BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Rhus typhina | Staghorn Sumac 



GENERAL BOTANICAL CHARACTERISTICS : 
Staghorn sumac is a native, deciduous tall shrub or small tree growing
up to 40 feet (13.7 m) in height [3,16].  The trunk is usually short,
dividing frequently to form ascending branches [6].  Younger branches,
petioles, and leaf-rachis are densely and softly hirsute [16].  Each
leaf is composed of 9 to 29 leaflets that are lanceolate to narrowly
oblong, 2 to 4.7 inches (5-12 cm) long [12,16].  Leaves are only
produced on new branch segments; old branches do not bear leaves [7].
The fruit is a drupe 0.08 to 0.2 inch (2-5 mm) broad, covered with long,
spreading, red hairs, in dense, cone-shaped clusters [8,9,12].  The bark
is thin and nearly smooth, but sometimes peels off in layers [4].



RAUNKIAER LIFE FORM : 
   Phanerophyte
   Geophyte


REGENERATION PROCESSES : 
Sexual reproduction:  Staghorn sumac generally produces at least some
seed every year [3].  Over the 4 years of a phenology study in West
Virginia, there were no staghorn sumac crop failures.  The author rated
staghorn sumac as one of the most consistent seed bearers [31].
Colonies that produce seed do so in abundance [26].  Seeds exhibit
dormancy, probably as a result of hard, impermeable seedcoats [3].
Staghorn sumac seeds were present (intact) in the buried seedbank of an
oldfield site in Virginia [37].  However, staghorn sumac probably
invades new areas via bird-dispersed seed rather than from the seedbank
[1,15].  Germination of staghorn sumac seeds is enhanced by acid
scarification or hot water treatment [3].  In a greenhouse study on the
effects of the amount and kinds of litter on seed germination, it was
reported that the amount, type, or relative composition of litter
(needlelike vs. lamellar leaves) did not significantly affect the number
of staghorn sumac seedlings that emerged [32].

Vegetative reproduction:  Staghorn sumac forms large, dense colonies via
root sprouts [6,40].  This appears to be the mode of reproduction that
results in the largest number of stems; the colonies usually originate,
however, from a single seed [27,29].  Staghorn sumac is dioecious, and
large, single-sexed clumps of stems can form [26].  Within female clumps
within a staghorn sumac population there was a greater incidence of dead
and vegetative trunks than within male clumps (the clumps were assumed
to be clones) [7].  Female trunks, however, grow at the same rate as
male trunks.  Female trunks within a clone may draw on the resources of
other, nonfruiting trunks to which they are linked by underground
connections [7].

Root sprout production in staghorn sumac is apparently stimulated by
top-damage; large numbers of sprouts emerged from staghorn sumac
colonies that were top-damaged by frost in Kentucky [27].


SITE CHARACTERISTICS : 
Staghorn sumac occurs on dry, rocky or gravelly soils, in old fields,
clearings, roadsides, forest edges, and open woods [6,33,40,44].

Staghorn sumac is found at elevations ranging from 100 to 2,000 feet
(30-610 m) in the Adirondack Mountains, New York [44], and at elevations
up to 4,900 feet (1500 m) in the Appalachians [8].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Staghorn sumac is not tolerant of shade.  In Massachusetts its
occurrence in woodlands is associated with irregular open canopies
and/or sites in or adjacent to light gaps [2].  It is a common invader
of recently abandoned fields [15,24].

Staghorn sumac clone interiors can reduce light intensity up to 90
percent.  This creates a situation where new staghorn sumac stems from
root sprouts are unlikely to thrive, and where ground-layer herbs are
also inhibited.  Only shade-tolerant species are able to colonize dense
staghorn sumac thickets [27].  In Michigan a staghorn sumac colony came
to dominate two oldfield sites that had thick ground-layer perennials
including quackgrass (Elytrigia repens).  As staghorn sumac stems
matured and the canopy closed, ground-layer species decreased.  At this
point (7-10 years after abandonment) numerous tree species began to
invade the site.  Of the 13 species observed, 9 tended to establish
under staghorn sumac cover and overall hardwood seedling density was
highest under staghorn sumac cover.  It was hypothesized by the authors
that staghorn sumac facilitates succession by reducing the amount of
ground cover, thus allowing tree seedlings to establish [42].

On roadbank sites in northern Kentucky, staghorn sumac reduced the
growth of crownvetch (Coronilla varis) and tall fescue (Festuca
arundinacea).  These sites were subsequently invaded by Amur honeysuckle
(Lonicera maackii), but not other tree species.  The authors acknowledge
that succession on sites as highly disturbed as roadside embankments is
not likely to be a good model for oldfield or other types of secondary
succession [28].


SEASONAL DEVELOPMENT : 
Staghorn sumac flowers from May to July, depending on latitude [8,16].
The fruits are usually ripe by September and persist on the tree through
the winter [6,17,31,44].

Related categories for Species: Rhus typhina | Staghorn Sumac