16 THE WILTSHIRE ARCHAEOLOGICAL AND NATURAL HISTORY MAGAZINE 
Salix alba (photograph by Joan Davis, 2002) 
old coppice stools also common south of the A4 
road); Holly (Ulex aquifolium, also forming dense 
masses by layering); Elder (Sambucus nigra, which 
even forms epiphytic plants on larger trees by bird- 
sown seedlings); and Field Maple (Acer campestre, a 
common fringe and boundary tree). 
Most Willow species are confined to the 
wetlands south of the A4. White Willow (Salix 
alba) forms dense damp jungles, mainly by 
layering rather than seeding. Over the last fifty 
years, White Willows have been out-competing 
the other common wetland willow, the Crack 
Willow (Salix fragilis) because of disease in the 
latter (see later subheading). The eleven other 
wetland willow (Salix) species and hybrids listed 
are all less common; but one willow/sallow species 
is very common throughout the grounds, and 
spreads by seed rather than (mainly) by layering. 
This is the Goat Willow, also known as Grey 
Sallow, or (for male trees) the Pussy willow (Salix 
caprea). It is common in wooded areas, in wetlands, 
and seeds readily in flowerbeds, edges and waste 
places. 
Continuing the very common species, Wild 
Cherry (Gean, Mazzard, Prunus avium) seeds 
occasionally and also spreads by root suckers. The 
Wild Cherry is a conspicuous boundary feature 
around some of the northern fields, and is in some 
of the copses. The Silver Birch (Betula pendula) 
seeds profusely, forming saplings in central and 
peripheral areas of the College grounds. The last 
two very common tree types, conspicuous because 
of their great size, are Beech and Copper Beech 
(Fagus sylvatica and F. sylvatica ‘Purpurea’). Most 
were originally planted, but seedlings occasionally 
survive to saplings where permitted. 
FURTHER COMMON AND 
CONSPICUOUS LARGE TREES 
1. Conifers 
Nos. 3 and 4, the ten types of Lawson’s Cypress 
(Chamaecyparis lawsonia) are characteristic trees 
near the central parts of the College grounds, and 
near buildings. There is also one peripheral group 
in a line south of the running track pavilion, (west 
of the Preshute White Horse), which line acts as a 
break to the prevailing winds. Many of the older 
Lawson’s Cypresses have begun to layer, including 
the yellow, blue and juvenile-foliaged cultivars. 
There is a scatter of European Larches (Larix 
decidua) throughout the grounds. The Larches at 
the far west end of the Nature Trail have either 
yellow or rich red-purple female ‘flowers’. Norway 
Spruces (Christmas trees, Picea abies) are also 
widely distributed, but with small concentrations 
in the Nature Trail Beechwood to the south, and by 
Field Cottage in Barton Dene to the north of the 
A4. Scots Pines (Pinus sylvestris, pink upper trunks) 
and the two subspecies of Black Pines (Pinus nigra, 
grey trunks) fringe some margins and occur in some 
copses, mainly to the north of the A4. 
No other conifer types are both common and 
conspicuous; and none (apart from Yew, see previous 
section) were seen to produce successful seedlings. 
2. Oaks 
The only common mature Oak species is the 
English Oak (Quercus robur), which is scattered 
north and south of the A4, and mostly 
peripherally, including northern and southern 
boundaries and the Nature Trail to the south-west. 
Natural seedlings and saplings occurred, but some 
mature Q.robur trees were markedly afflicted by 
oak dieback disease (see Tree Diseases sub- 
heading). 
3. Alders and Birches. 
Common Alder (Alnus glutinosa) is common, but 
confined to banks of the River Kennet and its 
tributaries south of the A4 where seedlings and 
saplings can be found. The only common, 
conspicuous and self-perpetuating Birch apart from 
Silver Birch (see previous section) is Downy Birch 
(Betula pubescens, widely scattered with a few big 
trees, and nearly as common as Silver Birch). 
