Uniquely identifiable characteristics : rub the leaves and smell the wonderful aroma. No other plant produces a smell quite like this one does. Describing a small is fairly difficult, but you'll know you've seen bog myrtle when you smell this.
Distinguishing Feature : The short knobbly woody stem and the dark-green lanceolate leaves. Your feet will likely be very wet too, for you will be standing in a bog!
Lookee-Likees : At first glance, Bog-myrtle could be mistaken for a small Rhododendron or
No relation to :
Chilean Myrtle (Luma Apiculata).
Bog-myrtle grows only in wettish peaty soils typical of upland acidic bogs where nitrogen levels are low; but it has nitrogen-fixing Frankia-genus actinobacteria within its root system and is thus able to fix atmospheric nitrogen from the air which allows it to flourish in this nitrogen-poor environemt. Bog Myrtle is one of the few plants capable of this feat apart from the well-known ability of certain members of the Pea Family (Fabaceae) which can also accomplish this task..
An entrancing sweet-smelling resin comes in evidence when the leaves are crushed between the fingers. A large straggle of Bog Myrtle in the sodden hills can be smelled from half a mile away. It is wind-pollinated, the pollen being allergenic.
Bog Myrtle has quite a reputation for repelling midges and fleas, and has been used many times in the past and even recent past for such duty, no doubt due to the odorous resin. A midge repellent called 'Myrica' made by steam distilling the volatile oil from Bog Myrtle was sold by a Scottish company in the Isle of Skye. It was found to be very effective on Scottish midges (Culicoides impunctatus).
But it has an even bigger reputation as a substitute for hops in brewed alcoholic beverages. If ever your author were to brew a beer made from Sweet Gale, he would name the beer Regale! There is a Scottish brewery, Fraoch, that is brewing a Heather Ale using Heather and Bog Myrtle from the extensive crops on Scottish bogs. It is reportedly an abortifacient, so pregnant women should avoid drinks and condiments containing Bog Myrtle.
The flowers are borne in catkins, the male are orange and angled upwards, the female are red and drooping; it is (usually) dioecious with male and female flowers on separate plants, but occasionally monoecious with both male and female flowers (catkins) on the same plant. Individual plants are also known to have changed sex from year to year. There are only photos of the male sex here, I need photos of the female plants with flowers.
A yellow dye which used in tanning can be extracted from Bog Myrtle.
It was a traditional medicine with uses against parasites and to treat skin disorders, to treat gonorrhea and as a diuretic.
It may or may not be related to
Bayberry (Morella caroliniensis) and
Wax Myrtle (Morella cerifera) which may yet be transferred to the Myrica genus.
A fragrant wax can be obtained from the fruits of
Candle Berry) (Myrica pensylvanica) (formerly Myrica cerifera) which burns with a fragrance. This is an introduced and naturalised plant planted for ground cover for birds which is naturalised on wet heathland in Hampshire (both North and South).
Both leaves and fruits are covered in glands which secrete a resinous and fragrant substance.
Myrtenol is the resinous substance in Bog-Myrtle responsible for its pleasant aroma and its insect repellent and beverage flavouring properties. As can be seen it is chemically related to Verbenol, another terpene which is found in some species of Verbena plants (Vervain), and in turpentine, a solvent for good paints. Both have the configuration, if not the structure, of
cubane. α-Pinene is also present as an aroma compound, being Verbenol without the extra -OH group.
Bog Myrtle also contains Eucalyptol (aka 1,8-Cineole), which contributes to the resinous smell. Eucalyptol, obtained as an essential oil from Eucalyptus Trees, is also used in cough medicine and throat lozenges for its refreshing and cool sensations and some cigarettes which in the 1960's were claimed to be 'as cool as a mountain stream', but doses are small for it is toxic in higher concentrations. It is used to treat nasal obstruction and asthma.
The essential oil also contains several other MonoTerpenes and Sesquiterpenes as major components: α-Pinene,
γ-Cadinene, Caryophyllene, Myrcene, Limonene,
1,8-Cineol. The Germacrenes, of which versions A to E are known, are insecticidal sesquiterpenes produced by a number of plants, some also playing a role as insect pheromones; the most ubiquitous are
Germecrene A and Germacrene D;
Germacrene B is not common. Bog Myrtle also contains the
Myricetin, a flavonol flavonoid similar to Quercetin, is also found not only in Bog Myrtle but also in grapes, berries, fruits, herbs and vegetables. It exhibits anti-septic properties, and it was found it can also lower the incidence of prostrate cancer. Being a flavonol Myricetin has a deep-yellow colouration unlike the usual paler yellow colour of Flavones. The three commonest plant flavonols are Kaempferol,
Quecetin amd Myricetin.