Trichostema

Trichostema is a genus of flowering plants in the family Lamiaceae, which are aromatic herbs, subshrubs, or shrubs. These plants are native to North America. Most species in this genus are referred to by the common name bluecurls because of their blue to purple flowers and relatively long, curled stamens.

Plants in the genus Trichostema are either annual herbs, perennial subshrubs, or perennial shrubs. Stems are four-angled, becoming rounder with age in the perennial species. The stems of all species bear glandular and eglandular hairs; these are important for identifying species. Leaves are opposite and simple, though some plants will rarely have leaves with one or two lobes. Flowers are arranged in cymes in the axils of leaves or bracts. Flowers consist of five fused sepals, five petals that are fused at the base, four stamens, and one four-lobed pistil. The individual sepals are either essentially the same length, as in sections Chromocephalum, Isanthus, Orthopodium, Paniculatum, and Rhodanthum, or there are three long and two short sepals, as in section Trichostema. The five petals are typically in the blue to violet color range with the bottom-most petal being white with blue-violet splotches, though Trichostema nesophilum,Trichostema purpusii, and individual plants with floral color mutations are exceptions. Stamens are typically arched to some degree and the same color as the petals, giving rise to their common name. The fruit of the plant is a schizocarp composed of four hard single-seeded mericarps (derived from the four lobes of the pistil), which are called nutlets.