This section is from the book "Laboratory Manual Of Horticulture", by George W. Hood. Also available from Amazon: Laboratory Manual Of Horticulture.
This list is intended to cover most of the important terms which might be confusing to the student. Several general terms used in describing fruit are listed first, and the remaining terms follow in alphabetical order under the various headings.
Acute. Tapering nearly to a point.
Apex. A term understood as applying to the part most remote from the branch or root. (In pears, this part is usually spoken of as the crown.) Axis. A line connecting the base and the apex.
A longitudinal section of a fruit is made by cutting it from base to apex; a cross, or transverse, section is made by cutting it at right angles to the axis. Base (of a fruit). The portion toward the branch or root. Compressed. With the sides flattened, as in some plums. Depressed. Sunken, as the apex of peaches. Furrowed (of fruit). More or less regularly channeled.
Irregular. A term applied to an outline that is elliptical or angular. Obtuse. Blunt; approximating an obtuse angle. Pit. A term applied to the seed found in drupaceous fruits. Regular. When a section through the equatorial diameter shows nearly a circular outline, the fruit is said to be regular. Ribbed. Having large obtuse and rounded ridges. Symmetrical. Having parts mutually well proportioned; regular. Truncate. Abruptly flattened at the end, or (of fruit) appearing as though cut squarely across.

Fig. 38. A, apex; B, base.
 
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