Art. XXXVII.—On the Defoliation of Gaya lyallii, J. E. Baker.

By L. Cockayne, Ph.D.
Communicated by A. H. Cockayne.

[Read before the Wellington Philosophical Society, 2nd November, 1904.]

In a paper published by me some years ago^* in which the seedling form of Gaya lyallii, var. ribifolia, is described I threw grave doubts on the hitherto universally accepted opinion that G. lyallii is an evergreen at below 3,000 ft. and a deciduous tree at and above that altitude. In support of my opinion the behaviour of cultivated plants at almost sea-level of both the typical form and var. ribifolia is cited, as also of young plants grown under frostless and almost frostless conditions. In all these cases the plants were perfectly deciduous. At an altitude of about 2,000 ft., on the outskirts of the Thirteen-mile Bush, situated on the slopes of Big Ben, Gaya lyallii, var. ribifolia, is abundant. Happening to be in the above locality in October, 1903, I paid special attention to the plant under consideration, and found in every instance the trees quite bare of leaves. To place this fact on record I took a photograph of a grove of these trees (Photo No. 348), which has been sent to several of my correspondents.

Gaya lyallii, var. ribifolia, is essentially a plant of the dry eastern mountain region, while G. lyallii occurs in the much wetter western region. It only remains now for some observer to note the behaviour of the western plant at a low level, when in all probability it will also be found to be leafless in the early spring.