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

GENERAL BOTANICAL CHARACTERISTICS:

Onespike oatgrass is a native, densely tufted perennial bunchgrass [5,17,44]. The centers of the spreading tufts ultimately die out and old sheaths persist at the base of the plants [5]. Culms typically grow 4 to 12 inches (10-30 cm) in height [5,16,26,44]. The inflorescence is a panicle mostly reduced to a single spikelet, but 2 or 3 spikelets may occasionally be present [5,17,18,26]. The root system of onespike oatgrass is shallow and fibrous [20,31,33].

RAUNKIAER LIFE FORM:

Hemicryptophyte

REGENERATION PROCESSES:

Little information on the regenerative processes of onespike oatgrass is available in the literature.

Danthonia species reproduce by seed and tillering from the base [8,15,35,39,41]. Spikelets located in the axils of the lower leaves of onespike oatgrass are self-fertilizing [31,44].

SITE CHARACTERISTICS:

Onespike oatgrass occurs on dry to moist sites from prairies and foothills to open parks and ridges at higher elevations [5,16,18,26,44]. Sites are often rocky with shallow, poorly drained soils [7,14,16,26,33]. Stands of onespike oatgrass are limited to intermediate elevations in the Sierra Nevada and in northeastern California, where they occur in high desert or lava areas [31]. Onespike oatgrass grows at elevations of 2,970 to 10,560 feet (900-3200 m) in California [16], and 7,000 to 10,000 feet (2130-3050 m) in Utah [44].

Onespike oatgrass frequently codominates plant communities with Sandberg bluegrass on bluegrass scablands characterized by thin, rocky soils. These scablands are typically located on intermountain plateaus and ridges derived from Columbia River basaltic flows east of the Cascade Mountains and west of the Rocky Mountains in the Pacific Northwest [32]. Similar scablands are described on central Oregon pumice-derived substrates [32,40].

SUCCESSIONAL STATUS:

Onespike oatgrass is referred to as a climax species on thin soil scablands of the Intermountain Pacific Northwest, where shallow soil depths and bedrock limit the establishment of deeper-rooted plants. In the same region, onespike oatgrass is an invader on deep-soil sites dominated by fescues (Festuca spp.) where moisture retention has been diminished by overgrazing [21]. Onespike oatgrass has also been found on disturbed sites such as trail edges in ponderosa pine forests of eastern Washington and northern Idaho [6].

Johnson and Simon [22] report that onespike oatgrass is a principal indicator species of scabland communities of the Wallowa-Whitman National Forest. It is present in mid- to late-seral stages on moist microsites in bluebunch wheatgrass-Sandberg bluegrass plant associations, as well as early to late seres of stiff sagebrush/Sandberg bluegrass associations. Within this study area, onespike oatgrass often colonizes areas downslope from water sources, where soil moisture is retained for longer periods in the summer. It has been observed to decline with disturbance that increases bare ground. The authors distinguish Sandberg bluegrass-onespike oatgrass plant associations in this region, but are speculative as to whether these sites are climax or a result of severe site degradation of Idaho fescue-prairie junegrass communities.

SEASONAL DEVELOPMENT:

Onespike oatgrass generally flowers from June to August [5,8].

Related categories for SPECIES: Danthonia unispicata | Onespike Oatgrass