Citation: L., Sp. Pl. 592 (1753) subsp. officinalis.

Synonymy: Not Applicable

Common name: Balm, common balm.

Description:
Perennial herbs to 1 m high, much-branched with quadrangular branches becoming scarcely woody at the base, more or less densely covered with simple hairs often gland-tipped; leaves with the petiole 1-4 cm long; blade ovate, 2-8 x 1.5-5 cm, truncate to cuneate at the base, usually coarsely serrate, with scattered long simple hairs.

Inflorescence usually a branched thyrse, without a peduncle, with sessile cymose part-inflorescences forming dense clusters of often pedicellate flowers around the nodes and with internodes between them often much elongated, with bracts subtending the part-inflorescences longer than these and leaf-like; sepals unequally connate, 2-lipped, 13-veined, 7-8 mm long, with posterior lip broad and shortly 3-lobed, with antherior lip narrower and deeply 2-lobed, with each lobe sharply pointed, with fine spreading hairs rarely glandular; corolla pale-yellow to pinkish-blue, 2-lipped, with both lips shorter than the tube, 8-12 mm long, glabrous, with posterior lip short and broad, 2-lobed, with anterior lip scarcely longer, with 2 short lateral lobes and the broad anterior one; stamens inserted in about the throat of the corolla tube, with filaments glabrous; anthers with 2 cells fertile and strongly diverging so that they are above one another in a vertical line, born along the posterior lip, glabrous, exposed; ovary on a thick disc, deeply 4-lobed, with a slender style inserted near the base and curved along the posterior lip of the corolla, with a 2-fid stigma.

Mericarps narrowly oblong-obovoid, c. 3 mm long, without keels, with the attachment scar almost circular, basal; finely reticulate-pitted.

	Flowering branch, leaf and calyx.
Image source: fig. 554A in Jessop J.P. & Toelken H.R. (Ed.) 1986. Flora of South Australia (4th edn).

Published illustration: Hegi (1926) Illustrierte Flora von Mittel-Europa 5, 4:fig. 3205.

Distribution:  Grows in moist areas usually along creeks. S.Aust.: NL, MU, SL.   N.S.W.; Vic.; Tas.   Probably native to the eastern Mediterranean but nowadays widely naturalised and cultivated in Europe. Conservation status: naturalised Flowering time: Dec. — March.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: No text

Uses: An ornamental cultivated for its lemon-scented foliage.

Author: Not yet available