Perennial Ryegrass

Nile region, Oases, Mediterranean region, Egyptian desert and Sinai.

North Africa and temperate Eurasia.

Foodplant / spot causer
pycnidium of Ascochyta coelomycetous anamorph of Ascochyta desmazieri causes spots on live leaf of Lolium perenne

In Great Britain and/or Ireland:
Foodplant / parasite
Blumeria graminis parasitises live Lolium perenne

Plant / resting place / within
puparium of Cerodontha incisa may be found in leaf-mine of Lolium perenne

Foodplant / parasite
Drechslera dematiaceous anamorph of Drechslera andersenii parasitises live Lolium perenne

Foodplant / saprobe
colony of Drechslera dematiaceous anamorph of Drechslera dematioidea is saprobic on dead leaf of Lolium perenne

Foodplant / gall
stroma of Epichlo causes gall of stem of Lolium perenne
Remarks: Other: uncertain

Foodplant / pathogen
long stalked apothecium of Gloeotinia granigena infects and damages fallen seed of Lolium perenne
Remarks: season: 5-7

Foodplant / pathogen
strand of Laetisaria fuciformis infects and damages dying plant of Lolium perenne
Remarks: season: 9-10

Foodplant / parasite
fruitbody of Limonomyces roseipellis parasitises live Lolium perenne
Other: major host/prey

Foodplant / spot causer
immersed, crowded or in rows pycnidium of Pseudoseptoria coelomycetous anamorph of Pseudoseptoria donacis causes spots on sheath of Lolium perenne
Remarks: season: 5-7

Foodplant / parasite
amphigenous, scattered or in patches uredium of Puccinia coronata parasitises live leaf of Lolium perenne
Remarks: season: summer

Foodplant / parasite
linear telium of Puccinia graminis ssp. graminicola parasitises live sheath of Lolium perenne

Foodplant / spot causer
conidiophore of Drechslera dematiaceous anamorph of Pyrenophora lolii causes spots on live leaf of Lolium perenne

Foodplant / spot causer
immersed, thin, subcuticular stromatic plates of Rhynchosporium coelomycetous anamorph of Rhynchosporium secalis causes spots on live sheath of Lolium perenne
Remarks: season: 4-9

Foodplant / spot causer
amphigenous, numerous, black pycnidium of Septoria coelomycetous anamorph of Septoria bromi causes spots on leaf of Lolium perenne

Foodplant / spot causer
Spermospora anamorph of Spermospora lolii causes spots on live leaf of Lolium perenne

Foodplant / pathogen
partly hidden sorus of Tilletia lolii infects and damages live spikelet of Lolium perenne

Foodplant / saprobe
fruitbody of Typhula incarnata is saprobic on dying stem of Lolium perenne

Foodplant / spot causer
long, linear, erumpent sorus of Urocystis agropyri causes spots on live, blistered, ribboned leaf of Lolium perenne

Foodplant / parasite
embedded sorus of Urocystis bolivarii parasitises live culm of Lolium perenne

Foodplant / spot causer
long, linear, erumpent sorus of Ustilago striiformis causes spots on live, blistered leaf of Lolium perenne

This species is extensively cultivated in temperate regions of the world as an excellent forage and lawn grass. It is a variable species, with many cultivars (Perennial Rye Grass).

Perennial Rye-Grass freely hybridizes with other species of Lolium and occasionally with species of Festuca. It is extremely variable, especially in the structure of the inflorescence which may be loosely branched or shortened and much congested. It is extensively cultivated as a lawn, forage or soil-binding grass.

1600-2800 m.

Culm 25-50 cm tall, slender, 1-1.5 mm in diameter. Blades linear, 10-15 cm long, 2-5 mm wide; ligule membranous, tongue-shaped, 1.5-2 mm long; auricles conspicuous. Spike up to 15 cm long. Spikelets 2-10-flowered, rarely up to 14-flowered; up to 10 mm long; lower glume absent; upper glume subcoriaceous, narrowly lanceolate, 8 mm long, 5-nerved; lemmas subequal, usually awnless, chartaceous, broadly lanceolate, 5-nerved, as long as the floret, the lowest 7 mm long; palea oblong, as long as the lemma, 2-keeled, minutely ciliate along keels, apex sinus; anther 3 mm long.

Perennial, turf-forming. Culms tufted, erect or spreading, sometimes prostrate and rooting from lower nodes, 30–90 cm tall, 3–4-noded. Leaf blades soft, 5–20 cm × 3–6 mm, glabrous, young blades folded; auricles to 3 mm; ligule 2–2.5 mm. Raceme stiffly erect, or rarely slightly curved, 10–30 cm; rachis glabrous, smooth, spikelets usually less than their own length apart. Spikelets 0.8–2 cm, florets 5–10, rachilla internodes ca. 1 mm, smooth, glabrous; glume lanceolate, 1/3 as long to subequaling spikelet, 3–9-veined, margins narrowly membranous, apex acute or obtuse; lemmas oblong, herbaceous, 5–9 mm, 5-veined, smooth, apex obtuse to subacute, awnless; palea ciliolate along keels. Caryopsis length more than 3 times width. Fl. and fr. May–Jul. 2n = 14, 28.

Loosely to densely tufted perennial; culms 10-90 cm high, erect or spreading, sometimes prostrate and rooting from the lower nodes, slender. Leaf-blades 5-14(-30) cm long, 2-4(-6) mm wide, folded when young, with or without auricles up to 3 mm long at the base. Spikes straight or slightly curved, 3-30 cm long, stiff, slender to moderately stout, the spikelets usually less than their own length apart but sometimes more widely spaced. Spikelets 5-20 mm long, 3-10 (-14)-flowered; upper glume 3.5-15 mm long, one-third to as long as the spikelet, rarely exceeding it, 3-9-nerved, acute or obtuse; lemmas oblong or oblong-lanceolate, 3.5-9 mm long, smooth, obtuse or subacute, not turgid at maturity, usually awnless but rarely with an awn up to 8 mm long.

N. Africa, Europe, temperate Asia.

Distribution: Pakistan (Baluchistan, Punjab, N.W.F.P & Kashmir); Widespread in Europe, temperate Asia and North Africa; widely introduced elsewhere.

Widely distributed in Europe, North Africa and the temperate regions of Asia.

Fl. & Fr. Per.: May-July.

Meadows, grassy places, moist roadsides. Commonly cultivated in China [Russia; N Africa, Europe].

perennial ryegrass
English ryegrass
crested ryegrass

Cover values in North Dakota are rated as poor for mule deer,
white-tailed deer, and pronghorn; and fair for upland game birds and
waterfowl [9].

More info for the term: cool-season

Perennial ryegrass is an introduced, cool-season bunchgrass that grows
up to 35 inches (90 cm) tall. It has erect culms and short rhizomes.
Perennial ryegrass does not have a creeping growth habit [14,46]. It is
generally short-lived (2 to 3 years) [54].

Perennial ryegrass forms vesicular-arbuscular endomycorrhizal
associations [2].

Native to Eurasia, perennial ryegrass is widely planted in North America
for lawns and has many agricultural uses. It occasionally escapes and
becomes naturalized, mostly in waste places and roadsides
[13,39,40,46,57]. It is found from Newfoundland to Alaska, south to
Virginia and California, occasionally farther south [23]. The most
concentrated agricultural use of perennial ryegrass are in the humid
southeastern United States and the mediterranean and temperate climates
of the Pacific Northwest and California, west of the Cascade Range and
the Sierra Nevada [39,40].

More info for the terms: fire regime, litter, rhizome

As with most perennial grasses, perennial ryegrass is well adapted to
fire. It is top-killed and will sprout quickly from the rhizome. Fire
is beneficial to grass swards; by removing litter, it allows more light
to penetrate to the leaf bases and new tillers [59].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

More info for the terms: seed, tiller

Fields of perennial ryegrass grown for seed are usually burned to
control blind-seed disease, remove crop residues, improve herbicide
effectiveness, and stimulate reproductive tiller initiation. For
effective burning, it is important to ensure that crop residues are
fairly evenly distributed, since hot spots can be lethal to underground
rhizomes [14,20].

More info on this topic.

More info for the terms: geophyte, hemicryptophyte

Hemicryptophyte
Geophyte

More info for the terms: facultative wetland species, frequency

Perennial ryegrass is adapted to a wide range of soil types and drainage
conditions and can be grown successfully on earth structures such as
dams and dikes, in grass waterways, and in flood channels [14,20,57].
It does not thrive where there are extended periods of low temperatures
or drought. Perennial ryegrass will do well in areas that are too wet
for other grasses, and short periods of flooding will not severely
reduce good stands [14,49,57]. Josselyn and others [63] listed
perennial ryegrass as a facultative wetland species (it occurs at 34 to
66 percent frequency on wetland sites in California).

Elevation occurrence data from selected western states are as follows
[9]:

feet meters

Utah 3,100-5,100 945-1,555
Colorado 5,000-6,500 1,524-1,981
Wyoming 3,500-6,200 1,067-1,890
Montana 3,200-7,200 975-2,195

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

More info for the term: shrub

FRES10 White - red - jack pine
FRES11 Spruce - fir
FRES12 Longleaf - slash pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory
FRES16 Oak - gum - cypress
FRES17 Elm - ash - cottonwood
FRES18 Maple - beech - birch
FRES19 Aspen - birch
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES22 Western white pine
FRES23 Fir - spruce
FRES24 Hemlock - Sitka spruce
FRES25 Larch
FRES26 Lodgepole pine
FRES27 Redwood
FRES28 Western hardwoods
FRES34 Chaparral - mountain shrub
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES39 Prairie
FRES41 Wet grasslands

More info for the term: high-severity fire

Fire top-kills perennial ryegrass; high-severity fire can kill the
rhizomes [20,21].

Perennial ryegrass is a palatable and nutritious forage for all classes
of livestock and most wild ruminants [14,54]. In a study to determine
the practicality of using Douglas-fir (Pseudotsuga menziesii)
plantations for sheep range, domestic sheep grazed perennial ryegrass
in proportion to its availability [32].

More info for the term: graminoid

Graminoid

More info for the terms: competition, cover, natural, seed, shrub, shrubs, succession, tiller

Perennial ryegrass was probably the first grass to be cultivated as a
pasture grass in Europe. Records of its use in Europe date to 1681.
Thomas Jefferson reported perennial ryegrass as a good producer in
Virginia as early as 1782 [14,16]. Annual productivity averaged 2.5
kg/sq m, aboveground dry weight [33].

Perennial ryegrass is widely planted for range, pasture, hay and turf.
It is one of the more closely studied pasture grasses. There have been
numerous studies on management, nutritive value, and genetics. Many
cultivars are available, conferring various characteristics of pest
and/or disease resistance and particular growth properties [14].

Reaction to grazing: Perennial ryegrass is slower to establish than
common ryegrass, but fully developed stands are equal to common ryegrass
in production and are more persistent [20]. Establishment is, however,
sufficiently rapid to allow grazing at heavy stocking levels as soon as
2 months after seeding [49]. Perennial ryegrass is well suited for use
with subterranean clover (Trifolium subterraneum) for sheep pasture
grazing in late winter and early spring where soil moisture is adequate
for growth [26]. Such pastures can produce up to 4,465 pounds per acre
(5,000 kg/ha) of forage if properly fertilized and maintained [44]. A
study was conducted in Oregon to determine the practicality of a
rotational short-duration grazing system to maximize pasture growth
during the winter or allow rationing of forage produced during the
previous fall. There was little or no forage accumulation in January
and February. The highest cover for perennial ryegrass (measured in
May) occurred on study plots grazed in April (rather than earlier in the
year) [26].

Perennial ryegrass has a higher percentage of standing crop dry weight
with low levels of nitrogen fertilization than with high or no added
nitrogen. Production is best when clipped every 3 weeks (as opposed to
unclipped, or clipped at 1 or 6 week intervals) [37]. Perennial
ryegrass is considered better for pasture than for hay in Alberta [49].

Tiller number decreases immediately after grazing, then increases so
that by May (after grazing in April or earlier) plants have 1.5 to 3
times as many tillers as ungrazed controls [26]. In a growth chamber
study, the initial reaction of perennial ryegrass to clipping was an
immediate regrowth of the damaged leaves, rather than tiller production
[18,37].

Range management practices are generally based on how they affect
carbohydrate reserves of grasses. For perennial ryegrass, the peak
carbohydrate reserves occur just after flowering in late spring and
early summer [55]. Maximum levels of carbohydrate reserves do not have
to be maintained for proper management, rather, the reserves must not
fall below a critical level [60]. The critical level differs with
species and cultivars and is probably affected by fertility and season
[58]. In growth chambers, perennial ryegrass was unable to use
carbohydrate reserves when the reserves fell below 6 percent of dry
weight. At 6 percent, reserves were inadequate for support of the
existing tiller population and some tillers died [60].

Areas of use: In Utah, perennial ryegrass is used in irrigated
pastures, or for dryland use where there is at least 18 inches (460 mm)
annual precipitation and the winters are mild [25].

Competition: Where it is planted with long-lived grass and legumes,
perennial ryegrass should not make up more than 25 percent of the
mixture so that sufficient numbers of the longer lived species can
establish. If it is seeded too heavily in mixtures, it may retard the
growth of the other species [20,42].

Although perennial ryegrass is usually associated with fertile soils,
under low levels of nitrogen it will outyield sheep fescue (Festuca
ovina) and mat nardusgrass (Nardus stricta), which are grasses of
infertile pastures [6]. The highest levels of production are on soils
of medium to high fertility [57].

The practice of seeding grasses on sites managed for conifer
regeneration may result in a decrease in the competitive success of the
conifer seedlings. In a study on Douglas-fir regeneration, Newton and
Cole [43] found that there were proportional decreases in both root and
shoot growth, regardless of competitor type. The survival of ponderosa
pine (Pinus ponderosa) seedlings was reduced where they were planted in
grass mixtures that included perennial ryegrass [5].

The ability of perennial ryegrass to effectively suppress woody species
may be an advantage where grasslands are desired management goals. At
moderate to high densities, perennial ryegrass reduced the dry weight
gain of sugarberry (Celtis laevigata) by up to 84 percent. It is likely
that perennial ryegrass could help inhibit growth of sugarberry on
grasslands undergoing secondary succession [53].

In a study of the effects of perennial grasses on annual weeds,
perennial ryegrass was least able to suppress annual weeds. It is
likely, therefore, that perennial ryegrass may not be the best choice
for rehabilitation of degraded pasture and range that is subject to
invasion by weedy annuals [5].

The use of introduced species for soil stabilization and rangeland
conversion is becoming more questionable because the effect of such
species on the community structure of native plants is still poorly
understood. Management considerations must take into account both the
benefits of erosion control, shrub control and the reduction of shrub
competition with conifers, and the negative aspects of competition for
space and soil moisture with native herbs and shrubs [19]. Perennial
ryegrass has negative effects on natural regeneration of chaparral
because it readily outcompetes native herbs, resulting in a reduction of
wildflowers. In most cases, natural regeneration after fire may be
sufficient without artificial seedings, and has the added benefit of
costing nothing [29].

Perennial ryegrass was well established in all plots 3 years after the
plots were sprayed with various treatment of silvex, picloram and 2,4-D.
The herbicides in the study gave effective 2-year control of woody
plants [44].

Perennial ryegrass does best in fall seedings where winter months are
mild, but seeding too late in the fall will increase winter-kill to
unacceptable levels. Some cultivars have more rapid establishment than
others [14].

Seeding rates for perennial ryegrass are as follows [14,54]:

In mixtures:
5-10 pounds per acre (5.5-11 kg/ha)
4.5-5.4 pounds per acre (5-6 kg/ha) with legume
8 -10 pounds per acre (9-11 kg/ha) with cereal
29 pounds per acre (33 kg/ha) for erosion control
219-348 pounds per acre (245-39 kg/ha) for lawns

In pure stands:
14-25 pounds per acre (16-28 kg/ha)

Perennial ryegrass yields from pure stands grown in western Washington
average from 4.02 to 4.96 tons per acre (9.01-11.12 t/ha) [45].

Diseases and Pests: Crown rust (Puccinia coronata) may severely reduce
forage value in wet areas. Other fungal infections include brown rust
(Puccinia dispersa), and red thread (Corticum fuciforme). Occasional
attacks by Helminthosporum species also occur. Ergot (Claviceps
purpurea) and blind-seed disease (Phialea temulenta) reduce seed yield
and quality [14]. Leaf blotch (Helminthosporium spiciferum), ergot and
blind seed disease can be substantially controlled by burning perennial
ryegrass fields in the spring [21].

The crude protein content of perennial ryegrass increases with soil
nitrogen fertility. Some average values for selected characteristics
are as follows [55]:

crude protein (%) in vitro digestibility (%)
vegetative growth 10.7-18.7 * 88-87
early bloom 10.1-16.9 80-81
heading 13.2 82
mature 9.1 71

* higher values are for higher rates of nitrogen fertilizer

The National Academy of Sciences [41] reported various nutritional
values for perennial ryegrass; typical values for protein content in hay
are as follows:

digestible protein (% of dry weight)

cattle 5.3
domestic goats 5.6
domestic sheep 4.9
horses 5.7
rabbits 6.1

AL AK AZ AR CA CO CT DE GA HI
ID IL IN IA KS KY LA ME MD MA
MI MN MS MO MT NE NV NH NJ NM
NY NC ND OH OK OR PA RI SC SD
TN TX UT VT VA WA WV WI WY AB
BC MB NB NF NS ON PE PQ SK

More info for the terms: cover, prescribed fire

Perennial ryegrass is a popular turf grass, especially in the south
where it remains green all winter [14]. Perennial ryegrass can be used
as a winter cover or forage crop in warmer climates [14,54,57]. It is
used in mixtures with red clover (Trifolium pratense) in rotation with
strawberries (Fragaria x annassa), nursery stock, or vegetables.
Perennial ryegrass is usually allowed to grow for 3 years, providing
soil improvement and sanitation (in addition to silage and hay crops),
then is plowed under as green manure [20].

Perennial ryegrass is used for brushland conversion to range. Chamise
(Adenostoma fasciculatum) brushlands in California are cleared by
disking or burning, and then reseeded. Perennial ryegrass is
recommended (as part of a mixture of species) on better sites above
2,000 feet (610 m) elevation and receiving 28 inches (711 mm) or more of
annual precipitation [4]. Love and Jones [34] recommended it for
coastal areas and at mid- to low elevations (up to 3,000 feet [914 m]).
Hardinggrass (Phalaris tuberosa), tall fescue (Festuca arundinacea) and
legumes are recommended in mixtures with perennial ryegrass for
brushland conversion in certain areas (detailed in [4,42]). Deer use
increases on sites undergoing this type of treatment. In general,
seeding after prescribed fire in brushlands increases the amount and
quality of forage available to big game and livestock [42].

Perennial ryegrass is palatable to livestock and big game species.
Older plants can become tough and unpalatable, especially during hot dry
weather [57].

Palatability ratings from selected western states are as follows [9]:

Wyoming Montana North Dakota

cattle fair fair fair
domestic sheep good fair fair
horses fair fair fair

More info on this topic.

More info for the term: selection

Perennial ryegrass begins growth early in spring. Peak biomass occurs
during cool moist conditions in spring and again in autumn [18].
Flowering occurs from April or May to August, depending on environmental
conditions [14,46]. Seeds are released in late spring and summer and
germination takes place from August to September or as soon as moisture
conditions allow [18,50].

Anthesis dates from selected western states are as follows [9]:

Colorado June-August
Wyoming June-July
Montana May-July
North Dakota June-July

In the southern states, perennial ryegrass will remain green through the
winter [14,20]. In a study of climatic variation in the rate of leaf
expansion, Cooper [8] concludes that Mediterranean populations can
expand in leaf area more rapidly in winter than continental populations.
Maritime populations of perennial ryegrass are intermediate. The
differences appear to be dependent on temperature, perhaps due to past
climatic selection. Populations in Mediterranean climates are adapted
to mild, moist winters and can grow year-round, but populations in
continental climates are winter dormant.

The peak stem carbohydrate reserve levels occur in early summer, just
after flowering begins, dropping off through summer to a low in October.
This is in contrast to many other grasses that have two peaks of
carbohydrate reserves, one in early spring which is depleted by
flowering, then replenished by late summer. Apparently, perennial
ryegrass is more efficient at maintaining carbohydrate reserves through
the flowering period [55].

More info for the term: seed

Fire stimulates the production of reproductive tillers in perennial
ryegrass [14]. When field burning was initiated on seed fields in
Oregon, seed yields tripled [21].

More info for the terms: graminoid, ground residual colonizer, secondary colonizer

Tussock graminoid
Ground residual colonizer (on-site, initial community)
Secondary colonizer - off-site seed

More info for the terms: seed, stratification

Perennial ryegrass is considered self-incompatible [14]. The seeds are
relatively large (0.00027 ounce [7.5 mg]), with no innate dormancy.
There are 247,000 to 330,000 seeds per pound [7,34]. The seeds tolerate
a wide range of diurnal temperature fluctuation, and germinate in either
light or darkness [18]. Casterline Seeds [7] recommended stratification
at 47 degrees Fahrenheit (8 deg C) for 5 days before planting. This is
not consistent with most authors, who do not recognize a need for
stratification. Perennial ryegrass seeds will germinate as soon as
moisture conditions permit, regardless of cold treatment [18,50].
Seedbanks of perennial ryegrass are limited and transient; even where
perennial ryegrass is a major component of pastures in the Netherlands,
it ranks seventh among grasses in numbers of viable seeds and does not
accumulate reserves of seeds [18,52]. Schafer and Chilcote [62]
determined that the largest decrease in buried seed is due to
germination.

This type of transient seedbanking is related to exploitation of
grasslands that are subject to seasonally predictable drought damage,
such as those of mediterranean climates. The lack of a persistent
seedbank explains the tendency of perennial ryegrass to be replaced by
native grasses with persistent seedbanks, especially in the more
northerly latitudes [50].

Along roadsides and in disturbed habitats in the United Kingdom,
perennial ryegrass will reproduce well from seed. In neighboring lawns
or pastures it may be entirely dependent on vegetative reproduction
(probably because the flowering stems are removed before seed production
can occur) [18]. The success of self-seeding for stand maintenance in
the United States would appear to depend on the ability of seedlings to
establish well before frost. Established plants are fairly winter
hardy, but since they are short-lived, recruitment from seed would be
important for stand persistence [18,49,57].

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands

More info on this topic.

More info for the term: seed

Perennial ryegrass is an good competitor and outcompetes other grasses
both above and below the ground [10]. Colonization of disturbed areas
and adjacent areas can take place by seed dispersal [50]. Perennial
ryegrass is probably not shade tolerant; photosynthetic capacity of leaf
bases decreases when they are shaded [64]

More info for the term: natural

The scientific name for perennial ryegrass is Lolium perenne L.
Perennial ryegrass belongs to the family Poaceae, tribe Triticeae
(Hordeae) [16]. It is closely related to the genus Festuca; numerous
natural hybrids between ryegrasses and European species of Festuca have
been reported [16]. Natural hybrids have resulted in great variation in
the characteristics of ryegrass species.

Some authors recognize the following varieties or subspecies [13,23,24]:

Lolium perenne subsp. perenne
Lolium perenne var. cristatum Pers.

Some authors distinguish annual ryegrass (L. p. ssp. multiflorum (Lam.)
Husnot.) and perennial ryegrass (L. p. ssp. perenne) as separate species
due to distinct structural characteristics, even though annual ryegrass
was derived artificially from perennial ryegrass and they readily
hybridize [14,16].

Common ryegrass (Lolium spp.) is a commercial mixture of ryegrass
species which is mostly annual ryegrass but usually contains a
substantial percentage of perennial ryegrass and annual-perennial
hybrids [49,57].

More info for the terms: cover, forb, forbs, seed, wildfire

Perennial ryegrass grows rapidly and is easily established; it is often
used for stabilization of soils [19,20]. Perennial ryegrass is often
seeded in mixtures with slower growing, longer lived species to provide
a quick cover [54]. It is hydroseeded on badly eroded mine spoils in
Virginia and Tennesee as part of a seed mixture containing annual and
perennial grasses, legumes, and native forbs [38]. Streambank
stabilization projects in Utah utilized a grass and forb seed mixture
that included perennial ryegrass [56].

Perennial ryegrass was successfully seeded with orchardgrass (Dactylis
glomerata), white clover (Trifolium repens), annual ryegrass and vetch
(Vicia sativa) for soil stabilization and forage production on severely
burned riparian areas in southwestern Oregon [19]. Fire often alters
the ability of soils to take up water. In a study on soil wettability
after wildfire in lodgepole pine (Pinus contorta) stands in Oregon,
perennial ryegrass was seeded with tall fescue, white clover, lodgepole
pine and ponderosa pine (Pinus ponderosa). Use of a wetting agent had
no apparent effect on plant growth, so it is probably not necessary for
successful reseeding after fire [11]. A mixture of grasses and legumes,
including perennial ryegrass, was planted on an area burned by wildfire
in north-central Washington [22]. In Arizona, seedings that included
perennial ryegrass had low initial cover values immediately following a
wildfire. By the seventh or eighth year, cover values had increased to
nearly 3 times the values on unburned control plots, after which there
was a slight drop in cover values [35].

Perennials, Terrestrial, not aquatic, Rhizomes present, Stolons or runners present, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blade auriculate, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence simple spikes, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 3-7 florets, Spikelets with 8-40 florets, Spikelets solitary at rachis nodes, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets closel y appressed or embedded in concave portions of axis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 1 clearly present, the other greatly reduced or absent, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes 3 nerved, Glumes 4-7 nerved, Glumes 8-15 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma 5-7 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea keels winged, scabrous, or ciliate, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Lolium perenne, common name perennial ryegrass, English ryegrass, winter ryegrass, or ray grass, is a grass from the family Poaceae. It is native to Europe, Asia and northern Africa, but is widely cultivated and naturalised around the world.

Lolium perenne, showing ligule and ribbed leaf