Alternative names: Not Applicable

Description:
Shrubs or usually herbs, often with a root stock or rhizome, mostly with quadrangular branches, usually aromatic; leaves opposite, rarely whorled, exstipulate.

Inflorescence a thyrse with cymose part-inflorescences usually sessile in the axils of often leaf-like bracts or reduced to single flowers so that it is spike-like; flowers bisexual, with at least the corolla zygomorphic and usually 2-lipped; sepals 5, rarely with 10 lobes, connate, more or less prominently veined, persistent; petals 5, fused into a tube and connate with the filaments, 2-lipped or otherwise zygomorphic with the number of lobes not necessarily equal to the petals; stamens 4, in pairs of unequal length and often only 2 fertile, with anthers 2- or rarely l-celled, often with the base of each cell diverging strongly so that the cells are attached end-on, or the connective between the 2 cells variously enlarged and/or shaped; ovary superior, usually 4-lobed fused to a gynobasic style at various levels, developed from 2 carpels and secondarily subdivided into 4 locules each with 1 erect anatropous ovule.

Fruit a schizocarp, i.e. a dry fruit which breaks into usually 4 mericarps each containing 1 seed, leaving behind a part of the ovary in the form of the central axis, sometimes not freely dehiscent.

Distribution:  Cosmopolitan about 180 genera and 3 500 species; particularly well represented in the Mediterranean region.

Biology: The inflorescence is here defined as that part of the branch where the nodes bear flowers whether branched or simple, or bear leaf-like bracts. These thyrses have few to many pairs of usually sessile cymose Part-inflorescences at the nodes and each pair is often referred to as a verticillaster in other publications. Sometimes the part-inflorescences are reduced to a single flower so that the whole inflorescence appears to be a spike or raceme as for instance in Teucrium racernosum except for small bracts (below) the apparently axillary flower. For instance in the case of Salvia reflexa the bracts are not present and the cymose derivation of the part-inflorescence can only be deduced from the position of the occasional development of more than 1 flower per leaf-axil.

Uses: The family is of considerable horticultural importance because of its ornamental plants such as species of Coleus, Moluccella, Phlornis, Plectranthus and Salvia, its aromatic herbs such as basil (Ocirnum basilicum), lavender (Lavandula dentara), mints (Mentha spp.), rosemary (Rosrnarinus officinalis) and thyme (Thymus vulgaris) and troublesome garden weeds such as Larnium amplexicaule and Stachys arvensis.

Taxonomic notes: As in the Boraginaceae the fruit is here termed a schizocarp because it breaks, only after some time in some cases, into 1-4 mericarps (conventionally called nutlets) and a central axis which is not shed. The sessile glands referred to in the text are usually oil glands which have a relative large multicellular head borne usually on a short stalk but occasionally they are embedded in the epidermis in particular of the leaves. These glands should not be confused with gland-tipped hairs.

Key to Genera:

1. Calyx 20-30 mm long, regularly connate, with 5 to l0 lobes	MOLUCCELLA 9.
1. Calyx to 15 mm long, if longer then 2-lipped or 2-lobed
2. Calyx scarcely lobed and with the posterior lobe with a broad appendage at the apex	LAVANDULA 4.
2. Calyx distinctly lobed to 2-lipped without an appendage to any lobe
3. Calyx actinomorphic with lobes about equal
4. Leaves in whorls of 3 or 4	WESTRINGIA 20.
4. Leaves opposite
5. Calyx with 10 setaceous lobes	MARRUBIUM 6.
5. Calyx with 5 or fewer lobes.
6. Corolla scarcely zygomorphic, 4-lobed
7. Mericarps with a concave outer surface and inner surfaces covered with sessile glands; fertile stamens 2; serrations of leaves pointed	LYCOPUS 5.
7. Mericarps with a convex outer surface, and inner surface without glands; fertile stamens usually 4; serrations of leaves usually blunt	MENTHA 8.
6. Corolla 1- or 2-lipped
8. Corolla 1-lipped
9. Corolla lip with 3 or 4 lobes, violet, blue to pink, rarely yellow	AJUGA 1.
9. Corolla lip with 5 often subequal lobes, white or cream	TEUCRIUM 18.
8. Corolla 2-lipped
10. Anthers hairy; mericarps narrowly oblong-obovoid, almost trigynous; corolla tube longer than both lips	LAMIUM 3.
10. Anthers glabrous; mericarps broadly obovoid, not keeled; corolla tube as long as or shorter than the anterior lip
11. Filaments glabrous; calyx with sessile glands	NEPETA 10.
11. Filaments hairy; calyx without sessile glands	STACHYS 17.
3. Calyx 2-lobed to 2-lipped or sometimes with 3 broad posterior and 2 narrow anterior lobes
12. Lips of calyx entire or almost so
13. Posterior lip of calyx without a protuberance	PROSTANTHERA 12.
13. Posterior lip of calyx with a prominent protuberance	SCUTELLARIA 16.
12. Lips or at least anterior lip of calyx distinctly lobed
14. Calyx hairy on the inside, sometimes only in parts
15. Calyx with dense long hairs and without sessile glands	STACHYS 17.
15. Calyx with sparse short hairs and with sessile glands
16. Leaves linear, entire	THYMUS 19.
16. Leaves ovate, serrate	CALAMINTHA 2.
14. Calyx glabrous on the inside
17. Inflorescence short and usually in the axils of the leaves; hairs branched	ROSMARINUS 14.
17. Inflorescence always terminal; hairs simple
18. Inflorescence compact, with internodes not visible between the part-inflorescences	PRUNELLA 13.
18. Inflorescence dissected with internodes visible at least between the lower part-inflorescences
19. Pedicel longer than or as long as the calyx; anterior lip of corolla not lobed	PLECTRANTHUS 11.
19. Pedicels rarely to two-thirds of the length of the calyx; anterior lip of corolla 3-lobed
20. Calyx and corolla without sessile glands; corolla indistinctly 2-lipped	MELISSA 7.
20. Calyx and corolla with more or less sessile glands; corolla distinctly 2-lipped	SALVIA 15.

Author: Prepared by H. R. Toelken; Prostanthera and Westringia by B. J. Conn