Aria. In winter, specimens of cultivated Sorbus fennica show the following characters represented in Plate 45:—
Twigs: long shoots glabrous, shining, dark brown, with a few scattered lenticels. Leaf-scar crescentic, very narrow, set obliquely on a reddish brown, slightly projecting cushion; it shows a varying number of bundle traces,[1] 3, 4, or 5, and may thus be distinguished from other species of Sorbus, as Pyrus Aucuparia has 5 dots on the scar, while Pyrus Aria, intermedia, and latifolia have only 3. Terminal bud large, conic, tomentose, especially at the apex. Lateral buds small, either appressed to the stem or diverging from it at an acute angle. Bud-scales few, densely pubescent on the outer surface, and ciliate in margin. Short shoots ringed, pubescent, bearing a terminal bud.[2]
Distribution
The form fennica occurs plentifully in Scandinavia, where it grows wild, reproducing itself naturally by seed, and behaving as a true species. It extends in Norway, according to Schübeler, up to lat. 66° 14' on the west coast as a wild plant, and in Sweden up to 60° wild and 62" planted; it also occurs in Finland, but is not recorded from other parts of Russian territory. In Central Europe it only occurs sporadically, and apparently always in company with the parent species; it is recorded from various mountain stations in France, Switzerland, Germany, and Austria.
The hybrids which occur in the Isle of Arran have attracted much attention and discussion. Formerly it was believed that Pyrus Aucuparia, Pyrus intermedia (var. scandica), and Pyrus fennica, all occurred in a wild state. Koehne,[3] however, considers that (excepting Aucuparia) all the plants in question on the island are hybrids, there being two sets, one typical fennica, while the other set comprises forms between that and scandica. This view, which excludes one of the parents (viz. scandica), implies that these hybrids, once established, may under favourable conditions reproduce themselves naturally and behave generally as true species.
N.E. Brown says of this species that it is "rare and perhaps not indigenous except in Scotland"; but he has seen specimens from Kent, Sussex, Hants, Somerset, Gloucester, Leicester, Stafford, Cumberland, Roxburgh, Arran, and Dumbarton. He thinks that Arran seems to be the only truly native locality for this tree in the British Isles, and believes that the Arran plant placed under intermedia is a form of it. Watson, however, states in his Compendium, p. 510, that Borrer held it to be wild in North Hants between Farnham and Farnborough, where it was observed sparingly along with Aria and Aucuparia, both more plentifully. A specimen picked by James M'Nab in Darenth Wood, Kent, is, according to Watson, identical with Arran specimens.
There is a fine tree on the edge of a shrubbery close to Wilton House, Wilts, the seat of the Earl of Pembroke, about 50 feet by 5.
- ↑ If the dots are not plainly visible externally, they can be seen clearly on paring off the epidermis of the scar.
- ↑ The twigs in winter described above clearly show the hybrid origin of this species; the varying number of dots on the scar, the pubescence and shape of the scales, etc. show the influence of Pyrus Aucuparia.
- ↑ Koehne, Jour. of Bot. 1897, p. 99. See also Rev. Dr. Landsborough's account of the Arran hybrids in Trans. Bot. Soc. Edin. xxi. 56 (1897).
