Plate 158.— OURISIA SESSILIFOLIA. 



Family SCROPHULARIACEiE.] [Genus OURISIA, Comm. 



Ourisia sessilifolia, Hook. f. Handb. N.Z. Fl. 218 ; Cheesetn. Man. N.Z. Fl. o50. 



Ourisia, which is a genus of between twenty or thirty species, is of particular 

 interest to those engaged in the study of the origin of the New Zealand flora, the 

 home of the genus being in the Andes of South America, where it ranges from 

 New Grenada to the Strait of Magellan. But notwithstanding the distance 

 separating the two countries it has established itself in New Zealand, where at 

 least eight species are known : and a solitary species also occurs in Tasmania. 

 As we cannot suppose that the genus has originated independently in the three 

 countries, it becomes a nice question how to account for its presence in localities 

 separated by such immense distances of ocean. 



Sir Julius von Haast, who was the first to collect so many of the species 

 composing the alpine flora of Canterbury, discovered 0. sessilifolia on Mount 

 Brewster, to the north of Lake Wanaka, in January, 1863. Subsequent botanists 

 have observed it in many localities in the alpine centre of the South Island, from 

 the Kaikoura Mountains on the east and the Paparoa Range on the west, south- 

 wards to the south-west of Otago. It also reappears on the summit of Mount 

 Anglem, Stewart Island. It is a high alpine, and is rarely seen below 4,000 ft. 



In the Mount Cook district 0. sessilifolia is an abundant plant on most of the 

 mountains, forming large patches on the sides of moist sheltered hollows, where it 

 must be covered by a considerable depth of snow in the winter and spring months. 

 In such situations it is associated with other alpine plants, such as Celmisia Hectori, 

 Ranunculus sericophijllus, Caltha novce-zelnndiw, Rostkovia gracilis. Carex pyrenaica, 

 &c. It is most abundant at an altitude of about 5,000 ft., but ascends to quite 

 6,500 ft., and possibly higher. Its habit is peculiar, the lower portion of the stem 

 being creeping and rooting, the leaves being practically bifarious and closely 

 appressed to the surface of the ground. The stout peduncle is often 6 in. in height, 

 and bears numerous large white flowers, which shade into dark violet towards the 

 base. When in full flower it is thus a most charming and attractive plant. 



Almost all the species of Ourisia found in New Zealand are well worth cultiva- 

 tion in gardens, even if a little additional trouble is required to grow them to 

 advantage. The two larger species, 0. macrocarpa and 0. macrophylla. are among 

 the finest herbaceous plants known in New Zealand, and their cultivation does 

 not seem to present any extraordinary difficulties. The late Mr. H. J. Matthews 

 grew both of them to perfection in his garden at Mornington. near Dunedin, 

 together with most of the smaller species, including 0. sessilifolia. 



Plate 1,58. Ourisia sessilifolia, drawn from specimens collected in the Mount Cook district, at 

 an altitude of 5,500 ft. Fig. 1, bract (x 2) ; 2, calyx (x 3) ; .3, hairs from the calyx (x 8) ; 4, corolla 

 laid open (x 3) ; 5 and 6, back and front view of anthers (x 6) ; 7, ovary, with style and stigma (x 4) ; 

 8, transverse section of ovary (x 5). 



