BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Maclura pomifera | Osage-Orange 



GENERAL BOTANICAL CHARACTERISTICS : 
Osage-orange is a small, native, deciduous tree that averages 30 feet (9
m) in height.  It has a short trunk and rounded crown.  Shade-killed
lower branches remain on the tree for years, forming a dense thicket.
Branches growing in full sun have sharp, stout thorns 0.5 to 1 inch
(1.3-2.5 cm) long.  Osage-orange has a large, round multiple fruit
composed of many fleshy calyces, each containing one seed.  Osage-orange
generally has a well-developed taproot; a tree in Oklahoma had roots
more than 27 feet (8.2 m) deep.  On shallow soils, roots spread
laterally [4,7,34].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Osage-orange reproduces vegetatively and by seed.  It is dioecious.
Female trees begin producing seeds at age 10 but are most productive
from age 25 to 65.  Good seed crops are produced nearly every year.
Seeds are disseminated by animals, gravity, and water.  Seeds have a
slight dormancy which is overcome by soaking in water for 2 days or
stratifying in sand or peat for 30 days.  Seed germination requires
exposed mineral soil and full light.  At 7 years of age, osage-orange is
about 8 feet (2.4 m) tall with a crown spread of about 6 feet (1.8 m)
[2,4,40].

Seed collection, cleaning, storage, and planting techniques are
described [2,34].

Osage-orange sprouts vigorously from the stump [4,34].  Godfrey [7]
suggested that it also sprouts from the roots.


SITE CHARACTERISTICS : 
Osage-orange grows best in areas that receive 25 to 40 inches (640-1,020
mm) precipitation a year but tolerates a minimum of 15 inches (380 mm).
It is sensitive to cold and succumbs to winter-kill in the northern
Great Plains [4,34].

Osage-orange grows on a variety of soils but does best on rich, moist,
well-drained bottomlands.  It occurs on alkaline soils, shallow soils
overlaying limestone, clayey soils, and sandy soils [4,26,35].  It can
occur on bottomlands which are seasonally flooded [4].


SUCCESSIONAL STATUS : 
The shade tolerance of osage-orange is not well defined.  It has been
listed as intermediate in tolerance [32] and intolerant [4].
Osage-orange grows in the subcanopy of bottomland forests [4,16], but it
also invades overgrazed pastures and other open, disturbed sites with
eroding soil.  Osage-orange regenerates naturally on sunny sites but
grows when planted in dense hedges [4].

Osage-orange in remnant bottomland hardwood forests is negatively
associated with fragment size.  In other words, the smaller the area of
remnant forest, the more likely that osage-orange will occur there.
Rudis [23] suggested that fragmentation may promote and accelerate the
establishment of pioneer species and species adapted to disturbance.


SEASONAL DEVELOPMENT : 
Osage-orange generally flowers from April to June and the fruit ripens
from September to October [2,4].  It flowers in mid-May in Kansas and
Nebraska [28].

Related categories for Species: Maclura pomifera | Osage-Orange