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Alligator-weed

Alternanthera philoxeroides

Last reviewed: June 2026

Alligator-weed (Alternanthera philoxeroides)
Photo: National Plant Data Center, Baton Rouge, LA 70874-4490 USA. / Wikimedia Commons (Public domain)

Light

full sun

Water

high

Size

12"–36" H × 24"–120" W

Bloom

Jun, Jul, Aug

Native to

AR

Browse plants for this ecoregion

Edwards PlateauTexas Blackland PrairiesEast Central Texas PlainsWestern Gulf Coastal PlainSouth Central Plains

Alligator-weed is an aggressive aquatic and semi-aquatic vine that spreads rapidly through waterways and wet areas. This invasive species forms dense mats that can quickly overtake native vegetation and is extremely difficult to control once established.

In an HOA neighborhood

Alligator-weed takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.

  • Classified as invasive species
  • Spreads aggressively and uncontrollably
  • May violate local noxious weed ordinances

Wildlife value

While it may provide some habitat for aquatic insects, this invasive plant displaces native species that offer much better wildlife value. Its aggressive nature actually reduces overall biodiversity in affected areas.

Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Does Alligator-weed fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.

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