BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Elytrigia repens | Quackgrass 



GENERAL BOTANICAL CHARACTERISTICS : 
Quackgrass is a cool-season, exotic, perennial, rhizomatous graminoid.
Its stems are erect, decumbent, and may reach heights of 1 to 3 feet
(0.3-1 m) but more commonly grow to 0.25 to 1 inch (0.5-2 cm) high
[18,21].  Quackgrass is green to whitish, with hirsute to nonhirsute
leaves and awned or nonawned lemmas [18,26].  Rhizomes can grow 23
inches (60 cm) or more from the main shoot before sending out stems [36]
and grow as deep as 8 inches (20 cm) [26].  Dahlberg [12] described how
to identify seeds of the Agropyron genus to distinguish between
desirable and undesirable species.


RAUNKIAER LIFE FORM : 
   Chamaephyte
   Geophyte


REGENERATION PROCESSES : 
Quackgrass propagates mainly by rhizomes but also reproduces by seed.
Seed production, however, is reported to be as low as 25 viable seeds
per plant per season [36].  Studies in Alaska showed that seed viability
may vary depending on how deep and long the seeds have been buried;
viablity is reduced significantly after burial for 21 months [10].  In
greenhouse trials, dormancy of seeds buried 6 inches (15 cm) deep was 16
percent, while dormancy of seeds buried 0.8 inch (2 cm) deep was only 5
percent [9].  Cross-pollination is necessary for seed production [44].
Dormancy in rhizome buds has been related to nitrogen deficiencies,
which peak in June [8].  Sod mats can be as dense as 367 meters of
rhizomes per square meter [36].


SITE CHARACTERISTICS : 
Quackgrass invades gardens, yards, crop fields, roadsides, ditches, and
just about any disturbed, moist area [21].  It invades mixed-grass
prairies as well as oak (Quercus spp.)-hickory (Carya spp.) and
whitebark pine (Pinus albicaulis) forests [1,24,49].  It can tolerate
some saline conditions in the low-lying valleys of Utah [26].
Salt-tolerant cultivars have been developed by crossing quackgrass with
bluebunch wheatgrass [42].  Elevational range in four western states
follows [14]:

State              Elevation

Utah              5,100-8,200 feet (1,554-2,499 m)
Colorado          4,800-10,000 feet (1,463-3,048 m)
Wyoming           4,500-8,000 feet (1,372-2,438 m)
Montana           5,000-6,600 feet (1,524-2,012 m)

Some associate species of quackgrass include sedge (Carex spp.), bulrush
(Scirpus spp.), rush (Juncus spp.), bluebunch wheatgrass, crested
wheatgrass, red top (Agrostis alba), indiangrass (Sorghastrum nutans),
bluestems (Andropogon spp., Schizachyrium spp.), smooth brome (Bromus
inermis), poverty oatgrass (Danthonia spicata), panic grass (Panicum
spp.), Kentucky bluegrass (Poa pratensis), common ragweed (Ambrosia
artemisiifolia), prairie pepperweed (Lepidium densiflorum), prairie
dropseed (Sporobolus heterolepis), Canada thistle (Cirsium arvense),
Carolina geranium (Geranium carolinianum), and bracken fern (Pteridium
aquilinum) [1,5,11,15,24,26,28].


SUCCESSIONAL STATUS : 
Quackgrass is an early seral dominant in disturbed areas [15,22,27].


SEASONAL DEVELOPMENT : 
Quackgrass flowers from June through August in Colorado, Wyoming, and
Montana; and from June through July in North Dakota [14].

Optimum temperatures for growth are between 68 and 77 degrees Fahrenheit
(20 and 25 deg C), with no growth occurring above 95 degrees Fahrenheit
(35 deg C) or below 35 degrees Fahrenheit (2 deg C) [16,36].  Primary
rhizome growth begins in late May or early June and then again in
September and October [36].  Rhizome growth seems to be favored by low
temperatures [50 deg F(10 deg C)] and long days (18 hours) [36].

Related categories for Species: Elytrigia repens | Quackgrass