Manual of the New Zealand Flora.
[Introduction to Order LIX. LabiatÆ.]
Herbs or shrubs, the stems and branches usually quadrangular. Leaves opposite or whorled, frequently replete with glands containing an aromatic volatile oil; stipules wanting. Flowers hermaphrodite, irregular, solitary or in small axillary opposite cymes or clusters which are often aggregated into terminal spikes or racemes. Calyx inferior, persistent, 4–5-toothed or -cleft, or 2-lipped. Corolla gamopetalous, hypogynous; limb more or less 2-lipped, rarely equal; lobes 4–5, imbricate. Stamens inserted on tne corolla-tube, usually 4 and then often didynamous, sometimes 2 only; anther-cells separate or confluent. Ovary superior, of 2 connate deeply 2-lobed carpels and hence 4-partite, 4-celled; style simple, proceeding from between the lobes of the ovary; stigma usually 2-fid; ovules solitary in each cell, erect, anatro-pous. Fruit enclosed in the persistent calyx, of 4 1-seeded nutlets. Seeds small, erect; albumen wanting or nearly so; radicle next the hilum.
A very large and exceedingly natural family, quite cosmopolitan in its distribution, but most abundant in the warm-temperate portion of the Northern Hemisphere. Genera close upon 150; species not far from 2600. Most of the species are strongly aromatic, and have stimulating or tonic properties. Some are used as condiments, as thyme, spearmint, sage, marjoram, sweet basil, &c. The essential oils obtained from peppermint, lavender, rosemary, and other species are used medicinally. Many brilliant garden-plants belong to the order, especially of the genus Salvia. The meagre representation of the family in New Zealand is one of the chief peculiarities of the Flora. Only 2 genera occur, both of which have a wide distribution in temperate and warm regions. On the other hand, many species of northern origin have become naturalised since the commencement of European settlement, as will be seen on reference to the list of introduced plants given in the appendix.
Calyx 10-nerved. Corolla almost regular, lobes flat. Stamens 4, equal, erect 1. Mentha. Calyx 2-lipped, closing over the fruit. Corolla 2-lipped. Stamens 4, didynamous 2. Scutellaria.