| Myrtle (Myrtus communis). | |
| 1. Vertical section of flower, enlarged. | 3. Berry, enlarged. |
| 2. Plan of flower in horizontal plane. |
4. Seed with contained embryo, 𝑒, much enlarged. |
It is a low-growing, evergreen shrub, with opposite leaves, varying in dimensions, but always small, simple, dark-green, thick in texture, and studded with numerous receptacles for oil. When the leaf is held up to the light it appears as if perforated with pinholes owing to the translucency of these oil-cysts. The fragrance of the plant depends upon the presence of this oil. Another peculiarity of the myrtle is the existence of a prominent vein running round the leaf within the margin. The flowers are borne on short stalks in the axils of the leaves. The flower-stalk is dilated at its upper end into a globose or ovoid receptacle enclosing the 2- to 4-partitioned ovary. From its margin proceed the five sepals, and within them the five rounded, spoon-shaped, spreading, white petals. The stamens spring from the receptacle within the petals and are very numerous, each consisting of a slender white filament and a small yellow two-lobed anther. The style surmounting the ovary is slender, terminating in a small button-like stigma. The fruit is a purplish berry, consisting of the receptacle and the ovary blended into one succulent investment enclosing very numerous minute seeds. The embryo-plant within the seed is usually curved. In cultivation many varieties are known, dependent on variations in the size and shape of the leaves, the presence of so-called double flowers, &c. The typical species is quite hardy in the south of England. The Chilean species, M. Ugni, a shrub with ovate, dark green leaves and white flowers succeeded by globular red or black glossy fruit with a pleasant smell and taste, is a greenhouse shrub, hardy in south-west Britain. The common myrtle is the sole representative in Europe of a large genus which has its headquarters in extra-tropical South America, whilst other members are found in Australia and New Zealand. The genus Myrtus also gives its name to a very large natural order, Myrtaceae, the general floral structure of which is like that of the myrtle above described, but there are great differences in the nature of the fruit or seed-vessel according as it is dry or capsular, dehiscent, indehiscent or pulpy; minor differences exist according to the way in which the stamens are arranged. The aromatic oil to which the myrtle owes its fragrance, and its use in medicine and the arts, is a very general attribute of the order, as may be inferred from the fact that the order includes, amongst other genera, Eucalyptus (q.v.), Pimenta and Eugenia (cloves). Myrtol, a constituent of myrtle oil, has been given in doses of 5–15 minims on sugar or in capsules for pulmonary tuberculosis, fetid bronchitis, bronchiectasis, and similar conditions. It appears to lessen expectoration in such cases. The leaves of Myrtus chekan are aromatic and expectorant, and have been used in chronic bronchitis.