In some respects Facelis retusa, known as Trampweed, is a typical weed: a non-native, broadleaf winter annual that came to us from South America. The term “weed” typically carries with it the connotation of a sprawling, undisciplined, rank and irregular plant. But Facelis retusa is an exception to the majority, having a highly organized and regular growth form and pattern.
As seen in the photo below, seedling Trampweeds are about an inch across and have the regular, pinwheel or pinecone shape that they retain until they bloom. The leaves are short and blunt, are wider at the tip than at the base, and end in a sharp point. Trampweeds are also floccose, a botanical term meaning covered with tufts of white, wooly hairs – illustrated below.
Trampweeds often grow in clusters and tend to form colonies that merge into each other.
Below is a larger plant formed by the growth and branching of at least two individual plants.
Colonies continue to grow and branch, and will eventually merge together into mats 3 or 4 feet across if left undisturbed.
Horticultural sedums sometimes have a similar form, making it difficult to recognize that invading Trampweeds are present. A garden sedum is shown below.
Facelis retusa is a member of the aster family, the Asteraceae, and has flowers typical of many members of that family. The flower petals (the ray flowers) are absent, so the plants have only the disk flowers, which are small and delicate and resemble miniature paint brushes. After the bloom the tiny seeds (achenes), attached to fine hairs, blow away in the breeze. Tufts of fine, cottony hair can be seen on the ground around plants that are discharging seeds.
Trampweeds are very common in the Falls Lake area. All of the photographs were taken at the Falls Lake Dam, overlooking Falls Lake, or in the nearby area. In an odd anomaly, distribution maps do not list Facelis retusa in any of the Falls Lake counties or the counties surrounding them. The best explanation for this may simply be a lack of interest; no impetus to trigger the documentation of a new county plant.