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

GENERAL BOTANICAL CHARACTERISTICS:

Columbia needlegrass is a native, cool-season, perennial bunchgrass that grows in dense, leafy tufts [48]. It is long-lived and drought tolerant, with a slow to moderate seedling growth rate and medium herbage volume [19]. Culms are erect, 1-3.3 ft (0.3-1 m) tall, and stout. Leaves are narrow and mostly basal. Much of the foliage remains green throughout the growing season [53].

Panicles are 2.8-11.8 in (7-30 cm) long, narrow and dense, borne on short, appressed branches [48]. Spikelets are one-flowered, 0.2-0.3 in (5-7 mm) long; callus is pointed and sharp when mature; awns are 0.7-1.3 in (1.8-3.3 cm) long [48].

Roots are deep and fibrous, frequently extending vertically more than 3 feet (0.9 m) [45,53].

RAUNKIAER LIFE FORM:

Hemicryptophyte

REGENERATION PROCESSES:

Columbia needlegrass reproduces by seed and by tillers [48]. Stubbendieck and others [48] provide the only mention of tillers in the literature. Tisdale and Hironaka [51] state that reproduction is entirely by seed in needlegrasses. Seed is typically produced in abundance and ripens during the late summer and early fall [40,51]. The sharp, pointed callus and awns aid in seed dispersal by ready attachment to coats of animals [51]. Columbia needlegrass may regrow in the fall with adequate moisture [48]. Because of the sharp pointed callus, Columbia needlegrass is avoided from the time of seed maturation until the ripe seed falls to the ground. This morphological adaptation promotes stand replenishment [48].

SITE CHARACTERISTICS:

Columbia needlegrass prefers well-drained, fine-textured soils with clay loam to sandy loam surface texture [19]. It has low fertility requirements and good heat tolerance, does well on shallow soils, is moderately tolerant of salinity, and can form a good ground cover on dry, rocky, infertile sites [19].

Columbia needlegrass grows on a wide variety of middle and upper elevation sites [21]. It occurs in dry plains, meadows and open woods in foothills and mountains [48] from the upper sagebrush zone to subalpine sites [53].

This species typically occurs as scattered individuals in uppermost elevations and moist sites of sagebrush [51] and mountain-brush zones [6], but is prominent in denser stands in the open parkland and drier sites of subalpine zones [55]. It also grows in extensive stands in the central Rockies but more often grows as scattered plants at the northern and southern edges of its range [53].

Columbia needlegrass is important at medium and high altitudes [21] and appears at the following elevations [25,28,40,50,55]:

State	Elevation in feet
AZ	5,000-8,000 (1,640-2,440m)
CA	7,000-10,000 (2,290-3,050m)
CO	7,000-8,030 (2,300-2,450m)
NM	6,200-7,300 (1,890-2,225m)
UT	above 8,000 (2,440m)

SUCCESSIONAL STATUS:

Columbia needlegrass is a climax species in many sagebrush and pinyon-juniper communities [15,26,28,49,50]. It has also been found to be a successional species after fire in higher elevation vegetation zones in New Mexico, and has been observed in recently burned areas [26].

SEASONAL DEVELOPMENT:

Columbia needlegrass begins growth in early spring. In sagebrush communities, seed ripens and disseminates in early and late July, respectively [51]. In the Sierra Nevada of California, seed generally ripens in August and September [40]. Foliage remains green throughout a long growing season and occasionally remains green until snow falls [53].

Related categories for SPECIES: Achnatherum nelsonii | Columbia Needlegrass