''Hilaria mutica'', synonym ''Pleuraphis mutica'', is a species of
grass
Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...
known by the common name tobosa, or tobosa grass. It is native to Northern
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ke ...
, Oklahoma, and Texas.Uchytil, Ronald. (1988) ''Pleuraphis mutica''. In: Fire Effects Information System, nline U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Retrieved January 15, 2012.
Description
''Hilaria mutica'' is perennial grass that is
rhizomatous
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow ho ...
and forms
sod
Sod, also known as turf, is the upper layer of soil with the grass growing on it that is often harvested into rolls.
In Australian and British English, sod is more commonly known as ''turf'', and the word "sod" is limited mainly to agricult ...
. It usually grows tall, sometimes reaching up to . The stems have decumbent bases and erect tops.
Most of the stiff, hairless leaves are basal. They are up to long. The bases of the stems come from a thick, woody rootstock and a system of roots that penetrates up to deep in the soil.
The
inflorescence
An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...
is a few centimeters long and is white, straw, or purplish. Spikelets are borne in clusters of three. The plant reproduces mainly by spreading by its rhizome, and does not often form viable seeds. The plant is susceptible to ergot.''Hilaria mutica''. Grass Manual Treatment. Retrieved January 15, 2012.
Distribution
''Hilaria mutica'' is one of the most common species on the semidesert
grassland
A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
s in the region. It is a
climax species
Climax species, also called late seral, late-successional, K-selected or equilibrium species, are plant species that can germinate and grow with limited resources; e.g., they need heat exposure or low water availability. They are the species wi ...
on frequently flooded lowlands. It also occurs on upland territory. Habitat types that feature the grass include pinyon-juniper woodland and mesquite, creosote, and grassy shrubsteppe. It does best on land that is flooded for a few days and then dries up. It also grows on drier soils, and it is somewhat
drought
A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...
-tolerant.
It grows on
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
with
honey mesquite
''Prosopis glandulosa'', commonly known as honey mesquite, is a species of small to medium-sized, thorny shrub or tree in the legume family (Fabaceae).
Distribution
The plant is primarily native to the Southwestern United States and Northern M ...
forage
Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used ...
for cattle and horses in the American Southwest. It is productive and palatable until it becomes rough at maturity. It is especially valuable during drought when it persists after other grasses die. It can be cut into
hay
Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticat ...
when still green. In
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
, it yields 1000 pounds per acre, and this can be increased with careful and deliberate management. In areas with adequate precipitation, burning is used to remove litter, which then stimulates the stems to produce more green matter.
The grass can cause ergot poisoning if eaten when infested with the fungus.