Ocimum L.

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Aromatic herbs or low shrubs; leaves opposite, usually serrate, the tissue finely dotted with pellucid glands.

Morphology Reproductive morphology Flowers

Flowers small, in 4–10-flowered whorls arranged in terminal racemes or panicles, the pedicels usually recurved

Morphology Reproductive morphology Flowers Calyx

Calyx 2-lipped, the upper lip broad, the edges wing-like and decurrent along the tube, the lower lip 4-lobed, the lobes ending in bristly teeth

Morphology Reproductive morphology Flowers Corolla

Corolla 2-lipped, the upper lip 4-lobed, the lower entire. Stamens 4, in 2 pairs, exserted

Morphology Reproductive morphology Fruits

Nutlets smooth or wrinkled, often mucilaginous when moistened.

Distribution

A genus of about 150 species, widely distributed in tropical and warm-temperate regions.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Herbs, subshrubs or small shrubs

Morphology Reproductive morphology Inflorescences

Inflorescences thyrse-like, lax or dense; bracts smaller and distinct from the leaves, persistent or deciduous, sometimes forming a coma at apex of the inflorescences; cymes 3-flowered (in Somali species), pedunculate absent or almost so; bracteoles absent

Morphology Reproductive morphology Flowers Calyx

Calyx 5-lobed or apparently 3-lobed, open or closed in fruit; upper lobe much larger than other lobes, decurrent along the tube; lateral lobes broad at the base, apically subulate, toothed or truncate to arcuate; lower lobes free or connate to an emarginate lower lip

Morphology Reproductive morphology Flowers Corolla

Corolla strongly 2-lipped; upper lip ± equally 4-lobed, almost flat; lower lip straight or deflexed, ± as long as or shorter than the upper lip, shallowly concave or almost flat

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens directed to the lower lip of the corolla, longer than the lower lip; posterior pair inserted in the proximal part of the corolla-tube, hairy, with knee-bend and/or appendage in basal part of filaments, or rarely straight and without appendage (O. spectabile)

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers with divergent or parallel thecae

Morphology Reproductive morphology Flowers Gynoecium Style

Style-branches equally long

Morphology Reproductive morphology Fruits

Nutlets obovoid, ellipsoid or subglobose, glabrous or hairy.

Distribution

Genus with about 67 species, widely distributed in the warm regions of the world.

Suddee, S., A. J. Paton, & Parnell, J. (2005). Taxonomic Revision of Tribe Ocimeae Dumort. (Lamiaceae) in Continental South East Asia III. Ociminae. Kew Bulletin, 60(1), 3-75. Retrieved from http://www.jstor.org/stable/4110885

Type

Type species: Becium bicolor Lindl. (= Ocimum grandiflorum Lam.). Lectotype species: Ocimum basilicum L. Becium Lindl.

Morphology General Habit

Erect annual or perennial herbs or undershrubs, usually aromatic. Stems quadrangular or round- quadrandgular, often woody at base and much branched

Morphology Stem

Stems quadrangular or round- quadrandgular, often woody at base and much branched

Morphology Leaves

Leaves petiolate, opposite, membranous to chartaceous, margin entire to serrate

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, simple or branched at base; verticils clearly interrupted; cymes sessile, unbranched, 3-flowered; bracts small or large, clawed or subsessile, sometimes forming an apical coma, caducous, sometimes leaving a prominent circular persistent gland at base

Morphology Reproductive morphology Flowers Calyx

Calyx ovoid or campanulate in flower and fruit, bilabiate, reflexed against the inflorescence axis in fruit; posterior lip broad, 1-lobed, orbicular or obovate, strongly reflexed and decurrent on tube in fruit; anterior lip 4-lobed, unequal, usually curved upwards and sometimes closing throat, equal or longer than posterior, teeth of lateral lobes deltoid or lanceolate, sometimes fringed, sinuate or with a row of many minute teeth, teeth of median lobes lanceolate or aristate; tube rarely constricted at throat, with 10 longitudinal veins; throat glabrous or with a ring of hairs

Morphology Reproductive morphology Flowers Corolla

Corolla subequal to or exserted from calyx tube; posterior lip erect, subequally 4-lobed; anterior lip longer, horizontal, flat or concave, entire; tube straight, dorsally gibbous at midpoint, dilated towards throat

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, didynamous, declinate, exserted, subequal or with the anterior ones slightly longer; posterior attached near the base of corolla tube, appendiculate with a glabrous or hairy transverse process or with a tuft of hairs near base; anterior usually attached near the corolla throat, glabrous and inappendiculate; filaments free; anthers synthecous, often confluent

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary glabrous

Morphology Reproductive morphology Flowers Gynoecium Style

Style declinate, bifid with branches usually subequal, subulate and flattened

Morphology Reproductive morphology Flowers Disc

Disc more or less equally 4- lobed

Morphology Reproductive morphology Fruits

Nutlets obovoid, oblong, ellipsoid or subglobose, smooth or finely warty, sometimes producing mucilage when wet.

Note

For further African generic and specific synonyms see Paton (1992, Paton et al. 1999). These works do not deal with Asiatic synonyms in great detail.

Lamiaceae (Labiatae), A.J. Paton, G. Bramley, O. Ryding, R.M. Polhill, Y.B. Harvey, M. Iwarsson, F. Willis, P.B. Phillipson, K. Balkwill, C.W. Lukhoba, D.F. Otieno, & R.M. Harley. Flora of Tropical East Africa. 2009

Morphology General Habit

Annual or perennial, herbs or shrubs, usually aromatic; indumentum of simple or dendroid hairs

Morphology Stem

Stems erect, usually branching above, often woody at base

Morphology Leaves

Leaves opposite or occasionally ternate, petiolate or rarely subsessile

Morphology Reproductive morphology Flowers

Flowers hermaphrodite, arranged in generally 6-flowered verticils, in a lax or dense inflorescence; bracts small or occasionally large and brightly coloured, sometimes forming a terminal coma, persistent or, if caducous, bract-scar often developing into an auxiliary nectary

Morphology Reproductive morphology Flowers Calyx

Calyx funnel-shaped to tubular, straight, curving upwards or rarely bent downwards, 2-lipped; posterior lip large, entire, rounded at tip, decurrent on tube, curving upwards; anterior lip 4-lobed, teeth of lateral lobes lanceolate or deltate, teeth of median lobes deltate to subulate at anthesis; in fruit posterior lip accrescent, curving up or rarely flat; anterior lip sometimes closing the calyx-throat; throat sometimes densely hairy

Morphology Reproductive morphology Flowers Corolla

Corolla whitish or pinkish, strongly 2-lipped; tube straight or curved towards base, usually dorsally gibbous at midpoint, often dilating towards throat; posterior lip subequally 4-lobed or with median exceeding lateral lobes, entire or fimbriate; anterior lip ± horizontal, flat or slightly concave

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, declinate, equal or unequal, exserted; posterior pair attached near base of corolla, rarely sterile, exserted, filaments usually pubescent at base, often appendiculate; anterior pair attached near corolla throat, glabrous; anthers dorsifixed, synthecous

Morphology Reproductive morphology Flowers Disc

Disk equally 4-lobed

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary glabrous or with minute hairs, deeply 4-lobed; style gynobasic, bifid, branches equal, subulate

Morphology Reproductive morphology Fruits

Nutlets black or brown, ovoid or spherical, with a small basal scar or not, smooth or minutely hairy, sometimes producing mucilage on wetting or not; embryo straight, exalbuminous.

Note

The most commonly cultivated in the Flora area are O. basilicum, O. africanum, O. gratissimum and O. kilimandscharicum. The genus has recently been broadened to include Becium, Erythrochlamys and Nautochilus. An infrageneric arrangement is elaborated by A. Paton, R.M. Harley & M.M. Harley in Y. Holm & R. Hiltunen (eds), Ocimum: Medicinal and Aromatic Plants – industrial profiles: 1–38 (1999), in Series Ed. Hardman, Harwood Academic, Amsterdam. The East African species belong to the following sections and subgenera – for more details of subsections and series see Paton et al., loc. cit. (1999).

Use

Ocimum basilicum L., or basil, is a well-known culinary herb.