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Taxonomy |
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Synonymy:
Oryzopsis hymenoides (Roem. and Schult.) Ricker., Stipa
hymenoides Roemer & J.A. Schultes, Eriocoma cuspidata
Nutt.
Latin name meaning: Oryzopsis is derived from the Greek
word oruzu, rice, and opsis, appearance (22,23)
Family: Poaceae
Common name: Indian ricegrass, sand grass
Similar species: White grained mountain-rice grass (Oryzopsis
asperifolia) and short-awn rice grass (Oryzopsis pungens). |
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Key Identification Characteristics |
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Growth form:
Indian ricegrass is a perennial grass that grows in dense clumps.
Plants eventually become doughnut shaped because the centers
of plant die (16). Plants are 3-7dm tall.
Roots: Roots are fibrous, deep (150 cm)(21) and they may
have a rhizosheath formed by sand grains encasing the roots of
the grass. Rhizosheaths are important because nitrogen fixation
is associated with them, along with water retention and uptake
(2, 26, 28). Root hairs hold sand grains in place, along with
cementing agents secreted by the plant (2). Indian ricegrass
can adjust to shifting sands by elongating basal internodes and
producing adventitious roots at these nodes (20). Leaves:
Leaves are slender (5mm) and nearly as long as the stems; margins
are typically rolled inward
Sheaths: Leaf sheaths are round, split, prominently veined,
usually with a fringe of hairs at throat. The base of leaf sheaths
is often purple.
Ligules: Ligues are membranous, to 8 mm long, pointed,
and conspicuous.
Inflorescence: The inflorescence is a loose panicles,
10-20 cm long, with panicle branches in pairs, spreading and
flexible. Glumes are ovate-long-pointed, thin, papery with 3
or 5 greenish nerves, 6-7 mm long, and hairless to finely hairy.
Lemmas are 3-4 mm long, densely long soft-hairy with white hairs,
turning blackish at maturity. Awns are 4-6 mm long and deciduous. |
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Ecological & Physiological
Relations |
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Life history:
Indian ricegrass is a short-lived perennial; growth usually declines
by the fifth year with a maximum age of 30 years (24)
Native/Introduced: Indian ricegrass is a native grass
to North America
Photosynthetic pathway: C3
Distribution: Indian ricegrass grows from Alberta, Arizona,
British Columbia, California, Colorado, Idaho, Kansas, Manitoba,
Minnesota, Montana, Nebraska, Nevada, New Mexico, North Dakota,
Oklahoma, Oregon, Saskatchewan, South Dakota, Texas, Utah, Washington,
Wyoming and into Mexico(9, 31, 34). Indian ricegrass is one of
the most drought-enduring, native grasses in North America (22).
Indian ricegrass usually grows on well-aerated rocky or sandy
soils such as sand dunes, dry exposed river banks, eroded slopes,
and sandy grasslands (9, 22, 23, 31, 34)
Succession: Indian ricegrass is often associated with
primary succession on disturbed sandy soils (9, 21, 22, 23, 31).
It grows from seeds in caches made by rodents, and is often seeded
by humans to stop wind erosion of sandy soils (7, 9, 10, 11,
19, 31,). It is often the dominant perennial grass on salt desert
ranges of western North America (29).
Canopy/ground cover, LAI, height: Indian ricegrass is
an important native species for revegetation of unstable sandy
dry soil (7, 10, 11, 32), and can reach a height of 7 dm (23)
under good growing conditions.
Competitive ability as seedlings, in mixes, invasive:
Indian ricegrass is well adapted to desert environments, it flowers
prolifically, and sets seed quickly; vernalization is not required
for flowering (20). Germination of seeds is low unless scarified,
aged, or stratified (5, 9, 12, 29, 30, 32). In very sandy and
dry environments Indian ricegrass may be the only plant to emerge
(26). |
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Management Considerations |
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Grazing:
Indian ricegrass is palatable for most grazing animals, and can
sustain relatively high grazing pressure if it is allowed to
produce enough seed for reproduction. Indian ricegrass is a decreaser
under grazing and has disappeared as a prominent species in some
areas because of improper grazing management (23). It is preferred
by livestock and cures well for winter fe (3, 23, 31, 34). Indian
ricegrass decreases under grazing because grazing removes the
seeds, and therefore plants are not replaced. Indian ricegrass
is a short-lived perennial and therefore death is the result
of age, because grazing has no significant effect on its longevity
(1). Long-term, heavy grazing has little effect on root and crown
biomass, and it does not affect the non-structural carbohydrate
reserves, or the seasonal cycle of reserves of this grass (15).
Heavy grazing eliminates or greatly reduces non-resistant genotypes.
Indian ricegrass has a high regrowth capacity rather than defense
mechanisms to overcome intense herbivory (13, 15).
Burning: Because Indian ricegrass establishes from seed,
it will usually re-colonize a burnt area within 2-4 years by
seeds brought in from surrounding un-burnt areas or from seed
buried in the soil (34)
Restoration: Indian ricegrass is adapted for revegetation
on sandy, arid areas in the western U.S. and Canada (5). It is
has been used for re-vegetating coal and oil shale, as well as
uranium mine tailings (26, 32). Germination of this grass is
often low and the seed very expensive. Much research has been
conducted into increasing germination and decreasing seed shattering.
Increasing germination: Under natural conditions rodents collect
bury seeds for winter food; seeds that are not consumed germinate
from these caches (10). Rodents may find the seeds and eat many
of them before they can germinate. The lemma and palea of the
caryopsis limit oxygen transfer to the embryo, along with embryo
dormancy decrease germination (5, 11, 19, 29). Germination of
seeds with the lemma and palea removed is much higher than for
complete seeds (12, 29, 30). Mechanical or acid scarification
can increase germination (5, 12, 17, 19, 29, 30). Scarification
may make the seed more susceptible to diseases (12, 17, 29, 30).
Older seeds with lower vigor may respond negatively to scarification.
Aging seeds and pre-chilling can also increase germination (5,
9, 32).
Seeding: Indian ricegrass seeds can germinate from a depth
of 15 cm, but best emergence occurs when seeds are planted at
a 5 cm depth (31). Greatest germination occurs at low seeding
rate (0.3 kg/ha) perhaps because of decreased intraspecific competition
or because it was harder for predators find seeds. Seeds planted
in fall germinate best probably because of chilling during the
winter and seed aging (9, 31). Commercial varieties available
include Poloma, Nezpar, and Rim Rock. |
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References |
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- Alzerreca-Angelo, H., E.W. Schupp and
S.G. Kitchen. 1998. Sheep grazing and plant cover dynamics of
a shadscale community. J. Range Manage. 51:214-222.
- Bristow, C.E., G.S. Campbell, L.H. Wullstein
and R. Neilson. 1985. Water uptake and storage by rhizosheaths
of Oryzopsis hymenoides: A numerical simulation. Physiol
Plant. 65:228-232.
- Cook, C.W., K. Taylor and L.E. Harris.
1962. The effect of range condition and intensity of grazing
upon daily intake and nutritive value of the diet on desert ranges.
J. Range Manage. 15:1-6.
- Everett, R.L., P.T. Tueller, J.B. Davis
and A.B. Bnmner. 1980. Plant phenology in galleta-shadscale and
galleta-sagebrush associations. J. Range Manage. 33:446-450.
- Griffith, L.W. and D.T. Booth. 1988. Indian
ricegrass seed damage and germination responses to mechanical
treatments. J. Range Manage. 41:335-337.
- Jones, T.A. and D.C. Nielson. 1989. Self-compatibility
in "Paloma" Indian ricegrass. J. Range Manage. 42:187-190.
- Jones, T.A. 1990. A viewpoint on Indian
ricegrass research: its present status and future prospects.J.
Range Manage. 43:416-420.
- Jones, T.A. and D.C. Nielson. 1992. High
seed retention of Indian ricegrass. J. Range Manage. 45:72-74
- Jones, T.A. and D.C. Nielson. 1992. Germination
of prechilled mechanically scarified and unscarified Indian ricegrass
seed. J. Range Manage. 45:175-179
- McAdoo, J.K., C.C. Evans, B.A. Roundy,
J.A. Young and R.A. Evans. 1983.
Influence of heteromyid rodents on Oryzopsis hymenoides
germination Seed collecting and caching activities, on sandy
desert rangelands, Nevada. J. Range Manage. 36:61-64
- McDonald, M.B. Jr. and A.A. Khan. 1977.
Factors determining germination of Indian ricegrass seeds. Agron.
J. 64:558-563.
- McDonald, M.B.,Jr. and A.A. Khan. 1983.
Acid scarification and protein synthesis during seed germination
Oryzopsis hymenoides, gibberellin, abscisic acid. Agron
J. 75:111-114.
- Meijen, E. vander, M. Wijn and HJ. Verkaar.
1988. Defense and regrowth, alternate plant strategies in the
struggle against herbivores. Oikos 51:355-363.
- Orodho, A.B., R.L. Cuany and M.J. Trlica.
1998. Previous grazing or clipping affects seed of Indian ricegrass.
J. Range Manage. 57:37-41.
- Orodho, A.B. and M.J. Trlica. 1990. Clipping
and long-term grazing effects on biomass and carbohydrate reserves
Indian ricegrass. J. Range Manage. 42:53-57.
- Pearson, L.C. 1979. Effects of temperature
and moisture on phenology and productivity of Indian ricegrass.
J. Range Manage. 32: 127-I 34.
- Plummer, A.P. and N.C. Frischknecht. 1952.
Increasing field stands of Indian ricegrass. Agron. J. 44:285-287.
- Reynolds, T.D. and L. Jr. Fralley. 1989.
Root profiles of some native and exotic plant species in southeastern
Idaho. Environ Exp. Bot. 29:241-248.
- Rogler, G.A. 1960. Relation of seed dormancy
of Indian ricegrass [Oryzopsis hymenoides (Roem. &
Schult.) Ricker] to age and treatment. Agron. J. 52:470-473.
- Stoddart, L.A. and J.J. Wilkinson. 1938
Inducing germination in Oryzopsis hymenoides for range
reseeding. J. Amer. Soc. Agron. 30:763-768.
- Tannas, K. 1997. Common plants of the
Western Rangelands. Vol. 1. Curriculum and Instructional Development
Services, Lethbridge Community College. Ronald's Printing, Calgary,
AB.
- United States Department of Agriculture.
reprinted 1988. Range plant handbook. Dover ed. Mineola, N.Y.
- Ward, A.L. 1971. In vitro digestibility
of elk winter forage in southern Wyoming. J. Wildl. Manage. 35:681-688.
- West, N.E. 1979. Survival patterns of
major perennials in salt desert shrub communities of southwestern
Utah. J. Range Manage. 32:442-445.
- Whalley, R.D.B., T.A. Jones, D.C. Nielson
and R.J. Mueller. 1990. Seed abscission and retention in Indian
ricegrass. J. Range Manage. 43:291-294.
- Wullstein, L.H. 1980. Nitrogen fixation
(acetylene reduction) associated with rhizosheaths of Indian
ricegrass (Oryzopsis hymenoides) used in stabilization
of the Slick Rock, Colorado tailings pile. J. Range Manage. 33:204-206.
- Wullstein, L.H. 1991. Variation in N2
fixation (C2H2 reduction) associated with rhizosheaths of Indian
ricegrass (Stipa hymenoides). Amer. Midl. Natur. 126:76-81.
- Wullstein, L.H., M.L. Bruening and W.B.
Bollen. 1979. Nitrogen fixation associated with sand grain root
sheaths (rhizosheaths) with Bacillus polymyxa-like bacteria of
certain xeric grasses Oryzopsis hymenoides, Agropyron dasystachyum,
Aristida purpurea. Physiol. Plant. 46:1-4.
- Young, J.A. and R.A. Evans. 1984. Germination
of seeds of 'Paloma' and 'Nezpar' Indian ricegrass (Oryzopsis
hymenoides). J. Range Manage. 37:19-21.
- Young, J.A., R.A. Evans and D.A. Easi.
1985. Enhancing germination of Indian ricegrass seeds with sulfuric
acid. Agron J. 77:203-206.
- Young, J.A., R.R. Blank, W.S. Longland
and D.E. Palmquist. 1994. Seeding Indian ricegrass in an arid
environment in the Great Basin. J. Range Manage. 47:2-7.
- Zemetra, R.S., C. Havstad and R.L.Cuany.
1983. Reducing seed dormancy in Indian ricegrass (Oryzopsis
hymenoides) revegetation, western United States and Canada,
forage crop. J. Range Manage. 36:239-241.
- http://www.mip.berkeley.edu/query_forms/browse_checklist.html. 2000. A synonymized checklist of the vascular
flora of the United States, Canada and Greenland. Biota of North
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- http://svinet2.fs.fed.us/database/feis/ [1998,March 12]. Fire Effects Information System
[Online] (1996, September). Prescribed Fire and Fire Effects
Research Work Unit, Rocky Mountain Research Station (producer).
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