Size and shape of fruit.—Of external characters of pears, size is important if several typical specimens can be examined, but is often misleading because under the stress of environment abnormal specimens may be produced. Gradations in size are expressed by the terms large, medium, and small, modified by very, above, and below. Used in connection with size, uniform signifies that the fruit of a variety runs fairly even in the same size.
Shape is the most important character in describing the fruit. It may be used with immature as well as mature specimens. In determining the shape of the fruit, the pear should be held opposite to the eye perpendicular to the diameter from stem to calyx; or the fruit may be cut longitudinally at its widest diameter. The shape of the body of the pear is usually described first, followed by a description of the narrow part bearing the stem, if this neck is prominent enough to be noteworthy. A pear is pyriform when the curve formed by the body and neck is concave; turbinate, or top-shaped, when the body is nearly round with a short neck. The neck may be long or short, distinct or obscure, obtuse or acute. Sheldon is typically turbinate; Beurré d’Anjou, Beurré Bose, and Bartlett are all pyriform.
A graphic record should accompany a description of the fruit to show size and shape. A simple outline drawing serves the purpose.
The stem.—Varying as little as any other character of the pear, the stem is much used in identification. It may be long and slender, as in the Beurré Bose; short and thick, as in Doyenné du Comice; fleshy, as in Louise Bonne de Jersey; clubbed, when enlarged at the end; and lipped when the flesh forms a protuberance under which the stem is inserted. The stems of pears are often set obliquely as in Beurré Clairgeau; or are crooked or curved as in Howell. In a few varieties the stems are channeled. The stems of some pears have distinguishing colors, those of others are pubescent. In some pears, as Souvenir d’Espéren, there are bud-like projections on the stem.
The length of the stem in pears is a reliable diagnostic character only when it is known from what part of the flower-cluster the fruit was developed. For, as a rule, the nearer the flower to the tip of the raceme in the pear, the shorter the stem on the fruit.
Cavity and basin.—The cavity, the depression in which the stem is set, offers several marks which greatly enhance the value of a description of any of the pears. The cavity may be acute or obtuse; shallow, medium, or deep; narrow, medium, or broad; smooth or russeted; furrowed, ribbed, angular, or uniform; or it may be lipped as described under stem. The color of the skin within the cavity is sometimes different from that without, and there may be radiating lines, rays, or streaks.
The basin, the depression in which the calyx is set, is as important as the cavity in classifying pears and is described by the same terms. The furrows in the basin are sometimes indistinct and are then called wavy. The skin around the calyx-lobes may be wrinkled, plaited, folded, or corrugated. Rarely, there are fleshy protuberances about the calyx-lobes called mammiform appendages.
Calyx-lobes.—The withered calyx-lobes persist in some pears and not in others. They persist in European pears, but are deciduous in the edible-fruited Asiatic species. The calyx-lobes may be open, partly open, or closed in varieties of the fruits in which they are persistent. In some varieties the segments are separated at the base; in others, united. The lobes may lie flat on the fruit or may stand erect. When upright, if the tips incline inward the lobes are said to be connivent; if inclined outward, they are reflexed, or divergent. The lobes may be broad or narrow, with tips acute or accuminate.
Characters of the skin.—The skin of all pears offers several most valuable features for classification. Of these characters, color is the most important. Perhaps no character of fruits varies more in accordance with environment than the color, yet the color itself and the way in which it is distributed on the fruit, serve to make this character a fairly safe distinguishing mark for most varieties of pears. The ground-color of pears is the green or yellow-green of chlorophyll, usually with an over-color of tints and shades of yellow or red. The over-color may be laid on in stripes, splashes, or streaks; as a blush; may mottle the surface; or may be a single color, in which case the fruit is said to be self-colored. In nearly all varieties of colored pears, it is not an uncommon anomaly to find trees under some conditions bearing green fruits. Usually, in pears, the color is laid on solidly; very few varieties have striped or splashed fruits.
The skin may be thick or thin, tough or tender. In a few varieties it is relatively free from the flesh, but with most clings tightly. The surface of the skin is often waxy or oily. This character must not be confused with waxen which refers to the glossy appearance of the skin.