BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Carya cordiformis | Bitternut Hickory 



GENERAL BOTANICAL CHARACTERISTICS : 
Bitternut hickory is a medium-to-large native, deciduous tree, typically
reaching a height of 60 to 80 feet (18-24 m) [11,13].  Under a forest
canopy, it develops a long branch-free trunk with little taper, and a
short rounded crown of slender ascending branches that broaden the crown
toward the top.  The branchlets are sparse and tend to droop slightly
from the main ascending branches.  The leaves are long and slender
[9,16].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Seed production and dissemination:  Bitternut hickory does not produce
abundant seed until the tree is approximately 30 years old [16].
Optimum seed production extends from 50 to 125 years; trees that are
more than 175 years old seldom produce seed crops.  Good seed crops
appear at 3- to 5-year intervals, with light seed crops borne in the
intervening years.  Bitternut hickory seed is estimated to be from 75 to
85 percent viable.  Seed dissemination is almost entirely by gravity
[26].

Seedling development:  Bitternut hickory is probably more tolerant of a
moist seedbed than other hickories and is the least susceptible to frost
damage.  Germination is hypogeal.  Bitternut hickory seedlings grown in
the open or light shade in the Ohio Valley were 13.3 inches (34 cm) at 4
years; sprouts of 1-year-old seedlings grown on red clay averaged 11
inches (28 cm) [26].

Vegetative reproduction:  Bitternut hickory is the most prolific rootand
stump-sprouter of the northern species of hickories, with sprouts
arising from stumps, root crown, and roots.  Most sprouts from sapling
and pole-size trees are root crown sprouts, while those from
sawtimber-size trees are mostly root sprouts.  Stump sprouts are less
numerous than either root crown sprouts or root suckers [26].


SITE CHARACTERISTICS : 
In the northern parts of its range, bitternut hickory occurs on a
variety of sites [5,14].  It is found on rich, loamy or gravelly soil,
low wet woods, and along borders of streams, but is also found on dry
uplands [31].  In the south, bitternut is more restricted to moist sites
than in the north.  It reaches it largest size on the rich bottomlands
of the lower Ohio River Basin [5].  In the southwestern parts of its
range, bitternut hickory is common on poor, dry, gravelly upland soils.
Bitternut hickory is absent from the mountain forests of northern New
England and New York, and it is not found at the higher elevations in
the Appalachians [25].

Principle tree assoicates are listed under Distribution and Occurrence.
Other commom tree associates include eastern hophornbean (Ostrya
virginiana), butternut (Juglans cinerea), and hackberry (Celtis
occidentalis).  Common understory associates include largeflower
bellwort (Uvularia grandiflora), virginia creeper (Parthenocissus
quinquefolia), wood-nettle (Laportea canadensis), and violets (Viola
spp.) [20,26].


SUCCESSIONAL STATUS : 
Bitternut hickory are generally classified as intolerant of shade but
bitternut hickory seedlings appear to be more tolerant on overflow
bottomlands than most of its associates [26].  Top dieback and
resprouting may occur frequently with each successive shoot attaining a
larger size and developing a stronger root system than its predecessor.
By this process, hickory reproduction gradually accumulates and develops
under moderate canopies, especially on sites dry enough to restrict
reproduction of more tolerant, but more fire- or drought-sensitive
species [7,8,26].


SEASONAL DEVELOPMENT : 
Bitternut hickory flowers in April or May.  The fruit ripens in
September and October and is dispersed from September through December
[3,6]. 

Related categories for Species: Carya cordiformis | Bitternut Hickory