''Hilaria rigida'' (formerly ''

Pleuraphis ''Hilaria'' is a genus of North American plants in the grass family. Members of the genus are commonly known as curly mesquite. They are found in the Southwestern United States, Mexico, and Guatemala. The generic name honors French naturalist Au ...

rigida''Mojave Desert Wildflowers, Pam MacKay, 2nd. Ed 2013, p. 314) is a species of clumping perennial grass that is widespread in California deserts.''Hilaria rigida'', CalFlora Database
CalFlora Database: ''Hilaria rigida'' (big galleta)
/ref> It is commonly known as big galleta.Jepson Desert Manual, Hickman, Ornduff, Constance, 2002, p. 592–593''Mojave Desert Wildflowers'', Pam MacKay, 2nd. Ed 2013, p. 285''Introduction to California Desert Wildflowers'', Philip A. Munz, revised 2004, p. 70''Plants of the East Mojave'', Adrienne Knute, revised ed. 2002, p. 55 It is a monocot in the '' Hilaria'' genus of the grass family (

Poaceae 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 an ...

). It can be recognized after seed dispersal by the wiry, wavy inflorescence stalks ( flexuose) that continue to stick out of the clump of leaf blades. The stems are unusual among grasses in that they are solid, even between the nodes, whereas most grasses have hollow stems. The clumps help stabilize sand

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

s. According to botanist

Philip A. Munz Philip Alexander Munz (1892–1974) was an American botanist, plant taxonomist and educator who worked at the Rancho Santa Ana Botanic Garden and was a professor of botany at Pomona College, serving as dean there for three years. In 1935 Munz publ ...

, "it is said to be one of the most valuable forage grasses of the desert". Clumps can live more than 100 years.

Habitat, range, and distribution

Big galleta is found in sand dunes, bajadas,

scrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, Herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally or ...

s, woodlands, and

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

s. It prefers dry, open, sandy to rocky slopes and flats. It occurs on all soil types, but has poor growth in clay soils. It is tolerant of arid environments such as

floors, and it is the dominant grass in some desert scrub regions.US Forest Service Fire Ecology
/ref> It is found on plains, in sand dunes, and on rocky hillsides. It grows from sea level to about . In the Mojave Desert, it grows up to . It is common in creosote bush scrub,

joshua tree woodland Joshua () or Yehoshua ( ''Yəhōšuaʿ'', Tiberian: ''Yŏhōšuaʿ,'' lit. 'Yahweh is salvation') ''Yēšūaʿ''; syr, ܝܫܘܥ ܒܪ ܢܘܢ ''Yəšūʿ bar Nōn''; el, Ἰησοῦς, ar , يُوشَعُ ٱبْنُ نُونٍ '' Yūšaʿ ...

, and blackbrush scrub plant communities, and areas with sandy soils, such as the Kelso sand dunes. In the eastern Mojave Desert, it is more common than its relative, galleta grass (''

Pleuraphis jamesii ''Hilaria jamesii'' (formerly ''Pleuraphis jamesii'') is a species of grass known by the common name James' galleta. Range and habitat It is native to the southwestern United States, where it is widespread in scrub, woodland, grassland, and pl ...

''). It is a common native to the Mojave Desert and Sonoran Desert to Sonora, Mexico. It can be found in California, Arizona into northern Mexico, Colorado, Utah, less commonly, but also in other parts of Mexico and rarely in sand dunes in Utah's Washington and Kane Counties.

Description

Growth pattern

''Hilaria rigida'' is a long-lived, shrubby or bushy, clumping perennial grass producing coarse, erect stems reaching in maximum height. It spreads from hard, woody

rhizome 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 hori ...

s to form grayish, hairy, open, erect hummocks and clumps. The clumps can live to more than 100 years old. Its primary means of reproduction is by

rhizomes 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 hori ...

, possibly also by tillering. It has a bush-like appearance because it is highly branched at the base.Big Galleta, Range of Plants of Utah, Utah State University
/ref> Clumping results from spread by tillers or short

. Clumps of leaves are wide. Seeds fall when mature, but their stalks persist, sticking out from the clumps like zigzagging wires, by which the plant can be identified at a distance. It is drought tolerant and very fast growing after rains. It typically undergoes two major growth periods, one after winter rains, the other after summer monsoons. It is reported to be more effective than many other desert plants at extracting water from the soil during dry periods.

Roots, stems, and leaves

Roots are shallow and radiate outward from the base of the plant. Fuzzy to wooly stems are stiff, heavy, and coarse, from long. The stems are unusual among grasses in that they are solid, even between the nodes, whereas most grasses have hollow stems. They can be either erect or lying on the ground ( decumbent). Stems have nodes that are lined with long, sometimes curly hairs. Leaf blades are coarse and firm, fairly wide, and almost straight, from grayish to blue-green, sometimes with light wooly fuzz, and have curly hairs and edges that are rolled upward. They are from long. Leaves are attached either to the base of the plant or along the upright stems that bear the heads of seeds.

Inflorescence and fruit

The inflorescence is a series of hairy or brush-like rectangular spikelets, occur in clusters of three, between . The grass produces relatively few viable seeds and spreads mostly by its tillers and sometimes via

s. The inflorescence stalk persists after the seeds drop, sticking out of the clump of leaf blades like stiff, wavy wires. It blooms between December and January according to some sources, from May to June in the Mojave Desert according to others, and from February through June in the Mohave Desert according to others. The variation may result from a paucity of information on

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

characteristics (as of 2014). Seedlings rarely become established. The head of seeds is a spike of seeds with much chaff. Spikes are long.

Ecology

The hummocky, clumpy form of the grass helps it stabilize loose and blowing sand when it grows in desert

habitat. It acts as a

nurse plant Ecological facilitation or probiosis describes species interactions that benefit at least one of the participants and cause harm to neither.Stachowicz, J. J. 2001. Mutualism, facilitation, and the structure of ecological communities. BioScience 51 ...

to seedlings of other species, such as cholla and barrel cactus, in turn receiving protection from herbivory by growing next to the spiny plants. It is not palatable to elk and waterfowl. Associated plant species include '' Larrea tridentata'' (creosote bush), '' Ambrosia dumosa'' (white bursage), '' Coleogyne ramosissima'' (blackbrush), '' Yucca brevifolia'' (joshua trees), '' Yucca'' species, ''

Krameria erecta ''Krameria erecta'' is a species of rhatany known by several common names, including Pima rhatany, purple heather, and littleleaf rhatany. It is native to the southwestern United States and northern Mexico, where it grows in dry areas such as de ...

'' (range ratany), '' Krascheninnikovia'' (winterfat), '' Encelia farinosa'' (brittle bush), '' Ephedra'' species, '' Lycium andersonii'' (wolfberry), and '' Sphaeralcea'' (globemallow).

Uses

Big galleta is heavily grazed and is valuable as a fair to good forage crop for sheep and cattle. Botanist

commented that "it is said to be one of the most valuable forage grasses of the desert". It resprouts after grazing followed by rains, and coarseness and clumping help protect it from trampling. It is used for erosion control and in revegetation efforts.

References

External links

CalFlora Database: ''Hilaria rigida'' (big galleta)Jepson eFlora–TJM2 — ''Hilaria rigida''Grass Manual Treatment for 'Hilaria rigida''USDA Plants Profile for ''Pleuraphis rigida'' (big galleta)''Hilaria rigida'' — U.C. Photo gallery
{{Clear Chloridoideae Grasses of Mexico Grasses of the United States Native grasses of California Flora of Arizona Flora of Nevada Flora of New Mexico Flora of Northwestern Mexico Flora of Sonora Flora of Utah Flora of the California desert regions Flora of the Sonoran Deserts Natural history of the California chaparral and woodlands Natural history of the Colorado Desert Natural history of the Mojave Desert Natural history of the Peninsular Ranges Taxa named by George Bentham Flora without expected TNC conservation status