Carya Nutt. (Juglandaceae)

A genus of about eighteen species of trees; of e. North America (south into s. Mexico), and e. Asia. Carya in our area is separated into two sections, section Apocarya (C. aquatica, C. cordiformis, C. illinoinensis) and section Carya (C. alba, C. carolinae-septentrionalis, C. glabra, C. laciniosa, C. myristiciformis, C. ovalis, C. ovata, C. pallida). The southeastern United States is the center of diversity of Carya.

Eleven species occur in North Carolina, ten of which are considered native to the state.

1. Terminal buds elongate, flattened in cross-section, with 4-6 valvate scales; leaves with 7-13 (-19) leaflets, these symmetrical to strongly falcate; fruit sutures narrowly winged...2.

2. Leaves with 7-9 (-11) leaflets, these symmetrical to slightly falcate; fasciculate trichomes with 2-4 rays; terminal bud, 9-19 mm long, bright orangy yellow to dull orange-tan; [common and widely distributed tree in our area, typically in floodplain and slope forests]...C. cordiformis (Bitternut hickory)

Bark of Carya cordiformis (Copyright W. Cook)

Bark of Carya cordiformis (Copyright W. Cook)

Bark of Carya cordiformis (Copyright W. Cook)

Bark of Carya cordiformis (Copyright W. Cook)

Bark of Carya cordiformis (Copyright W. Cook)

Bark of Carya cordiformis (Copyright W. Cook)

Twig of Carya cordiformis (Copyright W. Cook)

Bud of Carya cordiformis (Copyright W. Cook)

Bud of Carya cordiformis (Copyright W. Cook)

Bud of Carya cordiformis (Copyright W. Cook)

Leaves of Carya cordiformis (Copyright W. Cook)

Leaves of Carya cordiformis (Copyright W. Cook)

Flowers of Carya cordiformis (Copyright W. Cook)

Fruit of Carya cordiformis (Photo A. Krings, CC BY-NC-SA 3.0)

Fruits of Carya cordiformis (Copyright W. Cook)

N.C. distribution of Carya cordiformis

U.S. distribution of Carya cordiformis

Carya cordiformis (Bitternut hickory)
(Common; forests and woodlands, especially in rich, moist alluvial or slope forests; Mt, Pd, CP; Fl: Apr, Fr: Oct)

2. Leaves with (7-) 9-19 leaflets, these slightly to strongly falcate; fasciculate trichomes with 2-8 rays; terminal bud {} mm long, brown to rusty-brown...3.

3. Leaves with (7-) 9-11 (-13) leaflets, the lower surfaces pubescent at least along the midrib and in the main vein axils; bark shaggy; lateral petiolules 0-2 mm long; nut flattened and angled in cross-section; kernel bitter; [native, of swamp
forests, primarily in the Coastal Plain]...C. aquatica (Water hickory)

Bark of Carya aquatica (Copyright W. Cook)

Twig of Carya aquatica (coming soon)

Leaves of Carya aquatica (Copyright W. Cook)

Flowers of Carya aquatica (coming soon)

Fruit of Carya aquatica (Copyright W. Cook)

Fruits of Carya aquatica (Copyright W. Cook)

N.C. distribution of Carya aquatica

U.S. distribution of Carya aquatica

Carya aquatica (Water hickory)
(Uncommon; swamp forests, where flooded during the winter months; CP; Fl: Apr-May, Fr: Oct)

3. Leaves with (7-) 11-19 leaflets, the lower surfaces nearly glabrous; bark scaly, with small exfoliating plates; lateral petiolules 0-7 mm long; nut round in cross-section; kernel sweet; [introduced, frequently cultivated, long persistent, and occasionally naturalized] long, glabrous...*C. illinoinensis (Pecan)

Bark of Carya illinoinensis (Copyright W. Cook)

Terminal bud of Carya illinoinensis (Photo: A. Krings, CC BY-NC-SA 3.0)

Axillary bud of Carya illinoinensis (Photo: A. Krings, CC BY-NC-SA 3.0)

Leaves of Carya illinoinensis (Copyright W. Cook)

Leaf margin of Carya illinoinensis (Photo: A. Krings, CC BY-NC-SA 3.0)

Abaxial leaflet surface of Carya illinoinensis (Photo: A. Krings, CC BY-NC-SA 3.0)

Inflorescences of Carya illinoinensis (Copyright W. Cook)

Inflorescences of Carya illinoinensis (Copyright W. Cook)

Inflorescences of Carya illinoinensis (Copyright W. Cook)

Fruits of Carya illinoinensis (Photo: A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya illinoinensis

U.S. distribution of Carya illinoinensis

*Carya illinoinensis (Pecan)
(Rare; persistant around dwellings and in pecan orchards, escaped to suburban woodlands, rural forest edges and floodplains, commonly cultivated; Pd, CP; Fl: Apr-May, Fr: Oct)

1. Terminal buds ovoid, terete in cross-section, with 6-15 imbricate scales; leaves with (3-) 5-9 (-11) leaflets, these symmetrical to slightly falcate; fruit sutures not winged (except C. myristiciformis)...4.

4. Bark shaggy (on large trees separating in segments to a meter in length); leaves with (3-) 5 (-7) leaflets; serrations of the leaflets densely (or only moderately) ciliate when young, most densely so just below the tooth apex, the hairs sloughing with age but leaving a subapical tuft of white trichomes on at least some teeth; fallen foliage turning black...5.

5. Twigs slender, hardened first-year growth or second-year growth 1-3 mm in diameter; terminal bud 6-15 mm long, glabrous to sparsely puberulent (except for ciliate fringe on the scales), reddish-brown (usually turning black on drying); lower surface of leaflets nearly glabrous, except for tufts of trichomes in the main vein axils, and only slightly lepidote with a few, scattered scales, the large peltate scales yellow and round, the small peltate scales brown, 2- and 4-lobed; terminal leaflet 2-5 (-6) cm wide...C. carolinae-septentrionalis (Carolina shagbark hickory)

Bark of Carya carolinae-septentrionalis (Copyright W. Cook)

Bark of Carya carolinae-septentrionalis (Copyright W. Cook)

Bark of Carya carolinae-septentrionalis (Copyright W. Cook)

Twig of Carya carolinae-septentrionalis (coming soon)

Leaves of Carya carolinae-septentrionalis (Copyright W. Cook)

Leaves of Carya carolinae-septentrionalis (Copyright W. Cook)

Flowers of Carya carolinae-septentrionalis (coming soon)

Fruits of Carya carolinae-septentrionalis (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya carolinae-septentrionalis

U.S. distribution of Carya carolinae-septentrionalis

Carya carolinae-septentrionalis (Carolina shagbark hickory)
(Uncommon; upland flats, especially those weathered from mafic rocks and with shrink-swell soils dominated by montmorillonitic clays, less typically on slopes and bottomlands; Pd; Fl: Apr-May, Fr: Oct)

5. Twigs stout, hardened first-year growth or second-year growth (2.5-) 3-6 mm in diameter; terminal bud 9-18 mm long, tomentose, tan to brown (rarely turning black on drying); lower surface of leaflets moderately to densely hirsute with acicular and fasciculate hairs (sometimes the hairs more or less limited to the main veins), and also moderately lepidote, the large peltate scales yellow and round, the small peltate scales dark brown and mostly round; terminal leaflet (4-) 6-15 cm wide...C. ovata (Shagbark hickory)

Bark of Carya ovata (Copyright W. Cook)

Bark of Carya ovata (Copyright W. Cook)

Bud of Carya ovata (Copyright W. Cook)

Leaves of Carya ovata (Copyright W. Cook)

Leaves of Carya ovata (Copyright W. Cook)

Flowers of Carya ovata (Copyright W. Cook)

Flowers of Carya ovata (Copyright W. Cook)

Fruit of Carya ovata (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya ovata

U.S. distribution of Carya ovata

Carya ovata (Shagbark hickory)
(Uncommon; Rich moist bottomlands, slopes, occasionally on dry upland flats; Mt, Pd, CP; Fl: May, Fr: Oct)

4. Bark tight (the ridges typically forming an interlocking diamond pattern), scaly, or shaggy (when shaggy, the separated segments normally much < 1 meter long); leaves with (3-) 5-9 (-11) leaflets; serrations of the leaflets glabrous or ciliate, but lacking subapical tufts of trichomes; fallen foliage not notably blackening...6.

6. Twigs stout; terminal buds 8-20 mm long; leaves with (5-) 7-9 (-11) leaflets; lower surface of leaflets moderately to densely hirsute with a mixture of acicular (single), fascicled (2-8 rays), and multiradiate (8-many rays) hairs; small peltate scales of the lower surface of leaflets all round; fruit husk 4-13 mm thick; nuts slightly to strongly 4-angled toward the apex....7.

7. Bark tight; petiole hirsute; leaflet apex acute; lower surface of leaflets densely hirsute with acicular (single) and abundant 2-8-rayed fascicled and multiradiate hairs; fruit husk glabrous, with pustulate bumps; fruit 3.5-5 cm long; nut 2.5-3.5 cm long; [common in our area]...C. tomentosa (Mockernut hickory)

Bark of Carya tomentosa (Copyright W. Cook)

Bark of Carya tomentosa (Copyright W. Cook)

Twig of Carya tomentosa (coming soon)

Leaves of Carya tomentosa (Copyright W. Cook)

Leaves of Carya tomentosa (Copyright W. Cook)

Flowers of Carya tomentosa (coming soon)

Fruit of Carya tomentosa (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya tomentosa

U.S. distribution of Carya tomentosa

Carya tomentosa (Mockernut hickory)
(Common; forests and woodlands; Mt, Pd, CP; Fl: Apr-May Fr: Oct)

7. Bark shaggy; petiole hirtellous; leaflet apex acuminate; lower surface of leaflets hirsute with acicular (single), 2-6-rayed fascicled, and occasional multiradiate hairs; fruit husk pubescent, lacking pustulate bumps; fruit 4-7 cm long; nut 3-6 cm long; [rare in our area]...C. laciniosa (Kingnut hickory)

Bark of Carya laciniosa (Copyright W. Cook)

Bark of Carya laciniosa (Copyright W. Cook)

Bark of Carya laciniosa (Copyright W. Cook)

Twig of Carya laciniosa (coming soon)

Leaves of Carya laciniosa (Copyright W. Cook)

Flowers of Carya laciniosa (coming soon)

Fruit of Carya laciniosa (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya laciniosa

U.S. distribution of Carya laciniosa

Carya laciniosa (Kingnut hickory)
(Rare; moist, circumneutral, alluvial levee forests along brownwater rivers of the CP, and streams; Pd, CP; Fl: Apr-May, Fr: Oct)

6. Twigs slender; terminal buds 3-15 mm long; leaves with (3-) 5-7 (-9) leaflets; lower surface of leaflets mostly glabrous, except for along the midrib and primary veins, and sometimes hirsute on the surface with acicular (single) and infrequent fascicled (2-8 rays) hairs (lacking multiradiate trichomes); small peltate scales of the lower surface of leaflets of various types, 4-lobed and/or irregular scales often more frequent than round scales; fruit husk 2-5 mm thick; nuts not 4-angled toward the apex...8.

8. Terminal bud 5-15 mm long, predominantly pubescent (also sparsely lepidote); leaves with (3-) 5-7 (-9) leaflets; lower surface of spring leaflets slightly to densely lepidote with irregular and round peltate scales (4-lobed peltate scales uncommon)...9.

9. Fruit husk spitting to base at maturity along 2-4 sutures; leaves with (5-) 7 leaflets, pubescent beneath; petiole reddish; fruits typically ellipsoidal; bark tight or often scaly or somewhat shaggy...C. ovalis (Red hickory)

Bark of Carya ovalis (Copyright W. Cook)

Bud of Carya ovalis (Copyright W. Cook)

Branch of Carya ovalis (Copyright W. Cook)

Leaves of Carya ovalis (Copyright W. Cook)

Leaves of Carya ovalis (Copyright W. Cook)

Leaves of Carya ovalis (Copyright W. Cook)

Flowers of Carya ovalis (coming soon)

Fruit of Carya ovalis (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya ovalis

U.S. distribution of Carya ovalis

Carya ovalis (Red hickory)
(Common; forests and woodlands; Mt, Pd, CP; Fl: Apr-May, Fr: Oct)

9. Fruit husk indehiscent at maturity or tardily splitting to base along 1 suture; leaves with (3-) 5 (-7) leaflets, glabrous to pubescent beneath; petiole usually green; fruits ellipsoidal, pyriform, or subglobose; bark tight...C. glabra (Pignut hickory)

Bark of Carya glabra (Copyright W. Cook)

Bark of Carya glabra (Copyright W. Cook)

Bark of Carya glabra (Copyright W. Cook)

Twig of Carya glabra (coming soon)

Leaves of Carya glabra (Copyright W. Cook)

Leaves of Carya ovalis (Copyright W. Cook)

Leaves of Carya glabra (Copyright W. Cook)

Flowers of Carya glabra (Copyright W. Cook)

Fruit of Carya glabra (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya glabra

U.S. distribution of Carya glabra

Carya glabra (Pignut hickory)
(Common; in a wide variety of forests and woodlands; Mt, Pd, CP; Fl: Apr-May, Fr: Oct)

8. Terminal bud 4-10 mm long, predominantly lepidote (also pubescent); leaves with (5-) 7 (-9) leaflets; lower surface of spring leaflets densely lepidote with 4-lobed, irregular, and round peltate scales, giving the undersurface a reflective, silvery-tan, rusty-brown, or bronze sheen...10.

10. Lepidote scales initially silver, soon turning bronze, and giving the buds, young twigs, and undersurface of the leaves a metallic bronze sheen; fruit 2-3 cm long; [of calcareous swamps, bottomlands and slopes of the Coastal Plain of se. NC southwards]...C. myristiciformis (Nutmeg hickory)

Bark of Carya myristiciformis (Copyright W. Cook)

Bud of Carya myristiciformis (Copyright W. Cook)

Leaves of Carya myristiciformis (Copyright W. Cook)

Leaf of Carya myristiciformis (Copyright W. Cook)

Leaf of Carya myristiciformis (Copyright W. Cook)

Leaves of Carya myristiciformis

Flowers of Carya myristiciformis (coming soon)

Fruit of Carya myristiciformis (Copyright W. Cook)

N.C. distribution of Carya myristiciformis

U.S. distribution of Carya myristiciformis

Carya myristiciformis (Nutmeg hickory)
(Rare; nonriverine swamps over calcareous substrates, including calcareous clays and coquina limestone, oak flatwoods; CP; Fl: Apr, Fr: Oct)

10. Lepidote scales silvery-tan , giving the buds, young twigs, and undersurface of the leaves a dull or slightly shiny tan color; petiole and rachis hirsute with fasciculate trichomes, and also with concentrations of hairs near the leaflet insertions; fruit 3-5 cm long; [usually of upland and acidic forests and woodlands, collectively widespread in our area]....C. pallida (Sand hickory)

Bark of Carya pallida (coming soon)

Rachis of Carya pallida (coming soon)

Rachis of Carya pallida (Copyright W. Cook)

Leaves of Carya pallida (Copyright W. Cook)

Leaves of Carya pallida (Copyright W. Cook)

Leaves of Carya pallida (Copyright W. Cook)

Leaf underside of Carya pallida (Copyright W. Cook)

Flowers of Carya pallida (coming soon)

Fruit of Carya pallida (Photo A. Krings, CC BY-NC-SA 3.0)

N.C. distribution of Carya pallida

U.S. distribution of Carya pallida

Carya pallida (Sand hickory)
(Common; dry sandy or rocky forests and woodlands; Mt, Pd, CP; Fl: Apr-May, Fr: Oct)