| # The genera of Leguminosae-Caesalpinioideae and Swartzieae |

L. Watson and M.J. Dallwitz

### Tamarindus L.

Cavaraea Spreg.

Type species: T. indica L.

Habit and leaf form. Trees; unarmed.

Phyllotaxy spiral. The leaves compound; pinnate; paripinnate. The leaflets many per leaf; opposite or sub-opposite; sessile to sub-sessile; symmetrical or nearly so; pinnately veined, with a predominant ‘midrib’. Stipules absent or early caducous or very inconspicuous in mature leaves (deciduous); membranous. Stipels absent.

Inflorescence and floral morphology. The inflorescences terminal; unbranched; simple racemes. The flowers not distichous. Bracts absent at anthesis. Bracteoles present; relatively large and enclosing the flower buds; absent at anthesis; valvate.

The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx, or in the calyx and in the androecium; coloured. Floral tube length relative to total hypanthium + calyx length 0.25. Hypanthium present; asymmetrically tubular. The perianth comprising distinct calyx and corolla. Calyx 4; covering the rest of the flower in bud; not Swartzieae type; polysepalous; markedly irregular; members imbricate. Corolla present; very irregular (comprising 3 large adaxial petals, the uppermost of which is inside and narrower, and two tiny vestiges); 3–5; including greatly reduced members; polypetalous. Petals almost clawed to sessile (the large ones being subsessile); imbricate; imbricate-ascending; yellow and red (yellow with a red tinge). The androecium comprising (dubiously) 4–6 members; declinate; with united members (the abaxial three stamens being connate into a sheath that is open above); members markedly unequal; including staminodia. The staminodia few; minute, at the apex of the sheath. Fertile stamens with short filaments, 3. Anthers attached well above the base of the connective; dehiscing longitudinally. Ovary stipitate; eccentric, with the stipe adnate. Stigma minutely dilated (capitellate on the slender style). Ovules numerous.

Fruit, seed and seedling. Fruit indehiscent (with a dry shell and pulpy endocarp); oblong-linear, somewhat compressed, curved; internally septate; not becoming woody. The mature valves without prominent venation. Seeds non-endospermic; not arillate; with a straight or slightly oblique radicle; amyloid-positive. Cotyledons not flat; of Type 4; with a vascular system in one plane; epigeal.

Transverse section of lamina. Leaves with conspicuous phloem transfer cells in the minor veins. Druses absent from the mesophyll. Mesophyll secretory cavities absent. Adaxial hypodermis absent. Leaf girders absent. Laminae dorsiventral. Mesophyll without unaligned fibres or sclereids. Minor veins mainly with abundant accompanying fibres.

Leaf lamina epidermes. Epidermal crystals not seen either adaxially or abaxially. Simple unbranched hairs not seen. No compound or branched eglandular hairs seen. Capitate glands not seen. Expanded and embedded hair-feet absent. Adaxial: Adaxial interveinal epidermal cell walls straight in optical section; not conspicuously pitted; thin. Stomata adaxially common and widespread. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls straight, or gently undulating; conspicuously pitted in optical section; staining normally with safranin; thin.

Wood anatomy. Wood without septate fibres; storied, or not storied. Intervascular pits medium to large.

Pollen ultrastructure. Tectum striate; interwoven striate. Length of colpi greater than one half pole to pole distance.

Cytology. Basic chromosome number, x = 12. 2n = 24.

Species number and distribution. 1 species (T. indica). Tropical Africa.

Tribe. Detarieae (Amherstieae of Cowan and Polhill 1981); Amherstieae clade of Bruneau et al. (2008).

Comments. Widely cultivated.

Miscellaneous. Illustrations: • Tamarindus indica: Baillon, Histoire des Plantes 2 (1870). • Tamarindus indica: Nat. Pflanzenfam. III (1894).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classification. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1993 onwards. The genera of Leguminosae-Caesalpinioideae and Swartzieae: descriptions, illustrations, identification, and information retrieval. In English and French. Version: 4th August 2019. delta-intkey.com’.

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