• GENERAL BOTANICAL CHARACTERISTICS
• RAUNKIAER LIFE FORM
• REGENERATION PROCESSES
• SITE CHARACTERISTICS
• SUCCESSIONAL STATUS
• SEASONAL DEVELOPMENT

GENERAL BOTANICAL CHARACTERISTICS:

Bush muhly is a drought-resistant, native perennial bunchgrass. Plants reach up to 3 feet (1 m) in height and are often highly branched [22,44,30].

RAUNKIAER LIFE FORM:

Hemicryptophyte

REGENERATION PROCESSES:

Bush muhly regenerates by seed. Bush muhly seeds composed about 33% of the seedbank near Globe, Arizona [34]. Milton and others [31] found that that bush muhly made up the largest portion of construction material in cactus wren nests, and that the nests contained viable seeds. They suggested that the cactus wren is an important diperser of bush muhly seeds, capable of spreading them as far as 213 feet (65 m).

Bush muhly seedlings, shoots, and roots are all adversely affected by a high temperature regime. In a growth chamber study, Sosebee and Herbel [37] obtained an optimum germination rate of 84% under a temperature range of 68 to 95 degrees Fahrenheit (20-35 ^oC) with alternating light and dark periods. Seedling survivorship after 21 days was 94% with maximum soil temperatures of 102 degrees Fahrenheit (39 ^oC) and 5% with a maximum soil temperature of 122 degrees Fahrenheit(53 ^oC)). Ashby and Hellmers [1] concluded that bush muhly germinated best at 86 degrees Fahrenheit (30 ^oC).

SITE CHARACTERISTICS:

Generally, bush muhly grows on low elevation semidesert grassland ranges in good condition, as well as in deserts. It occurs on mostly rocky or sandy sites on lower plains, dry mesas, canyons, foothills, and open hillsides from 760 to 4,300 feet (230-1300 m). In Colorado it ranges up to 6,500 feet (1900 m) [12]. Throughout much of its range bush muhly is often found growing under the protection of shrubs, such as mesquite and creosotebush, more than in open areas [2,6,10,16,22,27,30,32,43].

Growth of bush muhly on various soil textures in Utah is rated as follows [12]:

Gravel        Poor
Sand          Good
Sandy loam    Good
Loam          Good
Clay loam     Good
Clay          Fair
Dense clay    Poor

SUCCESSIONAL STATUS:  

Bush muhly is considered a climax species [16]. Bush muhly was dominant throughout much of the desert grassland of New Mexico, but is now secondary to fluffgrass (Erioneuron pulchellum), burrograss (Aplopappus tenuisectus), and threeawns (Aristida spp.) [43]. Bush muhly originally existed in extensive stands, but now is generally found growing under the protection of shrubs [10,43]. Bush muhly may decrease greatly on heavily grazed rangeland, but may be a substantial component of mesa rangelands in the process of recovery. Bush muhly is shade tolerant, and survives beneath mesquite canopies [20].

SEASONAL DEVELOPMENT:

Bush muhly begins growth from late winter to early spring and flowers from early spring to early summer [22,25,27]. Given sufficient moisture, bush muhly does not back to the root crown in winter, and new growth starts from near the base of the previous year's stems [22,30]. Phenology of bush muhly in the northern Chihuahuan Desert of New Mexico was [25]:

new growth     Feb.-April
flowers           April-May
fruits mature   mid-Sept.

Related categories for SPECIES: Muhlenbergia porteri | Bush Muhly