Page:TheTreesOfGreatBritainAndIreland vol01.djvu/196

168 resembles Pyrus Aria. It is of hybrid origin, one parent being either that species or Pyrus intermedia, while the other is Pyrus Chamæmespilus. It is distinguished from Pyrus Aria by the larger and more irregular teeth of the leaves (cf. Plate 44), and its flowers are pinkish white, borne in loose corymbs. Various intermediate forms have been distinguished, as—

Sorbus ambigua, Michalet. Exactly intermediate between Pyrus Aria and Pyrus Chamæmespilus, with the leaves larger than in the second, and smaller than in the first, and the margins having a tendency to lobing. Tomentum whitish.

Sorbus arioides, Michalet. A form intermediate between ambigua and Aria.

Chamæmespilus x Mougeoti. Leaf large, with lobes well marked and rounded; tomentum greyish. These hybrids are common in the Jura and the Alps.

The whitebeam is a wide-spread species. It occurs throughout Europe generally, reaching in Norway as far north as lat. 63° 52', and in Sweden to lat. 59°. It is met with also in Algeria, Asia Minor, the Caucasus, Armenia, Siberia, and Central China, assuming in some of these regions remarkable varietal forms. It is replaced in the Himalayas and Japan by Pyrus lanata, Don, an allied species.

While it occurs on all soils except those which are wet, it has a decided preference for limestone. In woods and hedges it grows to be a small tree; but in exposed situations on rocky mountains, etc. it dwindles to a mere bush. On the Alps it ascends to 4800 feet

In the British Isles its distribution has not been accurately made out, as many supposed records refer rather to intermedia or latifolia. Apparently, however, as a wild tree, the typical form is almost entirely confined to the southern and midland counties of England and to south Wales. Variety rupicola is recorded from nearly every county from Devon to Sutherland, and is widely spread on the littoral range between Lancaster and Humphrey Head, ascending in Banffshire to 1200 or 1400 feet, where it has been found by Dr. Shoolbred of Chepstow on limestone cliffs near Inchrory in upper Banffshire. In Ireland the whitebeam is rare and local, and both the type and rupicola occur.

By far the finest specimen that we know of in England or elsewhere grows on the edge of Camp Wood, near Henley on Thames, on Sir Walter Phillimore's property, where Henry saw it in 1905. It measures 75 feet high by 4 feet 9 inches in girth, with a bole about 35 feet long, and has very smooth beech-like bark (Plate 51).

There is a large and very well shaped tree at Walcot, Shropshire, which in 1906 Elwes found to be 56 feet high and 6½ feet in girth, with a clean bole about 20 feet long.