Blackbutt Peppermint (Eucalyptus smithii RT Baker) is an arboreal species belonging to the Myrtaceae family.
From a systematic point of view it belongs to:
Species E. smithii.
The term is synonymous:
– Eucalyptus viminalis pedicellaris H.Deane & Maiden.
The term Eucalyptus comes from the Greek ἐῧ éu true, well, to perfection and κᾰλυπτός kalýptos to cover, hide: for the lobes of the chalice and the joined petals they form a cap that completely encloses the closed buds.
The specific epithet smithii should be in honor of the American botanist Jared Gage Smith (1866-1925) who herbalized in the USA, Mexico, Australia and Europe.
Geographic Distribution and Habitat –
Eucalyptus smithii is a tree endemic to south-eastern Australia, on sloping sites on the coast and on the highlands south from Yerranderie in New South Wales to eastern Victoria.
Its habitat is that of shallow soils on sloping sites, plateaus and escarpments, at altitudes of up to 500 meters.
Eucalyptus smithii is an evergreen tree with a dense crown that can grow up to 45 meters in height.
The trunk is short and sturdy with a rough and compact bark on the trunk, a smooth and sinewy bark above which is dark gray to black in color.
The leaves of young plants, when these are in the initial sapling stage, are arranged in opposite pairs, green to greyish, narrow in the shape of a spear, 50-110 mm long and 6-25 mm wide, with their bases tightening the stem. The adult leaves are arranged alternately, the same shade of a slightly glossy green color on both sides, from narrow spear-shaped to curved, 60-210mm long and 7-16mm wide, with the base tapering to a petiole 5–28 mm long.
The white flowers are arranged in the axils of the leaves in groups of seven on an unbranched peduncle 5–13 mm long; individual shoots are on 1–6 mm long peduncles. Ripe buds are diamond-shaped oval in shape, 4-6 mm long and 3-4 mm wide with a conical beaked operculum.
The flowering period is from December to January.
The fruit is a cup-shaped, bell-shaped or hemispherical woody capsule 3–6 mm long and 4-8 mm wide with the valves protruding strongly over the edge.
Eucalyptus smithii is a plant widely cultivated in southern Africa and its leaves are used for the production of eucalyptus essential oil.
This plant grows, in its natural habitat, in a climate with an average annual rainfall of 750 to 1,250 mm and a dry season which is normally up to 3 months. The average maximum temperature of the warmest month is 22 – 28 ° C; the average minimum temperature of the coldest month is 2-9 ° C, and generally zero to 20 frosts occur per year.
When the plant is inactive, it can survive temperatures as low as about -10 ° C, but the growth of young specimens can be endangered at -1 ° C.
It is a plant that requires a sunny position, in a medium-textured, well-drained soil of high to moderate fertility. It prefers a pH between 5.5 and 7, tolerating values of 5 – 7.5.
The plant develops from a woody tuber that begins to develop near the base of seedlings and can become massive in mature plants of some species. It has built-in vegetative buds, which allow the plant to regenerate after the destruction of the crown, for example after a fire.
This eucalyptus species has not adopted a deciduous habit and continues to grow until it is too cold to do so. This makes it more susceptible to damage from sudden colds. If temperature changes are more gradual, such as in a forest, the plants have the opportunity to stop growing and become dormant, thus making themselves more resistant to cold. The use of natural mulch around the roots can prevent the soil from freezing, helping the trees to survive the cold as well.
This species, like other congeners, are remarkably adaptable and there can be a noticeable increase in the resistance of subsequent generations, produced from seed and grown in temperate zones.
The propagation of this eucalyptus occurs by seed, with surface sowing that must be done in the period of late winter – early spring in a sunny position in a greenhouse.
Plants that come from high altitudes appreciate a cold stratification of 6 – 8 weeks at 2 ° C.
The transplant should be performed in early summer, giving young seedlings some protection from the cold in their first winter. The seed can also be sown in early summer; in this case young seedlings are planted in their final positions in the late spring of the following year. The seed has a long vitality.
Customs and Traditions –
Eucalyptus smithii is a tree that is harvested in its natural state for its wood and essential oil.
It has been cultivated experimentally as timber crop and for the production of eucalyptus essential oil in Brazil, Guatemala and Zaire.
This plant gives good timber production and is useful for honey production.
The lower bark, quite fragrant, easily detaches from the tree.
The plant is used for medicinal purposes; in fact it uses its essential oil, obtained from the leaves, which is used in aromatherapy.
Crushed leaves are also a good source of essential oil. From these we obtain an essential oil whose total quantity and composition can vary widely from plant to plant; there are reports with data in which fresh leaves contain about 1.1 – 3.0% essential oil. The main component is cineole (about 75-81%), plus pinene, eudesmol and globulol.
The essential oil obtained from the leaves is used as an ingredient in commercial cosmetic preparations for perfumes and other products.
In aromatherapy it is used to stimulate breathing, relieve cough, help expel mucus, relax respiratory muscles and as an adjunct in the treatment of bronchitis, asthma, phlegm, sinusitis and throat infections.
This plant shows interesting uses in the pulp industry which, among other things, is occasionally used for milling and wood chips.
Method of Preparation –
Eucalyptus essential oil is obtained from steam distillation of the leaves and young twigs of Eucalyptus smithii. Approximately 55 kg of leaves and branches are needed to obtain 1 kg of essential oil.
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Treben M., 2000. La Salute from Farmacia del Lord, Advice and experiences with medicinal herbs, Ennsthaler Editore.
Caution: Pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not represent in any way a medical prescription; therefore no responsibility is taken for their use for curative, aesthetic or food purposes.