VEGETATION SURVEY OF NORFOLK. 
753 
with a scrub of gorse, bracken, blackthorn, bramble, and briar. 
In Attlebridge it was noted that narrow rabbit runs among the 
bracken were carpeted with Ceratodon purpureus , Brachy- 
thecium albicans, and other heath mosses. 
On Alderford Common, Swannington, the soil is a sandy loam 
to a depth of 18 inches and carries bracken, gorse, and bramble. 
Part consists of a huge ancient chalk pit with an approach to 
calcareous vegetation. Festuca ovina is the dominant grass, 
with Reseda luteola, Carlina vulgaris, Cnicus acaulis, and 
Ophioglossum vulgatum as calcicole plants, the last named 
bordering pools among the debris of the chalk workings. 
Of the dominants in a xerophytic flora, gorse seems the least 
exclusive ; it occurs on dry heaths and roadsides, and with 
J uncus on valley gravels near river level ; on higher levels of 
hill tops and plateaux it is associated with bracken, which 
seems to flourish where the subsoil is soft enough for the 
rhizomes to penetrate. For Calluna and Erica cinerea to 
flourish, peat is necessary, while in addition a high moisture 
content is found where Erica tetralix is abundant. The 
blending of grass and lmg communities is common throughout 
the district, and may be attributed to lack of uniformity in soil 
and subsoil ; alternations of heather, bracken, gorse, and grass 
showing superficially the erratic drift deposits familiar in pit 
sections. A good example of sharply-contrasted types occurs 
on the enclosed heath north of Newton St. Faith’s Common 
(marked x in No. 162), where there is about an acre of turf, 
with bracken towards the east and Calluna on the north, south, 
and west. In August, 1910, this was fenced with hurdles and 
grazed. Samples of earth taken from rabbit burrows showed a 
soft ochreous loam almost free from stones and with very little 
humus. 
Costessey Common represents a link between the grass 
heath with bracken and gorse and the Galluna-Erica heath ; 
for though the conditions do not favour a wide development of 
the latter plants, they are found in some portions of the area. 
