Ranunculus lyallii
Hook f. (Upper photograph)

This handsome flower is often erroneously known as the ‘Mount Cook Lily’. although in fact it belongs to the same genus as the common buttercup. It is a buttercup of grand dimensions with stems up to five feet tall, peculiar, nearly circular leaves up to one foot across and flowers up to three inches in diameter. The photograph was taken at Arthurs Pass and the species occurs elsewhere in moist places on mountains throughout the South Island and in Stewart Island. The pure white of the petals is unusual. Of the 43 native species of Ranunculus in New Zealand only one other species (R. buchananii) has white petals. The remainder are yellow. A few years ago Mr. W. B. Brockie crossed Ranunculus lyallii with the large, yellow-flowered R. insignis and obtained a handsome sterile hybrid with pale-lemon petals.

The genus Ranunculus is one of a number of alpine genera in New Zealand which are strongly represented in the north temperate regions and may have originated there. Other such genera are Gentiana. Epilobium and Myosotis and in these, unlike Ranunculus, white flowers are the rule in New Zealand with few exceptions.

Haastia pulvinaris
Hook f. (Lower photograph)

This is the alpine cushion plant commonly referred to as the ‘vegetable sheep’. Such extreme growth forms are quite common in the New Zealand alpine flora, having evolved independantly in about 19 genera. In many cases, including Haastia pulvinaris, the plant is basically a shrub, profusely branched, with the densely leafy, ultimate twigs pressed together lengthwise so that their tips form a continuous and often very firm surface. In the illustration, the more or less circular areas on the surface of the cushion are the branch tips and these are often so firmly compressed that they assume a hexagonal outline. The leaves are densely woolly, and only those at the surface are living. The interior of the cushion between the branches is filled with the decayed remains of older leaves which form a felty humus with a high water retaining capacity.

Haastia pulvinaris belongs to the Compositae or daisy family and can be found in exposed rocky situations above 4.000 feet on the mountains of Marlborough and adjoining areas of Nelson Province. The photograph was taken on Mount Cupola near the head of the Travers Valley.

In the Andes of South America there is a similar array of cushion plants, but they are quite unrelated to those of New Zealand.

J. W. Dawson

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