BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Eragrostis curvula | Weeping Lovegrass 



GENERAL BOTANICAL CHARACTERISTICS : 
Weeping lovegrass is an introduced, perennial, warm-season, densely
tufted bunchgrass [2,30,36].  It is a C-4 carbon fixer [56].  Culms can
be pith-filled to hollow; they are erect [23] and 24 to 60 inches
(60-150 cm) tall [29,30,50].  Leaves are primarily basal [42] and
abundant [56].  Culm leaves are 8 to 12 inches (20-30 cm) long [27,50];
basal leaves can be much longer [23,27,30,42, 50].  The inflorescence is
a panicle 4 to 16 inches (10-40 cm) long [23,42].  Spikelets are five-
to twelve-flowered [22,50]; the lemma is unawned [50,56].  The fruit is
a caryopsis [23].  Weeping lovegrass has an extensive fibrous root
system [56].


RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Weeping lovegrass reproduces by seeds; it does not have rhizomes or
stolons [2].  Apomixis is facultative [55].  The seedstalks produce
approximately 300 to 1,000 seeds per head [39].  Rate of spread by seeds
is slow under the best conditions [2].  In most places weeping lovegrass
does not actively colonize adjacent nonplanted sites [10].

Seed dormancy is broken after 5 to 6 months in storage [56].  Time to
initial germination in a laboratory test was 50 to 52 hours [19].  Best
field germination occurs with year-old seed; most seeds germinate in 7
days under favorable conditions [56].  Rainfall pattern is important for
successful weeping lovegrass seedling emergence.  Less than 20 percent
of germinated weeping lovegrass seeds survived 1 day of desiccation
after germination.  No weeping lovegrass seeds survived 3 days of
desiccation [19].  If the soil is dry, adequate moisture within 4 to 7
days after emergence is necessary for seedling survival [12].  Seedlings
are vigorous under favorable conditions [47].  Weeping lovegrass can
make good cover the first year after seeding.  With good moisture
conditions some plants head out the first year [56].

Weeping lovegrass produces tillers which grow outward from the edge of
the clump.  Dead stems prevent production of new tillers to the inside.
After a few years without grazing or burning, the only live shoots in
the decadent plant are in an outside ring enclosing dead material [12].


SITE CHARACTERISTICS : 
Weeping lovegrass grows on dry to moist sites [15] in pastures [50],
fields [42], roadsides [23,27], and disturbed areas [23,50,61]. 

Weeping lovegrass grows and produces well on a wide variety of soils.
It grows well on low fertility soils, but it does best on fertile soils
[12].  It is best adapted to and most persistent on sandy and sandy loam
soils [2,10,12].  It is not well adapted to clayey, salty, or wet soils
[1,12].  Silty loam, clay, and clayey loam soils reduce or inhibit
germination, seedling emergence, shoot growth, and root growth [10].
Weeping lovegrass was tested on the High Plains of western Texas on
three soil types.  Growth was rated good on sandy soil, fair on silty
soil, and poor on clayey soil [13].  In the Santa Cruz Basin in
southeastern Arizona, weeping lovegrass established poorly on silty clay
loam.  However, weeping lovegrass seeds sown in sandy to sandy loam
upland soils germinated and produced plants that persisted for at least
15 years [11].  Weeping lovegrass requires a 150- to 180-day summer
growing season to spread on sandy soils [10].

Weeping lovegrass does well on acid soils in the southeastern United
States [12,18].  Lower pH limit is usually considered to be 4.0, but it
has grown well on some minesoils with pH 3.8 [54].  Weeping lovegrass
also grows on highly basic soils.  It will grow on soils of pH 8.0, but
severe chlorosis usually occurs as the growing season progresses [12].

Weeping lovegrass is adapted to summer rainfall [12].  Established
stands persist where annual rainfall varies from 15.7 to 39.4 inches
(400-1,000 mm) [10].  In critical rainfall areas occasional prolonged
droughts may kill well-established stands [12].  Plant production
declines where summer rainfall exceeds 29.5 inches (750 mm) because of
fungal infections, mites, nematodes, and interference from forbs and
other grasses [10].

Established stands of weeping lovegrass persist where mean minimum and
maximum temperatures vary annually from 32 to 86 degrees Fahrenheit (0-
30 deg C) [10].  Weeping lovegrass does not tolerate extended periods of
temperatures below 14 degrees Fahrenheit (-10 deg C) [50].

Weeping lovegrass has been reported at the following elevations:

                        Feet              Meters

  Arizona           4,921-6,500        1,500-1,981  [4,32,38]
  Colorado             5,000              1,524     [15]
  Oklahoma          1,975-2,300          602-701    [47]
  Texas                3,281              1,000     [44]
  West Virginia     below 3,000        below 914    [54]

Weeping lovegrass persistence in western Oklahoma and northwestern and
north-central Texas is limited to elevations from 984 to 3,281 feet
(300-1,000 m) [10].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Weeping lovegrass can establish in disturbed areas and also persist in
open grasslands.

During the 1940's and 1950's, upland mesas at the Appleton-Whittell
Research Sanctuary in Santa Cruz County, Arizona, were seeded with
weeping lovegrass and Lehmann lovegrass.  In 1984, these mesas remained
dominated by the exotic lovegrasses.  Nearby unseeded areas supported
native perennial grasses, forbs, and shrubs [4].

Basal cover and production of seeded weeping lovegrass in east-central
Arizona tended to be inversely proportional to turbinella oak cover.
Turbinella oak in chapparal was burned by wildfire in 1952.  Where
turbinella oak canopy was reduced less than 50 percent, weeping
lovegrass cover remained approximately the same over 3 postfire years.
Where turbinella oak cover was reduced more than 50 percent, basal cover
of weeping lovegrass increased "markedly" over the 3 years observed [40].


SEASONAL DEVELOPMENT : 
An established weeping lovegrass plant begins growth in spring when mean
minimum temperatures rise above 50 degrees Fahrenheit (10 deg C).
Productivity peaks when mean minimum and maximum temperatures range
between 59 and 86 degrees Fahrenheit (15 and 30 deg C).  Growth declines
in mid-summer when mean maximum temperatures exceed 86 degrees
Fahrenheit (30 deg C) and soils dry [10].  Weeping lovegrass growing
season in northwest Oklahoma is March to November [47].

Tillering begins 4 to 6 weeks after a seed germinates.  Under favorable
conditions several hundred closely packed culms are produced the first
year [39].

Weeping lovegrass susceptibility to frost increases if there is a rapid
temperature drop when the grass is growing.  Injury is also likely
during severe cold coupled with dry soil.  Fall growth initiated by
rainfall, irrigation, fertilization, or grazing seems to predispose
weeping lovegrass to freeze damage [12].

Weeping lovegrass flowering times are:

     California               August-October     [36]             
     Florida                  April-May          [8]
     South Carolina           May-June           [42]
     Great Plains             May-August         [23]   
     Southern Great Plains    late spring and    [56]
                                late summer

Related categories for Species: Eragrostis curvula | Weeping Lovegrass