-- In the Wild -- Purpletop Tridens - Texas' impressive purple haze
By Judith Pannebaker BCC Editor
Tridens flavus - aka Purpletop Tridens, Purpletop, Red Top and Greasegrass - is a large, attractive perennial, native to North America in general and, except for the South Texas Plains, the Lone Star State, in particular.
According to one information source, it provides good grazing in the Hill Country - but only after a first frost.
The name Purpletop Tridens is derived from the grass' purple-colored seeds, which are unusual for a grass. Additionally since the seedhead is often covered with an oily substance that attracts dust and dirt, which gives rise to the plant's other common name, "Greasegrass."
It also produces attractive purple spikelets during the late summer, making it easily identifiable. The drooping purple tufts offer a splendiferous sight from mid-summer through early fall, with the blooming period lasting two to three weeks. A perennial, Purpletop grows four to five feet high and can occur as bunchgrass or as scattered individuals.
After blossoming, the spikelets lose their purple color and turn brown.
Fruit and seed production begin in the summer and continue until fall.
The plant does not retain its leaves from year to year.
Because the flowers attract few insects, Purpletop's blooms are wind-pollinated, making the grass best suited for large-scale naturalizations in open woods or fields.
Except for livestock after a frost, few insects and small animals feed on Purpletop Tridens foliage, but its seeds are occasionally eaten by wild turkey and Northern Bobwhite Quail. The grass also provides significant cover for wildlife.
Purpletop Tridens thrives in virtually any type of soil, including those that contain loam, clay-loam, gravel, rocky material and some sand. However, it is typically found on deeper soils.
Habitats include almost anywhere, openings in woodlands, savannas, woodland borders, meadows in wooded areas, powerline clearances in wooded areas, limestone glades, fields and abandoned railroads. Purpletop also thrives in disturbed open areas of woodlands. For this reason, some sources characterize Purpletop as a weed found in hay fields, pastures and abandoned fields.
However, by colonizing in disturbed areas, this plant, as well as other native grasses, are ecologically important because they prevent erosion and soften the soil by penetration with tough, deep, fibrous roots.
This drought-tolerant grass requires no irrigation or fertilizer, but it likes full to partial sunlight.
Purpletop's unusual color is its greatest asset, capping meadows and fields with a lavender tinge. This is an excellent and colorful grass to introduce in natural acreage, but requires large-scale plantings to look its best. Purpletop Tridens is characterized as a fast grower.
It can be propagated by seed or by clump division.
(Sources: en.wikipedia.org, www.illinoiswildflowers.info/, www.ppws.vt.edu/scott/weed_id/trsfl.htm, http://extension.missouri.edu, http://22.214.171.124/resources/wildlifehabitats. www.gardenguides.com and www.fsl.orst.edu)
Photos by Lynn Post