Lemon balm (Melissa officinalis) is a perennial herbaceous plant in the mint family.
{| class="wikitable sortable"
|+ Composition of oil
|-
! Component !! minimum % !! maximum %
|-
| Methyl Heptenone || 2.2 || 8.6
|-
| Citronellal || 1.0 || 8.4
|-
| Linalool || 0.5 || 2.7
|-
| Neral || 19.6 || 36.1
|-
| Geranial || 25.3 || 47.5
|-
| Geranyl acetate || 1.2 || 6.2
|-
| Carophyllene || 1.9 || 9.7
|-
| Carophyllene oxide || 0.5 || 9.0
|}
Etymology
The white flowers attract bees, hence the genus Melissa (Greek for "honey bee"). It is not to be confused with bee balm (genus Monarda).
The second name, officinalis (Latin, 'of the shop'), originates from the use of the herb by apothecaries, who sold herbal remedies directly to their customers.
Distribution and habitat
thumb|A bumblebee feeding on a lemon balm flower
Melissa officinalis is native to south-central Europe, the Mediterranean Basin, Central Asia and Iran, but is now naturalized in the Americas and elsewhere around the world. It grows easily from seed, preferring rich, moist soil.
Cultivation
Lemon balm seeds require light and a minimum temperature of to germinate. The plant grows in clumps and spreads vegetatively (a new plant growing from a fragment of its parent), as well as by seed. In mild temperate zones, the plant stems die off at the start of the winter, but shoot up again in spring. Lemon balm grows vigorously.
, Hungary, Egypt, and Italy are the major producing countries of lemon balm. The leaves are harvested by hand in June and August in the northern hemisphere, on a day when the weather is dry, to prevent the crop from turning black if damp.
The cultivars of M. officinalis include:
- M. officinalis 'Citronella'
- M. officinalis 'Lemonella'
- M. officinalis 'Quedlinburger'
- M. officinalis 'Lime'
- M. officinalis 'Mandarina'
- M. officinalis 'Variegata'
- M. officinalis 'Aurea'
- M. officinalis 'Quedlinburger Niederliegende', a variety reportedly bred for higher essential oil content.
Essential oil production
Ireland is a major producer of lemon balm essential oil, which has a pale yellow colour and a lemon scent. The essential oil is commonly co-distilled with lemon oil, citronella oil or other essential oils. Yields are low; 0.014% for fresh leaves and 0.112% for dried leaves.
thumb|The plant seen in visible light, [[ultraviolet light and infrared]]
Uses
Lemon balm is used as a flavouring in ice cream and herbal teas, often in combination with other herbs, such as spearmint.
In traditional Austrian medicine, M. officinalis leaves have been prescribed as an herbal tea, or as an external application in the form of an essential oil.