Plants of Steppe, Herb- and Fell-Field or related Formations. 189 
d. The species of Raoulia (Compos.). 
The genus Raoulia is endemic; it contains 22 species which are separated 
into the subgenera Zu-Raoulia and Psychrophyton. Fifteen of the species are 
confined to the mountains, the remainder, though also montane or subalpine, 
descend to sea-level. Four species occur in the North Island, one being con- 
fined thereto, but the remainder are found only in the Southern province. 
The species are either patch-(frequently circular) or.cushion-plants, but the 
growth-forms are constructed on the same plan, intermediates between them 
occur and the difference is merely one of degree. There is a central woody 
main stem and a deeply-descending chief root. From near the base of the 
main stem rooting prostrate branches pass offradially. These branch abundantly, 
the branches tending to grow upwards, while frequent branching and con- 
sequent increasing density hinders their horizontal extension. Such closeness 
of growth, shutting off the light, causes the death of all the interior leaves and 
many of the stems, the interspaces becoming filled in the case of the thicker 
cushions with peat from their own decay, and in that of low cushions and 
patches with wind-blown silt &c. According to the relation between horizontal 
spread and vertical growth, "so are patch-plants or cushions produced. The 
leaves are small, generally more or less imbricating and frequently tomentose. 
The ultimate shoots are in some species pressed so closely together that they 
form a hard unyielding surface as in the case of those immense cushions, the 
"vegetable-sheep” (R. eximia, R. Buchanani, R. Goyeni &c.). In these, large 
Quantities of peat accumulate in the interior and the upper branches put forth 
adventitious roots by means of which the plant gets most of its water and salts. 
he species of Raoulia show an epharmonic gradation of forms from 
the rapidly growing silvery mats of R. tenuicaulis, with its open mesophytic 
leaves of seedlings and reversion-shoots, to the highly differentiated, dense, 
woolly masses of the vegetable-sheep‘), denizens of wind-swept and, at times, 
Sun-scorched alpine rocks. 
e. Gentiana corymbifera T. Kirk (Gentianac.). 
G. corymbifera is a noble plant which lights up the rather desolate montane 
and subalpine steppe with its multitudes of large delicate white flowers. From 
the centre of a rosette of short yellowish green leaves rises up a stout, yellowish, 
smooth unbranched peduncle, some 40 cm high, which bears on its summit an 
umbel or cyme ı5 cm or more in diam. of white flowers each 2.2 cm in diam. 
The species is confined to the drier mountains of the Southern botanical province. 
F. Schoenus pauciflorus Hook. f. (Cypera«.). 
Wet or boggy ground in subalpine steppe can be recognized, at quite a 
distance through the presence of Schoenus pauciflorus which bestows a distinct 
teddish hue to the association marking it off from the surrounding grass-tussock. 
!) Haastia pulrinaris, a plant of equally. great dimensions and similar-in growth-form to 
R. eximia is also known as "Vegetable-sheep”. (Plate XLVIH, Fig. 71.) $ eh 
