Carya Fruits (hickory nuts)

Compare features of Carya (hickory) species
Key to southeastern U.S. Carya (hickory) species

Hickory fruits consist of hard-shelled nuts, surrounded by a woody husk. The husk varies among species as to how easily it splits and whether the sutures are winged along part or all of their length. The nuts are edible, although they vary in size and taste. Carya illinoinensis (pecan) and C. laciniosa (kingnut) are the largest and taste the best, whereas C. cordiformis (bitternut hickory) and C. glabra (pignut hickory) taste bad. The image below compares the fruits of common southeastern US hickory (Carya) species. Click on the image to view it at a larger size.

Individual Carya fruits. Click on an image for a larger view. Written descriptions from: Chester EW, RJ Jensen, LJ Schibig, S. Simoni. 1987. The Nut Trees of Land Between The Lakes. The Center for Field Biology of Land Between The Lakes, Austin Peay University, Clarksville, TN

Carya carolinae-septentrionalis (southern shagbark hickory): often broader than high, 2 to 4 cm wide; the husk 3 to 9 mm thick, splitting freely to near the base; nut ovoid, prominently four-angled, with a thin shell; kernel light brown and sweet.

Carya cordiformis (bitternut hickory): 2 to 4 cm long, rounded, four-winged from the apex to the middle; the husk thin, covered with small yellow scales; nut often broader than long; shell thin; kernel red-brown and very bitter.

Carya glabra (pignut hickory): approximately 2.5 cm long and 2 cm wide, pear-shaped (narrows at the base); husk thin, dark brown, only slightly splitting into segments if at all; nuts broadest near the apex, narrowed at the base; thick shell; kernel insipid or bitter.

"wild" (upper) and cultivated (lower)
pecan

Carya illinoinensis (pecan): 3.8 to 5 cm long, oblong, in clusters of 3 to 6; husk thin, narrowly four-winged, dark brown, hairy; nut elongate, rounded at the base and pointed at the tip, brown; shell thin; kernel oily and sweet.

Carya laciniosa (shellbark hickory or kingnut hickory): the largest of any hickory [in the area], 4.5 to 6.5 cm long and 3.8 cm broad, occurring singly or in pairs; thick husk splitting readily into segments when ripe; nut flattened, ridged; shell very thick and hard; kernel sweet.

Carya ovalis (red hickory): 2.5 to 3 cm long and about 2 cm wide; husk thin, about 2 to 2.5 mm thick, splitting freely to the base; nut with ridges extending from 1/3 to 1/2 its length; shell thin; kernel small and sweet.

Carya ovata (shagbark hickory): occurring in pairs or solitary; large, slightly longer than wide, 3 to 5 cm long; the dark brown to black, moderately thick husk splitting freely to the base when ripe; nut longer than wide, flattened, usually four angled, light-colored, with a thin shell; kernel sweet.

Carya palida (sand hickory): small, 13 to 37 mm long, somewhat rounded, slightly longer than broad, covered with short hairs and yellow scales; husk thin, 3 to 4 mm thick and splitting tardily to the base by 2 or 3 sutures; nut laterally flattened, ridged, light-colored; shell very thin, 2 to 3 mm thick; kernel sweet.

Carya tomentosa (mockernut hickory): 3.8 to 5 cm long; husk 3 to 6 mm thick, splitting nearly to the base when ripe; nut with thick shell and sweet kernel.