Threeawns Aristida

Threeawns include keep-away choices: purple threeawn and pineland threeawn have explicit unfavorable fire assessments.

Girona's 2020 fire-prevention gardening guide marks purple threeawn (Aristida purpurea) not recommended. Its assessment concerns garden suitability and combines fire evidence with fuel structure, maintenance and other plant characteristics. It is broader than a measurement of how quickly one sample ignites.

For pineland threeawn (Aristida stricta), North Carolina's 2005 landscaping guide used the extreme-flammability class; its 2025 successor places the species in the high-flammability table. The Forest Service's review explains a physical concern: abundant, fibrous leaves and a high proportion of dead foliage make this species highly flammable. Burning its stands tends to remove the aboveground growth.

That same review describes pineland threeawn as adapted to fire, with growing points protected below the soil surface. Fire adaptation therefore coexists with highly flammable foliage in this grass. Its ability to persist in a fire-shaped ecosystem should not be mistaken for low fuel flammability beside a home.

Rated as a group: threeawn Aristida Awaiting evidence Limited evidence 16 sources rate the genus as a whole. Species evidence never rolls upward into a genus verdict, and genus claims never override a species record. ›

Keep away: 3 species

Awaiting evidence: 8 species

About threeawns

Directory notes

Plant forms recorded in this group: grass, perennial. The records span published USDA zones 7–7. These are record-level fields, not a whole-genus flammability claim.

More about Aristida: Wikipedia — external references; not evidence sources.

Where rated threeawns grow

Tagged as growing in 18 states.

The answer for threeawns is no. Here is what to plant instead.

Alternatives matched by form and place, each carrying its own evidence.

Alternatives to sixweeks threeawn →

See Aristida on Grow → · JSON