acianthus by Hooker in the Flora Tasmaniae. It was discovered on Mount Rochfort, near Westport (New Zealand) by W. Townson in 1904 and used as the type of the genus Townsonia by Cheeseman in 1906. In 1911 Schlechter transferred the Tasmanian plant to Townsonia, leaving the genus with two supposed species. H. M. R. Rupp (Vict. Natr., 50, 1933, 18, t.) published a careful analysis of the Tasmanian and New Zealand forms and came to the conclusion that the two were identical. In 1944 the writer confirmed Rupp's conclusions from a study of dried material. Later, living material became available from Stewart Island, proving beyond doubt that there was only one species in Townsonia.

Townsonia Cheesmn.

Description. A monotypic genus occurring in Tasmania and New Zealand. It appears to occupy the same position in relation to Acianthus as does Adenochilus to Caladenia. It probably originated in Tasmania as an offshoot of Acianthus and has been windborne to New Zealand. Another theory, originally propounded by Schlechter, suggests that Townsonia arose in the paleozelanic subantarctic areas and drifted northward along two routes into Tasmania and New Zealand. The description of the species is also that of the genus.

Townsonia viridis (Hook. f.) Schltr. Fedde. Repert., 9, 1911, 249.

T. deflexa Cheesmn., Manl. N.Z. Ft., 1906, 602.

Acianthus viridis Hook, f., Fl. Tasm., 2, 1860, 372.

Slender terrestrial herbs. Root of creeping, jointed, fleshy caudicles with small globular tubers arising from the joints. Leaves up to 8, independent of the flowering stem, arising from the caudicle on long petioles, ovate-orbicular, apiculate, repand. Flowering stem up to 18 cm. high. Stem bract rather high, foliaceous, sessile. Floral

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bracts sheathing, subacute. Flowers up to 4, superficially resembling Acianthus, small, green, erect in the bud, afterwards becoming horizontal and eventually deflexed. Dorsal sepal cumulate, broad, obtuse or subacute. Lateral sepals linear-lanceolate, obtuse, with inrolled margins. Petals minute, erect. Labellum clawed, shorter than the lateral sepals, ovate-concave, obtuse, the centre darker than the margins. Sensitive, normally lying along the lateral sepals, but on being touched springs up against the column, entirely covering it. Column shorter than the (erect) labellum. Column-wings broad, descending to the base. Stigma large, high on the column. Rostellum very small, between stigma and anther. Anther terminal, erect, 2–celled. Pollinia free, pollen granular.

Distribution. Australia—Tasmania, mountain gullies, very rare. New Zealand—10, Mounts Rochfort, Frederick and Paparoa, 11, 1904 et subseq., W. Townson; 14, Resolution Is. (Dusky Sound), W. A. Thomson; 16, Mount Anglem, 11, 1946, E. Willa.*

Sea-level-2,500 ft. Flowers Nov.-Dec., small groups in mossy scrub. It is worth noting that in the original Westport localities the plant was found growing in association with Olearia colensoi Hook. f. This same apparent partnership also occurs in Stewart Island. Nothing is known of the pollination of the species, but the mobile labellum suggests that insects may play a part. Smith's illustration (Cheeseman, Illus. N.Z. Fl., 2, 1914, t. 198b) may be regarded as the hypotype of the species.

Chiloglottis.

Chiloglottis R. Br.

Description. Small terrestrial herbs with ovoid or globular tubers. Leaves 1–3, subrosulate. Flowers 1–2, almost sessile, or pedunculate. Stem elongating considerably after fertilisation of the ovary. Dorsal sepal erect or incurved, more or less clawed. Lateral sepals and petals variously lanceolate. Labellum undivided, sessile, clawed. Lamina with variously arranged prominent calli. Column long, slender, narrowly winged. Column-wings lobed at the top, but not produced behind the anther. Stigma orbicular, high on the column. Rostellum between stigma and anther. Anther terminal, erect, 2–celled. Pollinia 4, pollen granular.

An Australian genus of 7 species, 2 of them extending to New Zealand, probably windborne originally across the Tasman. Hybrids are frequent among the Australian forms, but since New Zealand has only one species widespread, such crossing does not occur. The species are extremely susceptible to epharmony.

Key.

Plant robust, flower almost sessile cornuta
Plant very slender, flower on a long peduncle formioifera.

[Footnote] * Since writing the above Townsonia has been discovered for the first time in the North Island. (5, Mt. Ruapehu—on the Ohakune Track—12, 1947, O. E. Gibson). Mr. Gibson sent living plants which compare exactly with the Stewart Island specimens illustrated here.

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Chiloglottis cornuta Hook. f., Fl. Ant., 1, 1844, 69.

Ch. muelleri R. D. Fitzg., Austr. Orch., 2, 1885, 2.

First collected by Lyall on Campbell Island in December, 1840, this plant was not found on the mainland until 1870, when it was collected by Kirk at Northcote, near Auckland. It was united with the Australian Ch. muelleri in 1945. (Rupp and Hatch, Proc. Linn. Soc. N.S.W., 70, 1945, 57.)

A stout, glabrous herb up to 13 cm. high. Leaves 1–3, subrosulate, petiolate, oblong-lanceolate, acute, conspicuously reticulated. Floral bract foliaceous or bracteate. Flowers 1–2, greenish-purple. Dorsal sepal broadly ovate-lanceolate, erect, acuminate. Lateral sepals usually deflexed, linear-lanceolate. Petals broader, spreading. Labellum triangular-cordate, acute or obtuse, more or less concave. Lamina with several large, dark, irregular calli. Column incurved, wings with 2 lobes produced above the anther. Stigma large, orbicular, concave. Seeding peduncle up to 28 cm.

Distribution. Australia—Tasmania, Victoria, not common. New Zealand—frequent throughout both main islands, Stewart, Chatham, Auckland, Campbell, and Antipodes Islands.

Sea-level-3,500 ft. Flowers Oct.-Jan., small colonies or scattered, on the forest floor. Ch. cornuta is largely pollinated by insects, but is capable of self-fertilisation should the former method fail.

Chiloglottis formicifera R. D. Fitzg., Austr. Orch., 2, 1885, 2.

Slender, up to 8 cm. high. Leaves 1–2, subrosulate, sessile, oblong-lanceolate, obtuse, margins finely undulate. Flowering peduncle up to 7 cm. high. Floral bract narrow-acute. Flower solitary, greenish. Dorsal sepal erect, linear-spathulate, acuminate. Lateral sepals linear, acuminate. Petals broader, abruptly deflexed or almost erect. Labellum on a long narrow claw with an expanded rhomboid lamina, the margin rounded or acute. Calli numerous, in 2 groups, the posterior large, more or less insectiform, the anterior small, more regular. Column wings broader than in Ch. cornuta, column otherwise similar. Seeding peduncle up to 12 cm. high.

Distribution. Australia—New South Wales, rather rare, confined to the coastal area. New Zealand—2, Kaitaia, 9, 1900, et subseq., R. H. Matthews.

Nothing is known of the method of pollination. Fitzgerald's illustration in the Australian Orchids may be regarded as the hypotype of the species.

In all but one case the descriptions and illustrations have been drawn from living material examined by the writer. Ch. formicifera was drawn from a dried New Zealand specimen and the dissections taken from the hypotype. The description was taken in Australia from living material.

The writer is greatly indebted to Mr. Cedric Smith and Mrs. Eileen Willa, of Stewart Island, for living specimens of Aporostylis and Townsonia respectively.