SUBALPINE SCRUB. 113 
of wide range, but the latter confined to the North-eastern Botanical 
District. To the same family belong also the shrubby groundsels, 
very common plants of the subalpine scrub, such as Senecio elaeagni- 
folius, S. Bidwillii, and S. cassinioides. Traversia baccharoides is 
also a shrubby groundsel, which is confined to the north of the 
South Island, with its southern limit in the north of the Eastern 
Botanical District. 
The heaths are represented in subalpine scrub by various species 
of Dracophyllum and by Archeria Traversii and Gaultheria rupestris, 
the latter to be recognized by its lily-of-the-valley-like flowers, after 
the manner of those of G. oppositifolia of the Volcanic Plateau. 
Dracophyllum Traversii is a magnificent small tree, with smooth, 
naked, brown stems extending candelabra-like from the summit of 
the trunk, and each stem crowned at its extremity with a rosette 
of stiff, reddish leaves, having long-drawn-out points arching down- 
wards ; it occurs both in the subalpine scrub of Westland and in 
the uppermost belt of the subalpine forest. Any one journeying 
over Arthur's Pass can hardly fail to observe this truly remarkable 
small tree. The mountain-flax (Phormium Colensoi), also a plant 
of sea-cliffs, is common in subalpine scrub, as is likewise, in some 
localities, one of the spear-grasses (Aciphylla Colensoi var. maxima), 
a most formidable plant with bayonet-like leaves a yard long 
(fig. 78). Manuka (Leptospermum scoparium) is often a constituent 
of certain subalpine scrubs. On the Longwood Range (Southland) 
it is much in evidence, while on certain Stewart Island mountains 
it forms a scrub of extreme density. 
At the beginning of this chapter it was pointed out that about 
100 of the high-mountain plants descended into the lowlands under 
special circumstances. The conditions under which the more im- 
portant of these are found is where the climate of the lowlands is 
of a subantarctic character—t.e., where there is a considerable per- 
centage of cloudy days in the year, a comparatively cool summer, 
and a good many piercing southerly winds at all seasons. Under 
such conditions peat is readily formed and accumulates, bog and 
semi-bog are abundant, and afford positions which most ordinary 
lowland plants abhor, but in which certain high-mountain species 
can get on excellently. Plants of this character are the common 
donatia (Donatia novae-zelandiae), a cushion-plant of mountain-bogs ; 
Senecio Lyallii, a plant of both boggy ground and the banks of icy- 
8—Plants. 
