Melissa officinalis L.
lemon balm
Rhizomatous, lemon-scented herb with branched puberulent stems ascending to c. 60 cm. Lvs and bracts petiolate. Lamina 2-8.5 × 1-7 cm, elliptic to broad-ovate, hairy, sometimes only sparsely hairy above, prominently crenate-serrate; base ± truncate in larger lower lvs, cuneate in upper smaller lvs and bracts. Verticels generally 3-10-flowered. Calyx c. 8 mm long; nerves prominent, with long, white, pilose hairs; upper teeth broad-triangular, aristate; lower narrow-triangular, aristate. Corolla 12-15 mm long, white; lobes hairy outside. Nutlets 1.7-2 mm long, almost black.
N.; S.: scattered localities throughout.
Eurasia 1904
Forest margins, scrub and open plantations near roadsides and waste places.
FL Dec-May.
Lemon balm has been widely cultivated in N.Z. since the early period of European settlement. The strongly lemon-scented lvs are used for flavouring and once were used medicinally. Recently, large bushy plants of this sp. lacking the characteristic lemon scent were found in the Kauaeranga Valley, Thames district. They correspond fairly closely to descriptions of subsp. altissima (Smith) Arcangeli which is said to be foetid. However, the Kauaeranga Valley plant is not foetid although the mint-like scent is quite different to the ordinary lemon balm. In addition, these plants match specimens of this subsp. from Turkey at Kew (R. M. Harley, in litt.). subsp. inodora (Bornm.) Bornm. also seems to be morphologically similar but presumably lacks a strong scent. The 3 subspp. are apparently easily confused and Mill, R. R., in Fl. Turk. 7: 262 (1982), suggested that intermediates occur between all 3 subspp., combining one or more key characters.
