BALM

LEMON BALM

Melissa officinalis

Mint / Dead-Nettle Family [Lamiaceae]

month8jul month8july month8aug month8sep month8sept month8oct

status
statusZneophyte
 
flower
flower8white
 
inner
inner8lilac inner8pink
 
morph
morph8zygo
 
petals
petalsZ2 petalsZ5
2 (5)
type
typeZtieredwhorls
 
stem
stem8angular
 
smell
smell8lemon
lemon

19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Grown in gardens as both a culinary and medicinal herb, from where it frequently escapes.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
More closely resembles Gipsywort with its whorls of small in-conspicuous white flowers.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Flowers quite small, 8-15mm in length, and quite inconspicuous.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Mint-like leaves in opposite pairs in quadrature up the square to angular stem. Whorls of flowers just above leaf pairs, quite separated. Here the flowers themselves have been and gone, just leaving the empty sepal tubes.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Flowers, small, white to pale lilac or pink, with an upper part and a longer lower lip, emerging from the green sepal tubes.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Leaves yellowish-green at first, oval, toothed and wrinkled; the veins particularly prominent on the underside.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Whorls often in-complete, not in a full circle. Flowers have 2 petals, with 5 lobes. Hairy sepal tubes with five short pointed teeth.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Sepal tubes hairy, zygomorphic, and with short teeth. Stems square to angular.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Sepal tubes have bi-lateral symmetry with three short points on the upper teeth, and two longer points on the lower two teeth.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Flowers have a large lower lip which curls downwards, two side lobes angled downwards, and a nicked upper cowl.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Lower lip of flower has a hairy throat.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Leaves oval, toothed, wrinkled, opposite each other on stalks and smell of lemon when crushed.


19th Aug 2011, Cragg Vale, West Yorkshire. Photo: © RWD
Obverse of leaves have prominent veins.


Not to be semantically confused with : Bastard Balm [a plant with similar name but which also belongs to the same dead-nettle Family] nor with Melilotus officinalis (Ribbed Melilot).

Some similarities to : Gipsywort but those leaves do not smell of lemons when crushed. Also, the leaves of Balm are oval, whilst those of Gypsywort are much longer than wide.

Uniquely identifiable characteristics

Distinguishing Feature : the unexpected smell of lemons when the leaves are crushed.

No relation to : Lemons [a tropical tree bearing yellow fruit with similar name].

The only plant (at least in the UK) belonging to the Melissa Genus, although there are many cultivars. It is not known whether the above photos are a cultivar, but they were growing on a public right of way within the grounds of a house. It is a perennial herb.

Balm, or Lemon Balm, contains Eugenol and numerous other terpenes and their derivatives. Specifically 1-octen-3-ol, 10-α-cadinol, 3-octanol, 3-octanone, α-Cubebene, α-humulene, β-Bourbonene, Caffeic Acid, Caryophyllene, Caryophyllene-oxide, Catechinene, Chlorogenic acid, Cis-3-hexen-1-ol (leaf alcohol, which has an intense grassy-green odour of freshly cut grass), cis-Ocimene, Citral-A, Citral-B, Citronellal, Copaene, Eugenyl-acetate, γ-Cadinene, δ-Cadinene, Geranial, Geraniol, Geranyl Acetate, Germacrene D, Isogeranial, Linalool, Luteolin-7-glucoside, Methyl-heptenone, Neral, Nerol, Octyl-benzoate, Oleanolic Acid, Pomolic acid, Protocatechuic acid, Rhamnazine, Rosmarin acid, Rosmarinin acid, Stachyose, Succinic Acid, Thymol, Trans-Ocimene and Ursolic Acid. Strangely, it lacks Limonene which smells of oranges but which is present in the peel of Lemons.

LEMON SCENTED MONOTERPENOIDS


The leaves not only smell lemony, but also have a citrusy taste like the non-native Lemongrass. Balm is used to flavour ice-creams and herbal teas. Its flavour derives from four of the main constituents of the essential oil from Lemon Balm: 24% Citronellal, 16% Citral, 12% Linalyl Acetate (aka Bergamiol, Bergamol and Linalool Acetate) and 12% Caryophyllene. Citral has two conformational isomers, the (E)-isomer is known as Citral A aka Geranial, the (Z)-isomer as Citral B aka Neral. Shown is Citral A, Geranial, which has a strong lemon odour (the odour of Citral B, Neral is less intense). It is used in perfumery whenever a hint of citrus is required and is present in the essential oil of the non-native? Lemon Myrtle (Backhousia citriodora) at a whopping 90-98%, in Lemongrass (Cymbopogon citratus) at 65-85%, in Balm/Lemon Balm at just 11%, Lime fruits at 6-9% and Lemon fruits at 2-5%.

Citronellal (aka Rhodinal) also smells of lemon fruits and it too is a major component of Lemongrass (Cymbopogon citratus) and other plants that smell of lemons. It is a highly effective repellent of mosquitoes and also has strong anti-fungal properties.

MINTY SCENTED MONOTERPENOIDS

Linalyl Acetate has a taste similar to its fruity minty smell. It is the Acetate of Linalool which it usually occurs in plants together with, and is a major component in Lavender.


  Melissa officinalis  ⇐ Global Aspect ⇒ Lamiaceae  

Distribution
 family8Mint / Dead-Nettle family8Lamiaceae

 BSBI maps
genus8Melissa
Melissa
(Balm)

BALM

LEMON BALM

Melissa officinalis

Mint / Dead-Nettle Family [Lamiaceae]

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