On the floral mechanism of welwitschia mirabilis (Hooker)

Abstract

The present paper is the outcome of a suggestion of Prof. Seward that the details of the flowers of Welwitschia might be with advantage considered from the standpoint of methods which have been found serviceable in the case of the floral mechanisms of Angiosperms. The spirit material used in the investigation was also kindly supplied by Prof. Seward, and was part of some material collected by Prof. Pearson in 1907. As a plant of unique vegetative habit, producing flowers also unique among existing Gymnosperms , Welwitschia requires no introduction to the botanical student; and, since the time of its original description by Hooker (1864), numerous observers have given an account of its special features, chiefly from anatomical or cytological points of view, the most important of these being Pearson’s last contribution to the study of the process of fertilisation (Pearson, ‘Phil. Trans.,' B, 1908).