WildBristol.uk - Discovering Wildlife in Bristol

Corn Mint x Water Mint x Spear Mint (Mentha arvensis x M. aquatica x M. spicata = M. x smithiana). Widespread and scattered throughout the UK. Habitat includes: Damp to wet places (sometimes thrown out) such as gardens, parks, allotment, churchyards, wasteland etc. Growing habit: Rhizomatous Perennial. Height: Up to 1.5 m. Flowers: July to October. First recorded in the wild in 1724.

Stace 4:

Mentha x smithiana R.A. Graham (M. arvensis x M. aquatica x M. spicata) - Tall Mint.

Plant subglabrous, usually red-tinged, with Spearmint scent; stems erect to scrambling, to 1.5m; leaves ovate, rounded to broadly cuneate at base, with sharp, forward-directed teeth, petiolate; whorls in leaf-axils; calyx narrowly bell-shaped to more or less tubular, with acuminate, narrowly triangular teeth; corolla lilac; usually sterile; 2n=120. Neophyte-naturalised; damp places and waste ground, perhaps sometimes arising as M. x verticillata x M. spicata, but usually escape or throwout; scattered more or less throughout Britain, Central and Southern Ireland, Jersey; ?garden origin.

Key:

• Calyx 2.5-4mm, including teeth usually ≥1mm, the tube about 2x as long as wide

• Plant subglabrous; calyx mostly >3.5mm; stamens usually exerted