Glechoma longituba Demystified: The Ultimate Plant Care Handbook

Glechoma longituba, also known as coinwort, round-leaf chervil, thorough-bone herb, wall-penetrating mint, sterol bone wind, barbarian grass, wild mint, wall-piercing grass, clustered herb, wind grass, lungwind herb, coin mint, eighteen imperfections, Jiangsu coinwort, string-of-coins, square thunder god root, horse hoof tendon and bone grass, broken copper coins, opposite-leaf coinwort, child’s rash herb, burrowing wind, and bone-joining vanish, belongs to the Lamiaceae family, Glechoma genus.

This perennial herbaceous plant has creeping stems that root at the nodes as they ascend. The stems, reaching 10-20 (30) centimeters in height, are quadrangular, typically showing a light purple-red color at the base, almost hairless, with the younger parts sparsely covered in elongated soft hairs.

It has a spicy taste and cool nature, suitable for both oral consumption and external application, with benefits including promoting diuresis to alleviate strangury, clearing heat and detoxification, and dispersing blood stasis to reduce swelling.

I. Morphological characteristics

This perennial herbaceous plant has creeping stems that ascend and root at each node. Stems are 10-20 (30) cm high with a quadrangular shape, and they are usually pale purplish-red at the base, almost hairless, with sparse long soft hairs on the tender parts.

The leaves are herbaceous in texture, with the lower ones being smaller, heart-shaped or nearly reniform, and having petioles 1-2 times the length of the leaf blade; the upper leaves are larger, heart-shaped, 1.8-2.7 cm long, 2-3 cm wide, with an acute or blunt apex, and a heart-shaped base.

The margins feature round teeth or coarse serrated round teeth, and the leaves are sparsely covered with coarse appressed hairs or fine soft hairs.

The veins are not prominent, often purplish underneath, with sparse soft hairs or long stiff hairs, usually only along the veins, which are raised. The petioles are 1.5 times the length of the leaf blade and covered with long soft hairs.

The verticillasters usually have two flowers, but occasionally four to six; the bracts and bracteoles are linear, up to 4 mm long, fringed with hairs.

The calyx is tubular, 9-11 mm long, with long soft hairs on the outside, especially along the ribs, and is slightly hairy on the inside.

There are five teeth, with the upper lip having three longer ones and the lower lip having two shorter, egg-shaped triangular teeth, half the length of the calyx, with awn-like tips and fringed edges.

The corolla is pale blue, blue to purple, with dark spots on the lower lip. The corolla tube is erect, gradually expanding into a bell shape at the top.

It comes in a long-tubed form, 1.7-2.2 cm long, and a short-tubed form, usually hidden within the calyx, 1-1.4 cm long, with long soft hairs and fine soft hairs on the outside, and sparse soft hairs or almost hairless on the lower lip on the inside.

The corolla limb is bilabiate, with the upper lip erect and bifid, with nearly reniform lobes, and the lower lip extended and obliquely spreading, trifid, with the middle lobe being the largest and kidney-shaped, 1-2 times the size of the upper lip lobes, with an indented apex, and lateral lobes being oblong, half the width of the middle lobe.

There are four stamens, hidden and hairless, with the rear pair located beneath the upper lip and being longer, and the front pair located beneath the side lobes in the middle of the corolla tube and being shorter; the anthers are two-chambered and slightly divergent.

The ovary is four-lobed and hairless. The nectar disc is cup-shaped, slightly oblique, with the front resembling a finger-like swelling. The style is slender and hairless, slightly protruding, with an almost equally bifid tip.

The mature nutlets are dark brown, ellipsoid-ovate, about 1.5 mm long, about 1 mm wide, with a rounded top, a slightly trigonous base, and are hairless, with an inconspicuous scar. The flowering period is April to May, and the fruiting period is May to June.

II. Growth Environment

This plant thrives in moist, shaded areas such as forest edges, light woodlands, grasslands, and stream banks, at elevations of 50-2000 meters.

III. Distribution Range

It is distributed in Russia and Korea.