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Woody > Carya > Carya cordiformis > Carya cordiformis

Carya cordiformis

Bitternut Hickory

Origin:  The Bitternut Hickory is a native tree with a widespread habitat in North America
Tree (deciduous)
USDA Hardiness Zone
4b – 8b
Canadian Hardiness Zone
2a – 6b
RHS Hardiness Zone
Temperature (°C)
30- 40
Temperature (°F)
(-22)- 104
18-25 m
8-10 m
Description and Growing Information
Flowering Period
Ornamental specimen, shade tree and woodland gardens.
As a sapling, it can tolerate shaded areas, but as it matures it will require full sun. The Bitternut enjoys moist sandy loam, but can also tolerate drought conditions in other soil textures. It grows well between a pH of 4.8 to 7.4. Unlike other Hickories, it is less susceptible to frost damage; but still requires at least 17 weeks of frost free days in a season to flourish.
ID Characteristic
The most identifiable characteristic is the sulphuric yellow buds. However, the buds are not visible during the spring and summer, in which case you can identify it by the 3 branched male catkins (pollen sacs) hanging in clusters throughout the canopy and the ‘Heart shaped’ nuts.
Grows in moist mountain valleys, along streams. Usually found in wetlands, but it is very adaptable and can grow in dry areas with poor soils.
Bark/Stem Description
When young, the bark has a greenish-grey hue with a smooth texture. As the tree ages, the bark becomes fairly recognizable; developing shallow interlacing ridges, with whitish lines within them. The ridges may also form a vertical twisting-like character up the trunk. The trunk will grow to roughly 1 m in diameter. The bark smoothens out, gradually, from trunk to limb tips. It will also not develop exfoliating bark like that of the Shagbark or Shellbark Hickories.
Flower/Leaf Bud Description
The buds of this tree are sulphur yellow in colour, velvety or granular, comprised of 3 or more overlapping scales, reaching lengths roughly 20 mm long. Again, this feature is the most distinguishable of the Bitternut.
Leaf Description
The leaf formation is alternate and pinnately compound. Leaflets are sickle shaped, 15-20 cm long, with 7 to 11 blades. The upper leaf surface is primarily dark green throughout spring and summer; while the bottom is a lighter green in colour, and exhibiting grey to rusty brown scales. The canopy in autumn, turns into a picturesque chartreuse; however, concluding a strong growing season, leaves turn a beautiful bright golden yellow.
Flower Description
Just like all Hickories, flower production is monoecious; meaning the tree contains both male and female flowers at the same time. Flowering usually occurs from April to May. The catkins hang from the previous years twig growth. While female flowering pistillate occur at the apical meristematic growth of the current year’s growth. The male pollen spreads by wind attaching to the pistillate flowers.
Fruit Description
The fruit is a small, 1.5 to 3 cm, greenish brown, husk covered nut. The look is said to be heart shaped, but really more rounded. With 4 very definitively raised seams wrapping around the outer husk. The fruit ripens from September to October, and is fully dispersed from the tree before December.
Notable Specimens
Medway Valley Heritage Forest, London, Ontario, Canada. The Sawyer Preservation Woodlot, Kirkton, Ontario, Canada. The Royal Botanical Gardens, Burlington, Ontario, Canada.
Propagation of the Bitternut is achieved by sowing the seeds. The seeds do however require stratification, cooling the seed for germination. Germination requires a time of anywhere from 90 to 120 days. In other methods, transplanting is attempted. This tree is one of the most successfully transplanted in all the Hickory lineage. It does however take the tree about 30 years before it will start producing seeds. With its optimal production being from roughly 50 years old until it’s 125 years old.
Ethnobotanical Uses (Disclaimer)
Native Americans would make their bows, handle tools and wheels from this wood. The wood is strong and highly shock absorbing. The nut was processed into oil for lamps.