A tree usually 60 to 80, rarely above 100 ft high in this country, but known occasionally to have exceeded twice that height in the United States; bark of trunk shallowly fissured. Young shoots with a tuft of down extending downwards from each leaf-bundle, much of which soon falls away; winter-buds ovoid, with closely flattened scales. Leaves in fives, mostly falling the third year, 3 to 5 in. long, roughened on the margins, soft bluish green, with lines of white stomata on the inner sides; leaf-sheath about 1⁄2 in. long, soon falling completely away. Cones 5 to 8 in. long, about 1 in. in diameter before opening, cylindrical, tapering at the apex, curved; scales of cones thin, smooth, rounded, 1 to 11⁄4 in. long, half as wide.
Native of eastern N. America, with a very wide range, from Newfoundland west to Ontario and the Lake states, south to the N.E. states of the USA and the Appalachians; introduced before 1705. The common name of ‘Weymouth’ pine does not refer to the town, but to a Lord Weymouth, who is recorded to have planted it largely at Longleat about two hundred years ago. In France, the name has been contracted to ‘Pin du Lord’. This pine has at various times been largely planted both in England and on the Continent, and is, no doubt, a valuable timber tree, especially in sunnier climates than ours, producing a white, easily worked, light timber, very useful for many purposes, but not remarkable for strength. One hundred years ago this tree covered enormous areas in eastern N. America, and was one of the richest assets of the country. Now fine specimens are comparatively scarce there.
It is an ornamental tree for gardens where the soil is not a heavy clay, especially up to its middle age. Unfortunately it is subject to the five-leaf pine blister-rust (Cronartium ribicola), a fungus which has currant as its secondary host. During the eighty years or so since it first appeared most of the finest specimens in the country have succumbed, though it remains a fairly common tree. Until a resistant strain is developed it cannot be recommended for general planting as an ornamental, which is a pity, as it thrives in this country and often produces self-sown seedlings.
Among the larger surviving specimens of Weymouth pine are: Bury Hill, Surrey, pl. 1850, 105 × 93⁄4 ft (1954); Puck Pits, New Forest, 128 × 81⁄2 ft (1969); Nuneham, Oxon, 83 × 10 ft (1966); Fonthill, Wilts, 112 × 11 ft (1965); Ombersley Court, Worcs., 90 × 18 ft at 2 ft (1964); Chatsworth, Derb., 120 × 81⁄2 ft (1971).
var. chiapensis Martinez – Although not in cultivation, and unlikely to thrive in this country, this Mexican variety is mentioned because of its phytogeographical interest. The late Prof. Martinez, who described it in 1940, at first believed that the herbarium specimens he examined must have come from cultivated trees of P. strobus, but further investigation showed that the tree was genuinely wild in a few localities in Chiapas and Oaxaca, and it was later found in other regions, though it is nowhere frequent. From the southernmost stands of P. strobus in the USA it is separated by about 1,500 miles in a direct line. Other tree species of the eastern United States have a similar disjunct distribution, reappearing in similar or identical form in the rain-forests of Mexico, e.g.,Liquidambar styraciflua.
f. nana Hort. – The epithet nana has been used over the past 150 years for various dwarf or slow-growing forms of P. strobus. According to Krüissmann, some of the plants offered as ‘Nana’ at the present time are really ‘Radiata’ (Handb. Nadelgeh. (1970-1), p. 263).
cv. ‘Prostrata’. – Of creeping habit. The original plant arose at the Arnold Arboretum and a propagation was sent to Kew around 1893, where it still grows in the Rock Garden, hanging vertically down the face of a rock. The botanical name P. strobus f. prostrata Fern. & Weatherby is founded on a plant found growing wild in Newfoundland, of similar habit.
cv. ‘Radiata’. – A dwarf shrub wider than high, dense at first but later of open habit; leaves pointing upward or radially spreading, not drooping. A plant in the Arnold Arboretum was 4 ft high, 5 ft wide in 1930 (Hornibrook, Dw. and Sl. Gr. Conif., 2nd Ed., p. 208 and plate).
cv. ‘Umbraculifera’. – a very striking dwarf, short-stemmed variety attaining about 6 ft, with an umbrella-shaped crown and drooping needles (cf. ‘radiata’).