Host an Event Volunteer Join Tickets

Support the plant database you love!


Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

Enter a Plant Name:
Or you can choose a plant family:
Thalia geniculata (Bent alligator-flag)
Cressler, Alan

Thalia geniculata

Thalia geniculata L.

Bent Alligator-flag, Arrow Root

Marantaceae (Prayer-Plant Family)

Synonym(s): Thalia trichocalyx

USDA Symbol: THGE2

USDA Native Status: L48 (N), PR (N)

The lance-shaped leaves of Bent Alligator-flag or Arrow Root, with blades 1-2 ft. long and about half as wide, have petioles up to 3 ft. long. The lax, branching inflorescence of blue & purple flowers in open panicles may be 3 ft. tall. The entire plant grows 6-10 ft. in height.

The light green foliage on their stalks gives these conspicuous plants the name “flags.” They are related to the banana and the canna.


From the Image Gallery

2 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Fruit Type: Capsule
Size Notes: Up to about 10 feet tall.

Bloom Information

Bloom Color: Blue , Purple
Bloom Time: May , Jun , Jul , Aug , Sep , Oct , Nov , Dec


Native Distribution: FL to the West Indies
Native Habitat: Stream & pond margins; wet ditches

Growing Conditions

Light Requirement: Part Shade
Aquatic: yes
Soil Description: Shallow water or poorly drained, wet soils.


Commercially Avail: yes

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Thalia geniculata in USDA Plants
FNA: Find Thalia geniculata in the Flora of North America (if available)
Google: Search Google for Thalia geniculata


Record Modified: 2023-02-28
Research By: TWC Staff

Go back