New Zealand is well isolated from other lands, and particularly from those with high and extensive mountain systems. These mountainous areas support some 500 species which do not extend to the lowlands.
The main diversity is in the South Island, but alpine vegetation is found throughout the North Island mountain chain and isolated patches occur in the Coromandel Range.
Composites are important in the alpine vegetation, and pride of place is taken by Celmisia, a predominantly herbaceous genus, of which there are some 58 species in New Zealand and one in Australia. In C. coriacea the lanceolate leaves are in large tufts, with a silvery pellicle and may be 60 cm long. At the other extreme the leaves of C. laricifolia are tiny and needlelike. Other composites are Helichrysum, Leucogenes (native edelweiss), Haastia, and Raoulia (vegetable sheep).
The largest genus of the Scrophulariaceae in New Zealand is Hebe, which is well represented at high altitudes. Particularly interesting are the “whipcord” Hebes with leaves reduced almost to scales – H. lycopodioides and H. cupressoides. Ourisia and Euphrasia contribute attractive species to the alpine vegetation. Other prominent genera are Gentiana and Ranunculus, the latter having an important centre of evolution in New Zealand. Most striking is R. lyallii of the Southern Alps with peltate leaves up to 24 cm in diameter and large inflorescences of white flowers.