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

 Native Plant Database

Tridens flavus

Purpletop tridens, Redtop tridens, Tall redtop tridens, Purpletop, Redtop, Tall redtop

Poaceae (Grass Family)

Tridens flavus (Purpletop tridens)
Smith, R.W.
Tall redtop or Purple-top is a 2 1/2-7 ft. tall perennial grass with drooping branches bearing widely spaced reddish-purple spikelets. In mass, this species puts a purple top on old fields and open woods. The plant becomes brown in fall.

Image Gallery:

7 photo(s) available

Plant Characteristics

Duration: Perennial
Habit: Grass/Grass-like
Root Type: Fibrous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Shape: Linear
Leaf Venation: Parallel
Inflorescence: Panicle
Fruit Type: Caryopsis
Leaf: Green
Size Class: 3-6 ft.

Bloom Information

Bloom Color: Purple
Bloom Time: Aug , Sep , Oct , Nov


USA: AL , AR , CT , DE , FL , GA , IL , IN , IA , KS , KY , LA , MD , MA , MI , MN , MS , MO , NE , NH , NJ , NM , NY , NC , OH , OK , PA , RI , SC , TN , TX , VT , VA , WV , WI , DC
Native Distribution: S. NH to IL & NE, s. to Mex.
Native Habitat: Roadsides, Open woodlands

Growing Conditions

Water Use: Low
Light Requirement: Part Shade
Soil Moisture: Dry
CaCO3 Tolerance: Low
Soil Description: Dry soils. Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay
Conditions Comments: During early growth it is readily consumed by livestock.


Use Ornamental: Attractive
Use Wildlife: Graze, Nesting material.
Attracts: Butterflies
Larval Host: Cross-line skipper, Broad-winged skipper, Little Glassywing skipper, Large Wood Nymph.

Butterflies and Moths of North America (BAMONA)

Tridens flavus is a larval host and/or nectar source for:
Common Wood Nymph
(Cercyonis pegala)

Larval Host
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Crossline Skipper
(Polites origenes)

Larval Host
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Little Glassywing
(Pompeius verna)

Larval Host
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Broad-winged Skipper
(Poanes viator)

Larval Host
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Last Update: 2015-04-16