Common Name: Bitternut

General Information

Carya cordiformis is a deciduous tree that can grow up to 52 metres tall. In forest conditions the trunk is typically long, straight and branch-free, with a short crown of ascending branches[].
The plant is harvested from the wild for local use as a food, though the seed id generally bitter and little eaten, even by wildlife[]. It is a traditional source of medicines and materials, and produces a useful woods.. It is grown as an ornamental and shade-providing tree.[]
Carya cordiformis has a large, stable known population which is found across an extensive range, with no known major threats.The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2018)[].

Known Hazards

None known

Botanical References

, ,

Range

Eastern and southeastern N. America - Ontario and Quebec and south to Texas and Florida.

Habitat

Better-drained hillsides and limestone glades, low wet to dry woods, flood plains, stream banks and borders of swamps[, ], tolerating a range of soils; at elevations up to 900 metres[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Slow
Pollinators	Wind
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Carya cordiformis has a wide native range and is tolerant of a range of climates. It is found where the mean annual precipitation ranges from 640 - 1,270mm, with most of that falling in the growing season. In the north of its range it can experiences around 2030mm of snow per year. Annual temperatures range from about 4 - 18°c, July temperatures from about 18 - 27°c, and January temperatures from -15° to 12° c. Extremes of plus 46°c down to -40°c have occurred within the range. The plant seldom grows in areas where the growing season is less than 120 or more than 240 days long[].
Prefers a deep moisture-retentive loam in a sunny sheltered position. Plants require a good, hot summer for best development and fruit production[, , , , ]. Slow growing[].
This is the hardiest and best growing member of this genus in Britain[], unfortunately the seed is generally bitter[]. However, a couple of edible varieties have still been developed ('Hatch' and a thin-shelled form 'Halesite'), though we have no details on levels of bitterness[, ].
This species is a prolific producer of root suckers and coppice shoots from the root crown of felled trees[].
Hybridizes in the wild with Carya illinoinensis[]. Hybridizes with other members of this genus[].
Plants are strongly tap-rooted and should be planted in their permanent positions as soon as possible[, ]. Sowing in situ would be the best method so long as the seed could be protected from mice[, ].
Plants in this genus are notably resistant to honey fungus[].
Most species in this genus have quite a wide range of distribution and, in order to find trees more suited to this country, seed from the most appropriate provenances should be sought[]. Most trees growing in Britain at present tend to only produce good seed after hot summers[].
Trees are self-fertile but larger crops of better quality seeds are produced if cross-pollination takes place[].

Edible Uses

Seed - raw or cooked[, ]. Thin shelled but bitter and astringent[, ]. Even squirrels tend to pass it over[]. The seed is about 25 - 40mm long[, ]. The seed ripens in late autumn and, when stored in its shell in a cool place, will keep for at least 6 months[].

Medicinal

The oil from the seeds has been used in the treatment of rheumatism[].

The bark is diuretic and laxative[].

Agroforestry Uses:

he deep lateral roots of this species make it a valuable tree for watershed protection[].
Trees are late coming into leaf (usually in late spring to early summer) and they lose their leaves early in the autumn (usually in October)[]. Whilst in leaf they cast a heavy shade. These factors combine to make the trees eminently suitable for a mixed woodland planting with shrubs and other trees beneath them[].

Other Uses

An oil expressed from the seeds has been used as an illuminant in oil lamps[]. Mixed with grease, it is rubbed into the skin to deter mosquitos[].

The fibrous bark is used to make chairs[].

Often used as a potted stock plant for grafting varieties of pecans (Carya illinoensis)[].

Wood - heavy, very hard, strong, elastic, tough, close grained[, , ]. It weighs 47lb per cubic foot[]. Although the wood tends to be brittle, it has an amazing quality of shock-resistance and is used for hoops, tool handles etc, though it is considered to be inferior to other hickories[, , ].
A very good fuel, burning well and giving off a lot of heat[]. The wood makes a good quality charcoal[].

Propagation

Seed - requires a period of cold stratification. It is best sown in a cold frame as soon as it is ripe[]. Stored seed should be kept moist (but not wet) prior to sowing and should be sown in a cold frame as soon as possible[]. Where possible, sow 1 or 2 seeds only in each deep pot and thin to the best seedling. If you need to transplant the seedlings, then do this as soon as they are large enough to handle, once more using deep pots to accommodate the tap root. Put the plants into their permanent positions as soon as possible, preferably in their first summer, and give them some protection from the cold for at least the first winter[, ]. Seed can also be sown in situ so long as protection is given from mice etc and the seed is given some protection from cold[] (a plastic bottle with the top and bottom removed and a wire mesh top fitted to keep the mice out is ideal)