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Wildlife, Animals, and Plants
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BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pleuraphis jamesii | Galleta
Galleta is a native, warm season, rhizomatous perennial [39,43,47,92] tolerant of arid,
desiccating environments [17,79,92,94]. Culms have solid internodes [39] with pilose nodes [43] and commonly attain heights between 3 to 24 inches (8-61 cm) [50,94]. Leaves are firm, generally recurved when dry, 0.04 to 0.012 inches (1-3 mm) wide and 0.04 to 6.3 inches (1-16 cm) long [92]. Inflorescence is an erect spike, usually less than 3.5 inches (9 cm) [94], generally 1.2 to 2.8 inches (3-7 cm) long [47].
Although rhizomatous, galleta grows in bunches. Under favorable conditions bunches merge forming a sod [94]. Rhizomes occur 1 to 2 inches
(2.5-5.1 cm) below the soil surface [52] and constitute the majority of underground biomass. The tough, woody, scaly
rhizome may reach 5 to 6 feet (1.52-1.83 m) in length [44]. According to Hassell and Oaks [45], galleta may persist for at least 5 to 7 years.
Roots are commonly found within the upper soil profile, with few roots extending further than 18 inches (50 cm) below the soil surface [94].
Hemicryptophyte
Galleta reproduces through seed and development of adventitious buds on rhizomes. Since galleta is not a prolific seed producer [94], populations are maintained through production of rhizomes [52].
Seed: Soil moisture directly affects the flowering cycle of galleta [26],
with relatively abundant soil moisture providing the cue for initiation of the reproductive phase. Seedstalks emerge under favorable moisture and will not occur during years of below normal precipitation [8,52]. Galleta may produce seed several times within a growing season depending upon frequency and amount of summer precipitation [26].
Seed viability and germination are generally poor [54]. However, seedlings have the potential to arise under dry conditions. Knipe [64] found galleta seeds to germinate at
moisture tensions of 16 atmospheres (101.3 kP). Cress [18] found 10-day old seedlings to have good survival at soil moisture levels down to 2.9% (-3000
kP) under greenhouse conditions.
Vegetative: Vegetative production is closely tied to moisture availability. A
description is found under SEASONAL DEVELOPMENT
Galleta prefers arid and slightly mesic habitats, with competitive abilities
decreasing as moisture
availability increases. Galleta will inhabit areas receiving the majority of annual
precipitation either in summer, or winter and fall [94]. Galleta is adapted to alkaline soils,
both saline and fresh [54] and will grow in fine to coarse textured [54,94] sandy, loam, and clay soils [2].
Platou and others [73] observed edaphic factors associated with galleta within the Great Basin.
Galleta prefers neutral to moderately alkaline soils of relatively low water-holding capacity, with a coarse loamy texture. Soil surface horizons possess a low percent clay, high bulk density and high percentage of rock fragments. Galleta was almost exclusive to soils of moderate temperature (8-15 degrees C)
and relatively mesic moisture regimes (light summer precipitation). Cook and others [17] observed galleta in
the Great Basin on well-drained, gravelly slopes adjacent
to salt deserts. Galleta is a prominent
understory species of pinyon-juniper woodlands experiencing cool, dry winters,
on soils derived from Kaibab limestone, tertiary sands and gravel basalt [45,82].
Regional: In California, galleta occurs on dry, sandy to rocky slopes, and flats within scrub and woodland areas [47]. Dry, sandy plateaus are preferred sites in Arizona. In Utah, dry flats and foothills are preferred [92]. Galleta also thrives on well-drained, sandy soils, and fractured rockland sites of the Colorado plateau region [90]. Preferred sites in Texas are dry rocky ledges, rolling slopes, and valley flats [40].
West and others [94] provide a comprehensive overview of topography and soils where galleta occurs.
Galleta is commonly found between 3,500 and 7,500 feet (1,067-2,286 m) [46].
Elevational ranges by state are listed below:
| AZ |
4,500 to 7,000 feet (1,372-2,134 m) [50] |
| CA |
3,281 to 8,202 feet (1,000-2,500 m) [47] |
| NM |
3,500 to 7,500 feet (1,067-2,286 m) [37] |
According to Hassell and Oaks [45], Galleta may persist
for at least 5 to 7 years, usually lasting 10 to 20 years after disturbance. For
information on its recovery rate after fire, see PLANT RESPONSE TO FIRE.
Phenological records for galleta are extremely variable due to close ties with
seasonal moisture availability [94].
Seedling emergence: Emergence is directly associated with late spring to early
summer moisture
availability, with greatest seedling emergence occurring during wetter years.
In the Great Basin, Humphrey and Schupp [49] found annual seedling emergence of galleta to
begin and end later than the majority of perennial associates. Galleta was found to emerge from June to
July; all other associated species showed February to June emergence
intervals.
Root growth is important during early developmental stages within arid environments.
West and others [94] observed seedlings to achieve up to 9.72 inches (24.7 cm) of root penetration at 6 weeks growth.
Vegetative growth: Moisture availability is the underlying cue for vegetative growth,
with growth patterns corresponding to periods of available moisture [52,94]. A common growing season is May to September. Several periods of dormancy may occur during the growing season when moisture is lacking. In the Utah desert experimental range, galleta was observed to go through 4 growth-dormancy cycles in a single year [39].
Phenological observations of galleta in galleta-shadscale and galleta-sagebrush communities of New Mexico found annual growth beginning late March to early April [26].
Related categories for
SPECIES: Pleuraphis jamesii
| Galleta
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