BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Dichanthelium acuminatum | Woolly Panicum 



GENERAL BOTANICAL CHARACTERISTICS : 
Woolly panicum is a native, perennial bunchgrass [8].  It is
polymorphic, having early and late season forms of the same plant.
Vernal culms are tufted, usually unbranched and radiating from the base,
and 6 to 32 inches (15-80 cm) tall [14,17,36].  Early leaf blades are
1.6 to 3.9 inches (4-10 cm) long [21,22]; panicles are pyramidal and 1.2
to 4.7 inches (3-12 cm) long [14,21,24].  Autumnal culms are decumbant
and much-branched, mostly from the middle nodes; they produce dense
fascicles of leaves and inflorescences [19,24].  Fall culm leaf blades
are shorter, narrower, and more crowded than early blades.  Winter
rosette blades are also short, but are relatively broad.  Late panicles
are reduced and often partly enclosed in leaf sheaths [21].  Spikelets
are awnless [4]; the fruit is a caryopsis [36].


RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Woolly panicum reproduces by seeds; it does not have rhizomes or stolons
[17,22].  Vernal panicles are open and produce chasmogamous flowers.
Autumnal panicles are reduced [20] and often are partly enclosed in the
leaf sheaths [17]; these enclosed flowers are self-pollinated [21].

Woolly panicum seeds can be found in the seedbank, but presence of
woolly panicum vegetation does not necessarily correspond to presence in
the seedbank.  In southwestern Ohio, five unburned old-field-deciduous
forest sites were surveyed for vegetational and seedbank presence.
Woolly panicum was present as vegetation and in the seedbank at two
sites, present only as vegetation at two sites, and not present in
either form at one site [37,47,48].

In Harvard Forest at Petersham, Massachusetts, woolly panicum was a
widespread seedbank component in old fields and white pine (Pinus
strobus) stands.  It was not a component of the herbaceous ground cover
at any site [30].


SITE CHARACTERISTICS : 
Woolly panicum occurs in a wide variety of habitats.  It is found in
woodlands [19,24] woodland borders, and recently cleared woodland areas.
It occurs on prairies [22], dunes, seashores [17], and along open
roadsides [20].  It grows along the banks of rivers and lakes [29] and
in marshes, swamps and swales [20].  It is found along the shorelines of
bogs [39], pondcypress (Taxodium distichum) ponds [4], and around
hotsprings [9].

Woolly panicum grows on many soil types.  It occurs on heavy, wet soils
[39], silty loam [2,11,48], sandy loam with high organic content [12],
moist to dry sand [14,20,24,34,46,49], and gravelly, often calcareous
soils [49].  Soils are often acidic [12].  In southern Quebec near
Montreal, woolly panicum grows on fine loamy sand with pH 6.1; the soil
is low in magnesium and very low in calcium and nitrogen [43].

Woolly panicum has been reported from the following elevations:

                      Feet             Meters

    Arizona       4,000-6,500       1,219-1,981     [27]
    California      < 8,531           < 2,600       [23]
    Colorado      3,500-5,500       1,067-1,676     [8,22]
    New York        < 5,348           < 1,630       [51]
    Utah          3,510-7,317       1,070-2,230     [52]
    Mexico           98-9,843          30-3,000     [19]


SUCCESSIONAL STATUS : 
Woolly panicum appears in early secondary succession.  It does not
appear in old-growth forests, but is found in stands of intermediate
age.

In southwestern Ohio, woolly panicum occurred in all but the oldest of a
chronosequence of five unburned old-field-deciduous forest sites; the
sites were surveyed nine times during the 1980 growing season.  Site 1
was an old field abandoned for 2 years and dominated by red clover
(Trifolium pratense).  Site 2 was an old field abandoned for 10 years
and dominated by Canada goldenrod (Solidago canadensis) and meadow
fescue (Festuca pratensis).  Site 3 was an old field abandoned for 50
years and dominated by Canada goldenrod, with white ash (Fraxinus
american) and black cherry (Prunus serotina) providing about 30 percent
canopy cover.  Site 4 was an old field abandoned for 90 years and
dominated by a forest of sugar maple (Acer saccharum) and slippery elm
(Ulmus rubra).  Site 5 was an old-growth American beech (Fagus
grandifolia) and sugar maple dominated forest which was over 200 years
old.  Woolly panicum was present but not common at site 1; its seeds
were present in the seedbank.  It was present in "disturbed" vegetation
at site 2; its seeds were not found in the seedbank.  Woolly panicum was
a common species in "disturbed" vegetation at site 3; its seeds were
found in the seedbank.  It was present but not common at site 4; its
seeds were not found in the seedbank.  Woolly panicum was not present
nor found in the seedbank at site 5 [37,47,78].

In upland oak-pine forest sites in the New Jersey Pine Barrens, woolly
panicum did not occur in the flora but appeared to persist in the
seedbank.  Its persistence was attributed to infrequent local
disturbance [32].

Woolly panicum was found in marshes of a Connecticut River oxbow in
western Massachusetts in 1984, though it had not been present in 1974.
Woolly panicum was found only in the highest and driest areas of the
marshes, at low cover (<0.5%) and frequency (1%).  During high water,
much of the marsh area is flooded.  The appearance and disappearance of
woolly panicum was probably due to variations in water level during the
study period [25].


SEASONAL DEVELOPMENT : 

Woolly panicum produces a basal rosette during autumn and winter.
Primary inflorescences develop and bloom on elongated unbranched culms
that grow from the rosettes early in spring.  Late spring, summer, and
autumn growth of the same culms produces fascicles of short, branched
and rebranched lateral shoots with greatly reduced leaves and lateral
inflorescences which also bloom.  Woolly panicum thus has two main
flowering periods [20].

Woolly panicum flowering times are:

       California                    June-August      [35]
       Florida                       May-September    [4]
       Illinois                      May-October      [34]
       New York                      June-July        [10]
       West Virginia                 June-September   [42]
       Eastern United States         May-November     [14]
       Great Plains                  May-June         [21]
                                       through fall   
       New England                   June-September   [40]
       Southeastern United States    May-August       [36]
       Southern United States        begins           [20]
                                       February-March

Related categories for Species: Dichanthelium acuminatum | Woolly Panicum