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Helictotrichon sempervirens - blue avena

Scientific Family
Poaceae
Other common names
blue oatgrass
Plant type
Grasses
Riparian
No

Grass Description

Origin
Introduced
Season
Warm

Frequently grown as an ornamental species. Performs best in soils with good drainage and may rot in heavy soils, especially if over irrigated. The blue color seems best in dryer soils when plant is in full sun or bright shade.

Plant Community
Disturbed Areas
Low elevation
0
High elevation
9000

General Description

Grows 2 to 3 feet tall and wide in clumps of silver-blue blades. Plants cultivated as ornamentals.

Bunchgrass, 2 to 3 feet tall; ligule up to 1/16 inch long, truncate and hairy; sheath nearly open to the base; blades rolled, veins ribbed; basal blades deciduous when dead; seedheads branching 3 to 8 inches long; most branches have 3 to 10 spikelets.

Grass type
Perennial bunchgrass
Rhizomes
No
Stolons
No
Clump Diameter 2 ft or more
Yes
Bushy - highly branched
No
Height with Seedheads
24 inches or more
Seedhead Structure
Branched - open and spreading
Seedhead droops
No
First bloom month
June
Last bloom month
August

Flower Characteristics

Flowers per Spikelet
Multi-flowered
Spikelets One-Sided
Yes
Awns
Less than 1/4 inch
Three Awns
No
Awns bent
No
Flower and Seedhead Notes

Seedhead branches ascend, branches have 3 to 10 spikelets; spikelets with 3 to 5 florets, lower florets awned; glumes subequal to unequal. One-sided seed heads in June begin white then turn golden.

Vegetative Characteristics

Blade is hairy
No
Blade margins white
No
Blade cross-section
Convolute - rolled up longitudinally

Blades up to 2 feet long, 1/8 inch wide, usually rolled, rough to the touch, basal blades deciduous when dead.

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

Not available.