The families of flowering plants.
AlternativelyLabiaceae Dulac, Labiataceae Boerl., Lamiaceae Lindl. (nom. altern.)
IncludingMenthaceae Burnett, Nepetaceae Horan., Salazariaceae F. Barkley, Scutellariaceae CaruelExcluding Tetrachondraceae
Habit and leaf form. Herbs (usually), or shrubs (sometimes ericoid), or trees (rarely), or lianas (rarely); characteristically bearing essential oils (the crushed foliage aromatic or foetid, with taxonomic predictability). Plants succulent (rarely, e.g. some Coleus spp.), or non-succulent (mostly). The herbs annual to perennial; with neither basal nor terminal aggregations of leaves. Self supporting (usually), or climbing (occasionally). Helophytic, or mesophytic, or xerophytic. Leaves opposite (decussate on the usually square stem), or whorled; when whorled, 3–10 per whorl (e.g. Dysophylla); flat, or folded, or rolled, or terete; ‘herbaceous’ (mostly), or leathery, or fleshy; petiolate to sessile; aromatic, or foetid, or without marked odour (very rarely); simple, or compound; epulvinate; when compound, pinnate. Lamina dissected, or entire; when dissected, pinnatifid, or palmatifid; one-veined, or pinnately veined, or palmately veined; cross-venulate; cordate to cuneate at the base, or rounded at the base. Leaves exstipulate. Lamina margins entire, or crenate, or serrate. Leaves without a persistent basal meristem. Domatia occurring in the family (Cuminia); manifested as pockets.
Leaf anatomy. Hydathodes present (ocasionally), or absent. Abaxial epidermis not papillose. Stomata predominantly diacytic, or anomocytic, or anisocytic, or anomocytic and anisocytic. Hairs usually present (usually with conspicuous glandular hairs); usually eglandular and glandular; unicellular, or multicellular. Unicellular hairs branched, or unbranched. Multicellular hairs uniseriate, or multiseriate; branched, or unbranched. Complex hairs present, or absent; stellate. Urticating hairs absent.
Adaxial hypodermis absent. Lamina dorsiventral, or isobilateral, or centric. Midrib conspicuous. Main veins embedded. Minor leaf veins without phloem transfer cells (8 genera).
Stem anatomy. Stems with solid internodes, or with spongy internodes, or with hollow internodes. Young stems usually tetragonal. Secretory cavities absent. Cork cambium present; initially deep-seated, or superficial. Nodes unilacunar (with 1 or 2 traces). Primary vascular tissue comprising a ring of bundles (four, one in each corner of the stem); centrifugal. Cortical bundles absent. Medullary bundles absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem without fibre tracheids; with libriform fibres; with vessels. Vessel end-walls simple. Vessels with vestured pits (rarely), or without vestured pits. Primary medullary rays wide, or mixed wide and narrow, or narrow. Wood ring porous to diffuse porous; parenchyma paratracheal (rather sparse to very sparse). Sieve-tube plastids S-type. Pith with crystalline inclusions, or without crystalline inclusions.
Reproductive type, pollination. Plants hermaphrodite, or dioecious, or gynodioecious (fairly commonly), or polygamomonoecious (rarely). Pollination entomophilous, or ornithophilous; usually via hymenoptera, or via lepidoptera, or via diptera.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; in verticils (usually, these usually formed from axillary pairs of dichasial or circinate cymes), or in heads, or in spikes, or in cymes, or in panicles. The ultimate inflorescence unit cymose. Inflorescences terminal, or axillary. Flowers minute to medium-sized; somewhat irregular to very irregular; zygomorphic; resupinate (by torsion of pedicel or (e.g. in Teucrium, Ajuga) the corolla tube), or not resupinate. The floral irregularity involving the perianth and involving the androecium (though sometimes not the calyx). Flowers cyclic; tetracyclic. Floral receptacle developing a gynophore, or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk often present, or absent.
Perianth with distinct calyx and corolla; 4–10; 2 whorled; isomerous, or anisomerous (or only dubiously interpretable). Calyx 2, or 3, or 4, or 5 (basically 5, but often with the bilabiate condition superimposed, and 2-lobed in e.g. Prostanthera, 3-lobed in Melittis, 4-lobed in e.g. Preslia); 1 whorled; variously gamosepalous; entire (occasionally), or blunt-lobed, or toothed. Calyx lobes markedly shorter than the tube to markedly longer than the tube. Calyx campanulate, or funnel-shaped, or tubular; unequal but not bilabiate (one-lipped), or bilabiate, or regular; persistent; imbricate, or open in bud (commonly); (when K 5) with the median member posterior. Corolla more or less disguisedly 5 (usually with no clear indication of individual petals — commonly with five lobes, but usually with the bilabiate condition superimposed, and the five lobes variously secondarily lobed, reduced or suppressed), or 4 (occasionally, ostensibly, e.g. Mentha); 1 whorled; gamopetalous; imbricate; bilabiate (usually, the lower lip typically three-lobed, the upper commonly bilobed or emarginate but sometimes entire or three or four lobed), or unequal but not bilabiate (e.g. Teucrium, where the upper lip is suppressed), or regular (rarely, almost, as in Mentha); plain, or with contrasting markings.
Androecium 2, or 4(–5) (usually). Androecial members adnate; all equal, or markedly unequal; usually free of one another, or coherent (in Coleus); in Coleus 1 adelphous; 1 whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 1 (posterior), or 2 (the posterior pair, or the anterior pair); in the same series as the fertile stamens; representing the posterior median member, or the posterior-lateral pair, or the anterior-lateral pair. Fertile stamens representing the posterior-lateral pair, or the anterior-lateral pair, or the posterior-lateral pair and the anterior-lateral pair (commonly). Stamens 2, or 4; inserted near the base of the corolla tube (rarely, e.g. Teucrium), or midway down the corolla tube, or in the throat of the corolla tube (and sometimes the pairs attached at different levels); didynamous (usually, with the anterior pair longer), or not didynamous, not tetradynamous; reduced in number relative to the adjacent perianth (at least theoretically); oppositisepalous. Anthers connivent (in pairs, commonly), or separate from one another; dorsifixed; versatile, or non-versatile; dehiscing via longitudinal slits; introrse; unilocular to bilocular; tetrasporangiate; appendaged, or unappendaged. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or decussate. Anther wall initially with one middle layer; of the ‘dicot’ type. Tapetum glandular. Pollen monosiphonous; shed as single grains. Pollen grains aperturate; 3 aperturate, or 4 aperturate, or 6 aperturate; colpate, or colporate; 2-celled (in 52 genera), or 3-celled (in 70 genera), or 2-celled and 3-celled (with both states in 3 genera).
Gynoecium 2 carpelled (but the carpels deeply lobed to mimic G4). Carpels reduced in number relative to the perianth. The pistil 4 celled. Gynoeciumsyncarpous; synstylovarious to eu-syncarpous; superior. Ovary2 locular (originally, but usually becoming ostensibly four by intrusions of the ovary wall constituting ‘false septa’). Locules secondarily divided by ‘false septa’. Gynoecium median. Styles 1; when ‘apical’, from a depression at the top of the ovary (then the ovary deeply lobed); ‘gynobasic’ (usually), or apical. Stigmas 2, or 1 (by reduction); 2 lobed; dry type; papillate; Group II type. Placentation basal. Ovules 2 per locule, or 1 per locule (two per original loculus, but one per locellus);ascending; apotropous; with ventral raphe (and the micropyle directed downwards); non-arillate; anatropous, or hemianatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; proliferating (rarely, e.g. Physostegia), or not proliferating; ephemeral, or persistent. Synergids commonly hooked. Endosperm formation cellular. Endosperm haustoria present; usually chalazal and micropylar (the latter aggressive). Embryogeny nearly always onagrad (rarely asterad).
Fruit usually non-fleshy, or fleshy (rarely); more or less a schizocarp (except perhaps in Eichlerago (= Prostanthera), where it is said to be hard, indehiscent and non-schizocarpic). Mericarps (2–)4; comprising nutlets (typically of four nutlets, distinct or cohering pairwise, enclosed in the persistent calyx), or comprising drupelets (rarely, e.g. Prasieae). Seeds endospermic to non-endospermic (the scant, fleshy endosperm often absorbed by the developing embryo). Embryo well differentiated (with a downward-pointing radicle, by contrast with Boraginaceae). Cotyledons 2; flat. Embryo achlorophyllous (16/23); straight.
Seedling.Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Cyanogenic (rarely), or not cyanogenic. Alkaloids present (commonly), or absent. Iridoids detected (commonly); ‘Route II’ type (normal and decarb.). Verbascosides detected (in 6 genera, absent from Lamium album). Cornoside detected (Teucrium). Proanthocyanidins absent. Flavonols mostly absent. Ellagic acid absent (15 species, 14 genera). Ursolic acid present. Saponins/sapogenins absent. Aluminium accumulation not found. Sugars transported as sugar alcohols + oligosaccharides + sucrose (in Rosmarinus, Salvia). C3 and CAM. C3 physiology recorded directly in Coleus, Hedeoma, Hyptis, Leonurus,Leucas, Lycopus, Marrubium, Mentha, Monarda,Perilla, Prunella, Salvia, Stachys, Teucrium,Thymus. CAM recorded directly in Plectranthus. Anatomy non-C4 type (Hedeoma, Lycopus, Marrubium, Mentha, Perovskia,Phlomis, Salvia, Stachys, Teucrium, Ziziphora).
Geography, cytology. Frigid zone to tropical. Cosmopolitan. X = 5–11(+).
Taxonomy.Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Lamiales. Cronquist’s Subclass Asteridae; Lamiales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Lamiales.
Species about 3500. Genera about 210; Acanthomintha, Achyrospermum, Acinos,Acrocephalus, Acrotome, Acrymia, Aeollanthus, Agastache,Ajuga, Ajugoides, Alajja, Alvesia, Amethystea,Anisochilus, Anisomeles, Antonina, Asterohyptis, Ballota,Basilicum, Becium, Benguellia, Blephilia, Bostrychanthera,Bovonia, Brazoria, Bystropogon, Calamintha, Capitanopsis,Capitanya, Catoferia, Cedronella, Ceratanthus, Chamaesphacos,Chaunostoma, Chelonopsis, Cleonia, Clinopodium, Colebrookia,Coleus(=Plectranthus),, Collinsonia, Colquhounia, Comanthosphace,Conradina, Craniotome, Cuminia, Cunila, Cyclotrichium,Cymaria, Dauphinea, Dicerandra, Dorystaechas, Dracocephalum,Drepanocaryum, Eichlerago, Elsholtzia, Endostemon, Englerastrum,Eremostachys, Eriope, Eriiophyton, Eriopidion, Eriothymus,Erythrochlamys, Eurysolen, Fuerstia, Galeopsis, Geniosporum,Glechoma, Glechon, Gomphostemma, Gontscharovia, Hanceola,Haplostachys, Haumaniastrum, Hedeoma, Hemiandra, Hemigenia,Hemizygia, Hesperozygis, Heterolamium, Hoehnea, Holocheila,Holostylon, Horminium, Hoslundia, Hymenocrater, Hypenia,Hypogomphia, Hyptidendron, Hyptis, Hyssopus, Isodictyophorus,Isodon, Isoleucas, Keiskea, Kinostemon, Kudrjaschevia,Kurzamra, Lagochilus, Lagopsis, Lallemantia, Lamiophlomis,Lamium, Lavandula, Leocus, Leonotis, Leonurus,Lepechinia, Leucas, Leucosceptrum, Limniboza, Lophanthus,Loxocalyx, Lycopus, Macbridea, Marmoritis, Marrubium,Marsypianthes, Meehania, Melissa, Melittis, Mentha,Meriandra, Mesona, Metastachydium, Microcorys, Micromeria,Microtoena, Minthostachys, Moluccella, Monarda, Monardella,Mosla, Neoeplingia, Neohyptis, Nepeta, Neustruevia,Nosema, Notochaete, Ocimum, Octomeron, Ombrocharis,Origanum, Orthosiphon, Otostegia, Panzerina, Paraeremostachys,Paralamium, Paraphlomis, Peltodon, Pentapleura, Perilla,Periloma (Scutellaria), Perovskia, Perrierastrum, Phlomis,Phlomoides, Phyllostegia, Physostegia, Piloblephis,Pitardia, Platostoma, Plectranthus, Pogogyne, Pogostemon,Poliomintha, Prasium, Prostanthera, Prunella, Pseuderemostachys,Puntia, Pycnanthemum, Pycnostachys, Renschia, Rhabdocaulon,Raphidion, Rhododon, Rosmarinus, Rostrinucula, Roylea,Rubiteucris, Sabaudia, Saccocalyx, Salvia, Satureja,Schizonepeta, Scutellaria, Sideritis, Siphocranion,Skapanthus, Solenostemon, Stachyopsis, Stachys, Stenogyne,Sulaimania, Suzukia, Symphostemon, Synandra, Syncolostemon,Tetradenia, Teucrium, Thorncroftia, Thuspeinanta, Thymbra,Thymus, Tinnea, Trichostema, Wenchengia, Westringia,Wiedemannia, Wrixonia, Zataria, Zhumeria, Ziziphora.
General remarks. Junell (1934), Erdtman (1945), Wunderlich (1967) and El-Gazzar and Watson (1970), all expressed dissatisfaction with traditional classifications of Labiatae, and with the circumscription of Labiatae relative to that of Verbenaceae sensu lato, based on very extensive comparative anatomical, palynological, phytochemical, morphological and host/parasite surveys. Their ideas, extended by morphological-cladistic and molecular studies, are now in process of being implemented formally in the shape of a fairly radically revised classification (cf. Cantino et al., 1992). The latter, however, is not yet available complete with the detailed, revised family descriptions necessary for incorporation in the present package.
Economic uses, etc. The source, par excellence, of aromatic and antibiotic essential oils for the pharmaceutical and cosmetics industries (species of Salvia, Lavandula,Rosmarinus, Mentha, Marrubium, Pogostemon etc.), and of aromatic/flavoursome pot herbs (Salvia, Origanum, Thymus,Ocimum, Satureia etc.). Many are cultivated as ornamentals (Salvia,Ajuga, Physostegia, Monarda, Scutellaria, Nepeta,Teucrium, Stachys, Phlomis etc.).