Plate 193.— THELYMITRA UNIFLOKA and 

 PHASOPHVLLUM COLENSOI. 



Family ORCHIDACK^.] ["Genera THELYMITRA, Forst., and 



PRASOPHYLLUM, R. Hr. 



Thelymitra uniflora, Hook. /. Fl. Antmct. i. 70; Cheesem. Man. N.Z. Fl. tu2. 



Prasophyllum Colensoi, Hook. /. Fl. Nor. Zel. i, 241 ; Cheesem. Man. N.Z. Fl. 675. 



Thclyinitia iinifiora was first observed on the Auckland Islands by Lieut. 

 Le Guillon, one of the officers of the French exploring-ships " Astrolabe " and 

 " Zelee," which, under the command of Admiral D'Urville, visited the Islands 

 in March, 1840. Le Guillon's specimens were very imperfect; but in Novem- 

 ber 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 after- 

 wards in eastern Otago by Mr. Buchanan. Since then it has been found to 

 l)e 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. vniflora 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 dis- 

 coveries 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 fo)-m 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 situa- 

 tions, 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 

 Evprasop/n/lb/m, m 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. vatens, which differs in its much greater size, larger paler flowers, and longer 

 lip, which has a nuich 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. alpinnm, but which Ben- 

 tham, in the '" Flora Australiensis," merges with P. fuscum, 



