- Family: Mint Family – Lamiaceae (Labiatae)
- Growing form: Perennial herb. Root partly tuberous.
- Height: 50–100 cm (20–40 in.). Stem 4-edged, dark red.
- Flower: Corolla irregular (zygomorphic), light red–purple, 15–20 mm (0.6–0.8 in.) long, fused, bilabiate. Upper lip convex, hairy, tipped by white tuft; lower lip 3-lobed. Calyx regular (actinomorphic), 5-lobed. Stamens 4, of which 2 short, 2 long. Gynoecium composed of 2 fused carpels. Flowers in whorls forming a lax interrupted spike.
- Leaves: Opposite, basal leaves long-stemmed, stem leaves stalkless. Basal leaf blade ovate, cordate-based, underside hairy, sparsely haired on top, with rounded teeth; stem leaves’ blade smaller, ovate–elliptic, shallowly cordate-based. Subtending bracts lanceolate, much longer than flowers.
- Fruit: 4-parted schizocarp.
- Habitat: Roadsides, railway yards, waste ground, parks.
- Flowering time: June–July.
Jerusalem sage is an exotic sight in Finland. The species’ original habitat stretches from central Europe to south-west Asia and Siberia where it grows on dry steppes, meadows and rocky land. In the north is has for some reason or other made itself at home only in Finland, and it is a rare phenomenon here. It has been observed growing as far north as Oulu as an escape from gardens and an alien that grows from seed. The species’ permanent habitat is however much further south: this cultural plant is most easily found along roadsides, in earth heaps and on the edges of forests in the more urbanised south of Finland. It is best to leave plants that are growing wild where they are – if they would look good in the garden it’s better to buy them from a plant shop. With its light lilac/rose-red flowers Jerusalem sage is a nice addition in a perennial flower bed in sunny places, and it also makes a good cut flower. Rigid, reddish stems survive through the winter after withering, or they can be cut in the summer with the infructescence to make lovely cut flowers.
In Finland the only genus Phomis species that has been experimented with as a perennial is Jerusalem sage, but there are bound to be others that are able to withstand the Finnish climate.