BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Juglans cinerea | Butternut 



GENERAL BOTANICAL CHARACTERISTICS : 
Butternut is a small to medium-sized tree averaging 40 to 60 feet (12-18
m) in height and 12 to 24 inches (30-60 cm) in d.b.h.  This tree has a
short trunk which is divided into a few ascending limbs with large
spreading, sparsely forked branches.  The smaller branches tend to bend
downwards and then turn up at the ends.  The crown is open, broad,
irregular in outline and rounded at the top.  The root system is
composed of a number of wide-spreading laterals that grow to a
considerable depth.  Usually a taproot develops in deep soils [7,21,24].
Butternut grows fast, especially as a seedling, but usually does not
live longer than 75 years [5,21,24].


RAUNKIAER LIFE FORM : 
   Mesophanerophyte
   Microphanerophyte


REGENERATION PROCESSES : 
Seed production and dispersal:  Commercial seed-bearing age begins at 20
years and is optimum from 30 to 60 years.  Good crops of seed can be
expected every 2 to 3 years.  A high percentage of seeds are sound, but
high seed losses occur due to consumption by birds, insects, and
rodents.  Natural pollination failures often occur due to the lack of
pollinated trees in immediate vicinity [4,24].  Upon ripening, seeds are
dispersed by gravity, squirrels, and other rodents. [9,24].

Vegetative propagation:  Stumps of young butternut trees and saplings
can sprout [4,32].


SITE CHARACTERISTICS : 
Butternut is found most frequently in coves, on stream benches and
terraces, on slopes, in the tallus of rock ledges, and on other sites
with good drainage [20,28].  It is found up to an elevation of 4,900
feet (1,500 m) in the Virginias [27,31].  In addition to those indicated
in the SAF cover type slot (Distribution and occurence), common tree
associates include black walnut (Juglans nigra), hickory (Carya spp.),
and white ash (Fraxinus americana) [1,3,20,21,24,27].


SUCCESSIONAL STATUS : 
Although young trees can tolerate partial shade, butternut must be in
the overstory to thrive and is classified as intolerant to shade and
competition [11].  Like other members of the Junglandaceae family,
butternut produces a substance called juglone, a naphthoquinone that is
selectively toxic to associated vegetation.  Greatest concentrations of
juglone are in root tissue and fruit husks, with lesser amounts in the
leaves, catkins, buds, and inner bark [24].


SEASONAL DEVELOPMENT : 
Butternut flowers from April to June, depending on location.  The fruit
matures in September and October and usually remains on the tree until
after leaf fall [4,12].

Related categories for Species: Juglans cinerea | Butternut