Catnip, scientifically known as Nepeta cataria, is a well-recognized member of the mint family, Lamiaceae, and is famous for the temporary euphoric effect it has on many domestic cats. This perennial herb is native to parts of Europe and Asia but is now widely naturalized. For people looking to identify the fresh plant, a clear understanding of its distinct physical appearance is necessary to distinguish it from other green plants.
Key Visual Characteristics of the Plant
The foliage of fresh catnip provides the most immediate visual cues for identification. The leaves are generally triangular to ovate, with a characteristic heart-shaped base where the leaf meets the petiole or stalk. They feature coarsely toothed or scalloped edges, and the leaves are arranged oppositely along the stem, a common trait in the mint family. Coloration ranges from a bright green to a more grayish-green, which is due to a dense covering of fine, soft hairs.
The stem structure is a defining feature of all mint family members, including catnip. Fresh catnip stems are erect, branched, and distinctly square or four-sided when rolled between the fingers. These stems typically grow to a height of two to three feet, supporting the foliage and flower spikes.
Later in the season, the plant produces small flowers in dense, spike-like clusters at the tips of the stems and from the upper leaf axils. These individual flowers are small, often about a quarter to a third of an inch long, and are usually white or a pale lavender color. They frequently exhibit tiny purple or pink spots on the lower lip of the two-lipped flower structure.
Growth Habit and Preferred Location
Fresh catnip plants grow in a bushy, somewhat rangy habit, forming spreading clumps or patches when left undisturbed. Under ideal conditions, the herb can reach a height of 20 to 40 inches, with a similar spread. Though the plant can tolerate partial shade, it grows best and most vigorously in full sunlight.
Catnip is a hardy and adaptable plant that is often found in disturbed areas. It is commonly seen growing along roadsides, in fields, on waste ground, and along the edges of woods. Once established, it is quite drought-tolerant and can thrive in average to poor, well-drained soil, contributing to its ability to spread and naturalize in many temperate regions.
The Identifying Scent and Texture
Both the leaves and the stems are covered in a fine layer of downy hairs, known as pubescence, which gives the entire plant a soft, fuzzy feel. This layer of hair also contributes to the grayish-green, almost silvery appearance of the foliage, especially on the undersides of the leaves.
The most definitive characteristic is the plant’s potent, musky aroma, which is released when the fresh leaves are crushed or bruised. This distinctive fragrance is due to the volatile oil nepetalactone, which is concentrated in special glands on the leaf surfaces. The scent is often described as green, warm, and slightly minty, but it is less sweet and sharp than other common mint varieties.