Thelymitra uniflora was first observed on the Auckland Islands by Lieut. Le Guillon, one of
the officers of the French exploring-ships "Astrolabe" and "Zelde," which, under the command
of Admiral D'Urville, visited the Islands in March, 1840.

Le Guillon's specimens were very imperfect; but in November of the same year it was again collected by Sir J. D. Hooker during the Antarctic voyage of Sir J. C. Ross. In

1844 it was published by Hooker in the "Flora Antarctica" under the name it still bears.

It was first gathered in New Zealand proper by Dr. Lyall, at Milford Sound; and shortly afterwards
in eastern Otago by Mr. Buchanan. Since then it has been found to be abundant on the margins
of peaty swamps or on damp, open, elevated moorlands as far north as Rotorua.

It descends to sea-level in Stewart Island and in several localities in the South Island, but is most abundant between 2,000 ft. and 3,500 ft. It is specially plentiful on the Waimarino Plateau, to the west of Tongariro and Ruapehu, where in the month of January every peaty swamp is adorned with its dark-blue flowers.

T. uniflora belongs to Lindley's section Biaurella, in which the column-wing does not extend behind the anther, but has two prominent erect lateral lobes. In T. uniflora these lobes are more or less spirally involute, as shown in figs. 1 and 2 of the accompanying plate, and are sometimes connected by a crest at the back of the anther (see fig. 2). Its nearest ally is undoubtedly the Tasmanian T. cyanea, if, indeed, the two plants are not identical.

Prasophyllum Colensoi, as its name indicates, was one of the many discoveries made by Mr.
Colenso, but I am not aware of the exact habitat in which it was first found. This, however, is not
of any great importance, seeing that it is now known to extend from the North Cape to Antipodes Island, and to be one of the most abundant orchids in subalpine moorlands.

Whether the form so generally distributed in mountain districts at elevations ranging from 2,000 ft. to 5,000 ft., and which must be taken as the type of the species, is quite the same as that which is sparsely found in lowland situations, and which extends to the extreme north of the Dominion, is not quite certain. The question cannot be settled until a detailed comparison of fresh specimens has been made.

P. Colensoi belongs to the typical section of the genus, called by Bentham: Euprasophyllum, in which the lip is sessile at the base of the column. The only other species of the section found in New Zealand is the Australian P. patens, which differs in its much greater size, larger paler flowers, and longer lip, which has a much larger recurved lamina, the adnate plate not extending almost to the tip, as it does in P. Colensoi (see fig. 8 of the accompanying plate).

The nearest ally of P. Colensoi, however, is probably the Tasmanian plant described by R. Brown under the name of P. alpinum, but which Bentham, in the "Flora Australiensis," merges with
P. fuscum.

The genus Prasophyllum contains about thirty-five species. Of these, thirty-two are found in Australia (including Tasmania), four in New Zealand, two of which are apparently identical with Australian species, and one (P. calopterum, Rchb. f.) in New Caledonia.