Clone from IR-2, Prosser, Washington. Prosser obtained from Kienholtz in Hood River, Oregon in 1970. American and British authors have generally attributed the origin of Beurre Bosc to Belgium, on the assumption that it is the variety introduced by Van Mons as Calabase Bosc in 1807. The descriptions of Calabase Bosc given by European authors however, in no way agree with the characteristics of the pear now recognized as Bosc or Beurre Bosc in England and America. More likely, the present day Bosc pear of America and English pomology is the variety described by Leroy (3) under the name Beurre Bosc. This sort is obviously of French origin, having been named in honor of Louis Bosc, the eminent French horticulturalist. Calabase Bosc, on the other hand, was named by Van Mons after the French naturalist, M. Bosc, no relative of Louis Bosc. Fruit medium or larger in size, acute-obovate-pyriform with long tapering neck. Skin usually deep yellow but at times greenish n color, covered with russet which varies in intensity and character depending upon climatic and cultural conditions. Very attractive when deep yellow in color with russeting smooth and well distributed. Flesh yellowish white, some grit at the center, butter but not melting, very juicy. Rich vinous, aromatic flavor, rates among the best in dessert quality when properly grown. Usually does not ripen at low temperatures and may die in cold storage while still hard and green in color. Mid-season. Tree vigorous, upright, spreading, productive, difficult to shape during formative years but well shaped and stately in maturity. Quite susceptible to fire blight. -- H. Hartman, Oregon Ag. Experiment Station, 1957.
Bosc. Synonyms: Beurre Bosc, Beurre d'Apremont, Beurre de Yelle, Bosc's Flaschenbirne, Bosc's Haschenbirne, Bosc's Thascherbirne, Bose's Beurre, Bose's Early Gourdshaped Pear, Calebasse Bosc, Calebasse passe Bosc, Cannelle, Humboldt's Butterbirne, Marianne Nouvelle. -- W.H. Ragan, Nomenclature of the Pear, 1908.
Beurre Bosc (of Robert Thompson, 1842). Calabasse Bosc, Marianne Nouvelle, Bosc's Flaschenbirne, Beurre d'Yelle (of some). The Beurre Bosc is a pear to which we give our unqualified praise. It is large, handsome, a regular bearer, always perfect, and of the highest flavor. It bears singly, and not in clusters, looking as if thinned on the tree, whence it is always of fine size. It was raised in 1807 by Van Mons, and named Calebasse Bosc in honour of M. Bosc, a distinguished Belgian cultivator. Having also been received at the garden of the Horticultural Society of London under the name of Beurre Bosc, Mr. Thompson thought it best to retain this name, as less likely to lead to a confusion with the Calebasse, a distinct fruit. The tree grows vigorously; shoots long, brownish olive. Fruit large, pyriform, a little uneven, tapering long and gradually into the stalk. Skin pretty smooth, dark yellow, a good deal covered with streaks and dots of cinnamon russet,and slightly touched with red on one side. Stalk one to two inches long, rather slender, curved. Calyx short, set in a very shallow basin. Flesh white, melting, very buttery, with a rich, delicious and slightly perfumed flavour. Ripens gradually, from the last of September to the last of October. -- A.J. Downing, The fruits and fruit trees of America, 1846.