resemble in foliage certain other genera of Taxaceæ, but are readily distinguishable as follows:—
Taxus.—Branchlets standing irregularly alternate on the branches. Leaves stalked, greenish underneath with no definite bands of stomata. Buds composed of imbricated scales.
Pruminopitys.—Branchlets and leaves as in Taxus, but with valvate bud-scales.
Cephalotaxus.—Branchlets opposite. Leaves like the yew in consistence, but with white bands beneath showing definite lines of stomata.
Torreya.—Branchlets sub-opposite. Leaves rigid and spine-pointed with white bands beneath, showing definite lines of stomata.
Saxegothæa.—Branchlets in whorls, ascending at an angle. Leaves with bases decurrent on the shoots, and with white bands beneath which are narrow and close to the median line.
The genus is widely distributed over large parts of North America, Europe, Algeria, and Asia, and occurs sporadically in the mountains of Sumatra, Celebes, and the Philippines. Seven distinct species have been described, each confined to a definite territory. These species are, however, rather geographical forms, only differing from one another in trivial characters of foliage and habit. The view taken by Sir Joseph Hooker[1] and by Pilger, the latest monographer of the genus, that they only constitute one species is probably correct. Many of the supposed specific distinctions, such as the density of the foliage on the branchlets, the size and form of the leaf, etc., are due in most instances to the influence of soil, shade, and climate. Moreover, in the varieties of the common yew, which are known to have arisen as sports in the wild state or in cultivation, greater differences occur in the characters of habit, foliage, and fruit, than are observable in the so-called species. In the account which follows, the geographical forms will be treated as varieties.
- ↑ Himalayan Journals, ii. 25 (1854), and Student's Flora of Brit. Islands, 369 (1878).
