NPSOT Logo
Join / Renew / Gift Donate Shop Member Portal Language
Search

Native Plant Society of Texas

Purpletop Tridens,

Tridens flavus

Other common name(s):

Redtop Tridens, Tall Redtop Tridens, Purpletop, Redtop, Tall Redtop

Family:

Poaceae (Grass Family)

Plant Ecoregion Distribution Map

Cross Timbers, East Central Texas Plains, Edwards Plateau, Gulf Coast Prairies and Marshes, High Plains, Southwestern Tablelands, Texas Blackland Prairies, Western Gulf Coastal Plain
Carbonate Cross Timbers, Eastern Cross Timbers, Grand Prairie, Limestone Cut Plain, Western Cross Timbers
Bastrop Lost Pines, Floodplains and Low Terraces2, Northern Post Oak Savanna, Northern Prairie Outliers, San Antonio Prairie, Southern Post Oak Savanna
Balcones Canyonlands, Edwards Plateau Woodland, Llano Uplift
Coastal Sand Plain, Floodplains and Low Terraces4, Laguna Madre Barrier Island and Coastal Marshes, Mid-Coast Barrier Islands and Coastal Marshes, Northern Humid Gulf Coastal Prairies, Southern Subhumid Gulf Coastal Prairies, Texas-Louisiana Coastal Marshes
Llano Estacado, Shinnery Sands
Canadian/Cimarron Breaks
Floodplains and Low Terraces1, Northern Blackland Prairie, Southern Blackland Prairie
Flatwoods, Floodplains and Low Terraces3, Pleistocene Fluvial Terraces, Red River Bottomlands, Southern Tertiary Uplands, Tertiary Uplands

Plant Characteristics

Growth Form

Grass & Sedge

Height

2.5
to
7
ft.

Spread

1
to
2
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Loam, Dry

Light Requirement

Part Shade

Water Requirement

Low

Native Habitat

Grassland, Woodland

Bloom and Attraction

Bloom Color

Purple

Bloom Season

Summer, Fall

Seasonal Interest

Seeds, Nectar, Larval Host, Nesting Material

Wildlife Benefit

Butterflies, Birds, Small Mammals

Maintenance

Protect from browsers as it is readily eaten during early growth.

Comments

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. In the wild it is common but infrequent. I grows mainly on sandy soils in woodlands sites. Provides seeds for birds and rodents. Larval Host: Cross-line skipper, Broad-winged skipper, Little Glassywing skipper, Large Wood Nymph

References

1) https://www.wildflower.org/gallery/species.php?id_plant=TRFL2, 2) https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=42227#null, 3) http://bonap.net/TDC/Image/Map?taxonType=Species&taxonId=19112&locationType=County&mapType=Normal, 4) https://portal.torcherbaria.org/portal/taxa/index.php?taxon=Tridens+flavus&formsubmit=Search+Terms, 5) Hatch, Umphres, Ardoin, 2015, Field Guide to Common Texas Grasses, pg 282