Check the leaf pairs
Opposite leaves are one of the quickest clues. Look for two leaves arising at the same level on opposite sides of the stem.
Self-heal
Prunella vulgaris
Family: Lamiaceae
Flowering: June, July, August, September, October
Plant family guide
Start with Self-heal
Self-heal (Prunella vulgaris) is a widespread British member of Lamiaceae. Its compact purple flower heads, opposite leaves and four-angled stem provide a useful introduction to the family.
The mint family includes familiar culinary herbs such as mint, thyme and marjoram, but also many wildflowers including dead-nettles, woundworts, bugle and Self-heal. Many members are aromatic, although this is not true of every species.
Key family attributes
- Stem: herbaceous members commonly have four-angled or apparently square stems. Feel or rotate the stem gently rather than relying only on appearance.
- Leaves: usually simple, without stipules, and arranged in opposite pairs. Successive pairs often sit at right angles to one another.
- Flowers: the petals are fused into a tubular corolla, commonly with a hooded upper lip and a broader lower lip. This two-lipped form is called bilabiate.
- Stamens: commonly four, often arranged as two longer and two shorter stamens, although some genera have only two.
- Ovary and fruit: the ovary is deeply four-lobed and usually develops into four small one-seeded nutlets. The style often rises from between the lobes.
- Scent: many members contain aromatic oils, giving mints, thymes and marjorams their familiar scent, but lack of a strong smell does not rule out Lamiaceae.
Features to look for in the field
Look at the flower lips
Many mint-family flowers have a hood-like upper lip and a lower lip that acts as a landing platform for pollinating insects.
Turn the stem
A four-angled stem strongly supports a mint-family identification when it occurs together with opposite leaves and bilabiate flowers.
Look closely at Self-heal
- Flower head: short, dense and terminal, with flowers emerging from overlapping green to purplish bracts.
- Leaves: opposite and broadly oval to lance-shaped, usually with nearly smooth or only shallowly toothed margins.
- Growth habit: low and often spreading through short grass, lawns, verges and meadow turf.
- After flowering: the persistent bracts darken to purplish-brown, leaving a distinctive old flower head.
Other British members to compare
Once you recognise the family pattern, compare Self-heal with Bugle (Ajuga reptans), Red Dead-nettle (Lamium purpureum), Hedge Woundwort (Stachys sylvatica) and Water Mint (Mentha aquatica).
Their overall shapes differ considerably, but opposite leaves, four-angled stems and two-lipped flowers recur often enough to make Lamiaceae one of the more rewarding families to learn in the field.
Lamiaceae flowers in this guide
Explore the individual flower pages for more photographs and identification details.