Lady Bird Johnson Wildflower Center - The University of Texas at Austin information

 Native Plant Database

Aristida purpurea

Purple threeawn, Purple 3-awn, Purple three-awn, Red threeawn

Poaceae (Grass Family)

Aristida purpurea (Purple threeawn)
Hampton, Nan
Often in large bunches, the culms and leaf blades of this grass rise 12-20 in. in height. The seedhead is narrow and nodding with lax, purplish branches. Three long, bristles occur from each flower.

Image Gallery:

13 photo(s) available

Plant Characteristics

Duration: Annual
Habit: Grass/Grass-like
Root Type: Fibrous
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Shape: Linear
Leaf Venation: Parallel
Fruit Type: Caryopsis
Size Notes: Low tufted culms 25-70 cm. tall.
Autumn Foliage: yes
Size Class: 1-3 ft.

Bloom Information

Bloom Color: Purple
Bloom Time: Apr , May , Jun , Jul , Aug , Sep , Oct


USA: AZ , AR , CA , CO , ID , IL , IA , KS , LA , MN , MT , NE , NV , NM , NC , ND , OK , OR , SC , SD , TX , UT , WA , WY
Canada: AB , SK
Native Distribution: Throughout Texas north to Utah, Colorado and Kansas, south to northern Mexico.
Native Habitat: Sun, open ground, well-drained sand, clay, loam, limestone; Overgrazed ranges, disturbed roadsides, abandoned fields.

Growing Conditions

Water Use: Low
Light Requirement: Sun
Soil Moisture: Dry
CaCO3 Tolerance: High
Drought Tolerance: High
Soil Description: Dry, rocky soils.
Conditions Comments: With a gentle breeze passing through purple three-awn inflorescences (grass flowers), a dreamer can imagine that the earth has purple hair. This low-growing prairie grass is good for erosion control on banks and provides a root matrix for many wildflower species. Purple three-awn is an early successional species.


Use Wildlife: Seldom grazed. The seeds are food for some song birds, like the Junco. The plants provide nesting materials or habitat for some fur and game animals.
Conspicuous Flowers: yes
Interesting Foliage: yes
Attracts: Butterflies
Larval Host: Skippers, Satyrs
Deer Resistant: High

Last Update: 2011-01-06