Glechoma is a small genus of perennial flowering herbs in the mint family, Lamiaceae, placed within the order Lamiales. The genus was first described for modern science in 1753 and comprises around eight accepted species. Plants in this genus grow as low, spreading herbs with slender stolons that creep along the ground, giving the most familiar species, Glechoma hederacea (ground-ivy or creeping charlie), its common names. Stems may be prostrate or semi-upright and carry leaf blades on long petioles. Flowers are borne in small clusters arising from the leaf axils and feature the tubular, two-lipped corolla typical of the mint family, generally blue-violet in color.
The genus is centered in Asia, particularly China, with representation across northern Asia and Europe. Its closest relative is Meehania, and some species have been transferred between the two genera by different authorities. Glechoma hederacea has spread far beyond its native Eurasian range and is now naturalized across much of North America and New Zealand, where it is considered an invasive weed in many regions.
Etymology
The name Glechoma is said to derive from the Greek glechon, the ancient Greek name for pennyroyal (Mentha pulegium), reflecting the aromatic character shared across related mint-family herbs.
Distribution
Glechoma is native to northern Asia and Europe, with its greatest diversity in Asia, especially China. Individual species are found from Sardinia and southeastern Europe through Russia to Japan, Korea, and Vietnam. Glechoma hederacea has been introduced and is now naturalized across much of North America and New Zealand.
Ecology
Glechoma longituba is visited by the carpenter bee Xylocopa sinensis, which has been recorded robbing nectar from the flowers rather than acting as a conventional pollinator. The genus as a whole is associated with disturbed habitats, woodland edges, and damp grasslands across its native range.
