BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Andropogon virginicus | Broomsedge Bluestem 



GENERAL BOTANICAL CHARACTERISTICS : 
Broomsedge bluestem is a 2- to 4-foot-tall (0.6-1.2 m), native,
warm-season, perennial bunchgrass that usually grows in rather small
clumps [9,18].  In South Carolina, maximum clump diameter was achieved
in 7 or 8 years, and averaged about 3.5 inches (9 cm); no clumps were
greater than 5.1 inches (13 cm) in diameter [8].  It is easily
distinguished from other bluestems by its slender appearance and
straw-colored leaves and inflorescences [9].


RAUNKIAER LIFE FORM : 
   Geophyte


REGENERATION PROCESSES : 
Broomsedge bluestem's primary mode of reproduction is sexual.  It is a
prolific producer of small seeds that are dispersed by wind and readily
establish on exposed soil.  Each flowering culm may have as many as 50
racemes, and each raceme 8 to 12 spikelets [37].  Germination is
relatively high after cold stratification.  Eighty-four percent of
broomsedge bluestem seeds germinated after 38 days when sown on flats of
field sand and kept indoors [8].  Seedling surivial in the field is
high.  First-year seedlings in North Carolina averaged 5 inches (13 cm)
in height, while 1- and 2-year-old plants averaged 40 inches (100 cm) in
height and 3 inches (7.5 cm) in basal circumference [16].  Flowering
begins when plants are 2 or 3 years old, and continues thereafter
[8,16].


SITE CHARACTERISTICS : 
Broomsedge bluestem grows in a wide variety of open habitats, from
grassland and pastureland to open woodland.  It is especially common in
oldfields, overgrazed pastures, and cut-over Southeastern pinelands, and
along roads and railroad tracks [9,11,25,33].  It is most common on
sandy soils but also grows on a variety of other soil textures [11,18].
It grows well on low-fertility soils, especially those on eroded,
"worn-out" fields [18].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Broomsedge bluestem is a shade-intolerant, seral species.  It invades
abandoned cropland, roadsides, overgrazed range, and logged-over
pinelands.  It is one of the most common invaders of abandoned
agricultural lands and often forms a continuous cover within 4 or 5
years of abandonment [26].  Broomsedge bluestem is relatively
short-lived.  Once established, it depends upon periodic disturbance to
maintain its abundance.

On infertile soils, broomsedge bluestem acts as a long-lived competitor.
Nearly pure stands can persist on soils low in nitrogen or phosphorus as
a result of competition and allelopathy.  Decaying broomsedge bluestem
inhibits the growth of carelessweed (Amaranthus palmeri), Japanese brome
(Bromus japonicus), prairie threeawn (Aristida oligantha), and little
bluestem (Schizachyrium scoparium) [31].


SEASONAL DEVELOPMENT : 
Broomsedge bluestem's vegetative growth begins in the winter or spring
when daytime temperatures average 60 to 65 degrees F (15-18 deg C) [18].
In North Carolina, flower stalks form by September, and seeds ripen by
late October [8,16].  At the end of the growing season, nearly all green
material dies, leaving a large accumulation of standing dead material
[8].

Phenology of broomsedge bluestem near Gainsville, Florida, was as
follows [28]:

flowering - late September to early October
seed dispersal - early October to mid-December
vegetative growth - February and March, June and July
leaves green - March to late November
drying - late November to mid-December
dormancy - January

Related categories for Species: Andropogon virginicus | Broomsedge Bluestem