× Sorbopyrus auricularis (Kroop) Schneid.
Synonyms: Pyrus auricularis Kroop; P. pollveria L.; P. bollwylleriana DC.
A deciduous tree, 20 to 40 ft high (sometimes 50 to 60 ft), forming a rounded bushy head; young branches more or less covered with loose down. Leaves ovate or oval, 3 to 4 in. long, 2 to 21⁄2 in. wide, pointed, irregularly and coarsely, sometimes doubly toothed, rounded or rather heart-shaped at the base, upper surface covered at first with loose down which falls away as the season advances, lower surface permanently grey-felted; stalk 1 to 11⁄2 in. long, woolly. Flowers white, 3⁄4 to 1 in. across, produced about mid-May in many-flowered corymbs 2 to 3 in. across; anthers rosy red; calyx with its triangular lobes covered with a conspicuous pure white wool. Fruit pear-shaped, 1 to 11⁄4 in. long and wide, red, each on a stalk 1 to 1⁄2 in. long, with sweet, yellowish flesh.
This interesting and remarkable tree is a hybrid between the common whitebeam (Sorbus aria) and the pear (Pyrus communis). It is said to have originated at Bollwyller, in Alsace, and is first mentioned by J. Bauhin in 1619 and figured by him in 1650. For three hundred years it has been propagated by grafts, for it produces very few fertile seeds, and these do not come true. The finest tree recorded in Britain grew at Bramford Hall, Ipswich, which, according to information received from Lady Loraine in 1904, was then over 60 ft high.
cv. ‘Bulbiformis’. – A seedling of the Bollywyller pear, raised at Prague before 1878. Both in its foliage and in the larger fruits it was nearer to Pyrus than is the parent. (× S. auriularis var. bulbiformis (Tatar) Schneid.; P. bollwylleriana var. bulbiformis Tatar).
cv. ‘Malifolia’. – Leaves shorter and comparatively broader than in the type, often roundish oval, not so coarsely toothed, nearly always heart-shaped at the base, not so much felted beneath; flowers larger, 1 to 11⁄2 in. across, fewer on the corymb and with stouter stalks, produced in late April and May. Fruits broadly top-shaped, about 2 in. long and wide, deep yellow when ripe. This interesting and handsome tree, although not so common as the Bollwyller pear, is on the whole more attractive. (Pyrus malifolia Spach; × Sorbopyrus malifolia (Spach) Schneid. sec. Bean; Bollwilleria malifolia (Spach) Zab.).
Spach, who named and described Pyrus malifolia in 1834, said that the original specimen at that time grew in the Ménagerie of the Jardin du Roi at Paris, and was 30 ft or more high. He suggested that it might be a hybrid between × S. auricularis and a garden pear (hence a back-cross) but it is more likely to have been a seedling variation of the Bollwyller pear, as ‘Bulbiformis’ is supposed to be. It should be added that the description given above is made from a tree distributed by the firm of Simon-Louis; their stock may have been of independent origin, but the description agrees in all essentials with that of Spach.
Zabel raised a seedling of the Bollwyller pear at Hannover-Münden which he was convinced was a hybrid between it and an apple. He suggested the same parentage for ‘Malifolia’, but the theory is rather far-fetched.