The Ecology of the Gorse (Ulex) with Special Reference to the Growth-Forms on Hindhead Common

Fritsch and Salisbury in Further Observations on the Heath Association on Hindhead Common, published in the-New Phytologist in 1915, have paid considerable attention to the growth-forms of Ulex europaeus and Ulex nanus (minor), relating them in part to degree of exposure. At the suggestion of Prof. Fritsch I have endeavoured to follow up this work by anatomical comparisons and further study of the different growth-forms, and by measurements of their transpiration rates. An attempt has also been made to correlate the anatomy and transpiration rate in each case. Most of the work has been done with U. europaeus, which is a common plant of English heaths and of scrub establishing itself on neutral grassland 2. In many places it has the appearance of a comparatively recent invader, and on heaths of diversified topography it favours on the whole the more sheltered situations. It is more abundant and luxuriant in the midlands, south and east of England than in the north and west, where it tends to give place to U. Gallii, especially at higher altitudes. In northern Scotland it is scarce and possibly introduced. In Ireland it is commoner in the east than in the west. On Hindhead Common it is chiefly restricted to the valleys where it skirts the footpaths3. This fact has been noted by other observers, but no explanation other than that given by Weiss 4 concerning the probable distribution of the seeds by ants, which favour footpaths as their tracks, has yet been put forward.