BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Asimina triloba | Pawpaw 



GENERAL BOTANICAL CHARACTERISTICS : 
Pawpaw is a native, deciduous, large shrub or small tree.  It exhibits
clonal growth, forming thickets or small colonies [15,27].  It grows
from 20 to 40 feet (6-12 m) tall [2,16,31].  There is usually a single
trunk [28].  The bark is thin with shallow, irregular fissures [28].
Young twigs are hairy [12].  Pawpaw leaves can be up to 1 foot (30 cm)
long, and are odorous when bruised [17].  The fruit is a large berry
[15,31].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 

Vegetative reproduction by root suckering is the most important method
of pawpaw regeneration [22].  Rogstad and others [25] reported a
relatively high level of genetic variation among populations, but
moderate or no variation within populations.  This was attributed to the
formation of clonal thickets and/or inbreeding in small populations [25].

Pawpaw reproduces sexually, however, the rate of fruit set is very low
(0.45 percent) compared to the number of flowers produced [33].  It is
pollinated by flies or nitidulid beetles [22,32,33].  It
self-pollinates, but outcrossing is more common [20].  Germination of
pawpaw seeds is slow, probably due to embryo dormancy [2].


SITE CHARACTERISTICS : 
Pawpaw is found in deciduous forests, on slopes of ravines, along
streams, and floodplains.  Soils on which it occurs are usually deep,
rich, damp, sandy, or clayey [15,28,36].

Common tree associates include blackgum (Nyssa sylvatica), Ohio buckeye
(Aesculus glabra), honey locust (Gleditsia triacanthus), and coffee tree
(Gymnocladus dioica) [3,9].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Pawpaw is tolerant of shade, but appears to die out in old-growth
forests.  In southwestern Pennsylvania, moderate numbers of pawpaw
seedlings and saplings were found in mature second-growth forests, but
none were found in undisturbed, old-growth forests [7].  

From a compilation of historical records and current data on its
distribution, Campbell [3] concluded that pawpaw is suited to regimes of
moderate disturbance.  Pawpaw is a good competitor when undisturbed for
a period of time, but does not spread into either early- or
late-successional forest types [3].


SEASONAL DEVELOPMENT : 
Pawpaw flowers emerge with the leaves, from February to May, depending
on latitude [8,28].  Fruits ripen from July to September [17].

Related categories for Species: Asimina triloba | Pawpaw