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Setaria macrostachya - large-spike bristlegrass

Scientific Family
Poaceae
Synonyms
Chaetochloa gibbosa, C. macrostachya, C.amaeraphis setosa var. macrostachya, Panicum macrostachyum and more, See SEINET.
Plant type
Grasses
Riparian
No

Grass Description

Origin
Native
Season
Cool
Warm

Found on dry flats and in washes, often in partial shade of trees and shrubs.

Plant Community
Interior Chaparral
Montane Conifer Forest
Pinyon Juniper Woodlands
Low elevation
3500
High elevation
7000

General Description

Robust, somewhat erect perennial with leaves 1/2 to 3/4 inch wide, columnar spike-like panicles 4 to 12 inches long; spikelets are very rounded on the back.

Densely tufted, exceeds 2 feet; stems somewhat bent, rough below nodes; dense spikelike seedheads; subspherical spikelets usually subtended by one 3/8 to 3/4 inch bristle, bristles rough to the touch on the upper surface, palea shorter than the lemma.

Grass type
Perennial bunchgrass
Rhizomes
No
Stolons
No
Clump Diameter 2 ft or more
Yes
Bushy - highly branched
No
Height with Seedheads
Greater than 36 inches
Seedhead Structure
Branched - contracted
Seedhead droops
No
First bloom month
May
Last bloom month
October

Flower Characteristics

Flowers per Spikelet
Multi-flowered
Spikelets One-Sided
No
Awns
Absent
Three Awns
No
Awns bent
No
Flower and Seedhead Notes

Seedheads rarely branched distally, rough below the nodes and panicles. Spikelets 1/16 inch, not quite round, 2-flowered, pale green. Lower glumes 1/3 to 1/2 as long as the spikelets, upper glumes about 3/4 as long as the spikelets.

Vegetative Characteristics

Blade is hairy
No
Blade margins white
No
Blade cross-section
Flat

Blades 6 to 8 inches long, 1/4 to 3/4 inch wide, flat, with rough upper surface.

Sheath is hairy
Yes
Tufts of hair top of sheath or collar
No
Ligule
Hairy
Auricles
No

Not available.