Crimson clover, scientifically known as Trifolium incarnatum, is an annual legume recognized for its distinctive appearance. Identifying this plant relies on observing visual characteristics that distinguish it from other clovers. These markers include the unique structure and color of its inflorescence, the texture and shape of its leaves and stems, and its overall growth habit. It is often cultivated as a cover crop or found naturalized along roadsides. The dense spike of flowers is the plant’s most celebrated feature.
The Defining Crimson Flower Head
The most remarkable feature is the singular, elongated inflorescence that terminates each stem. This flower head exhibits a deep crimson to bright scarlet color, which is the source of the plant’s common name. The inflorescence is densely packed with numerous individual florets, often numbering up to 125 per head.
The bloom is cylindrical-ovoid or conical, resembling a pointed, bright red candle. These flower heads typically measure between one and two and a half inches in length and are about half to three-quarters of an inch wide. Each tiny, pea-shaped flower within the spike is oriented upward, contributing to the overall fuzzy or velvety appearance of the mature flower head.
Flowering progresses sequentially, with the lower florets opening first, followed by those moving upward toward the tip. This pattern ensures a prolonged display of its characteristic deep color, usually from late spring into the early summer. The vivid color and spike-like structure make the plant a reliable field identifier during its peak season.
Identifying Features of the Leaves and Stems
The vegetative parts of the plant offer further clues for identification. The leaves are compound, arranged in the trifoliate pattern typical of clovers, consisting of three leaflets. These individual leaflets are broadly oval or obovate in shape, often described as heart-shaped, and are rounded at their tips.
Each leaflet is generally about half an inch to over an inch long and may have edges that are smooth or very finely toothed. The upper surface is a dull medium green, and unlike some related species, the leaflets do not typically display a white, V-shaped marking.
A distinguishing textural feature is the dense covering of soft, long hairs, or pubescence, that blankets the entire plant. These hairs are noticeable on the leaf surfaces, the leafstalks (petioles), and the stems, giving the plant a fuzzy feel. The stems are often light green, though they can become slightly reddish-brown near the base.
Growth Pattern, Size, and Habitat
Crimson clover is classified as an annual, meaning it completes its life cycle within a single year, though it often acts as a winter annual in milder climates. The plant grows with a mostly erect and bushy habit, frequently forming dense, upright stands in cultivated fields.
The mature height ranges from about one to three feet tall. Its stems are generally unbranched or only branch near the base, contributing to its upright stature.
The plant is commonly found in disturbed areas, along roadsides, and in pastures, thriving across a wide range of temperate zones. It shows a preference for well-drained soils, tolerating conditions from sandy to clayey, and is widely utilized in agriculture as a cover crop.