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The genera of Leguminosae-Caesalpinioideae & Swartzieae

L. Watson and M.J. Dallwitz

Goniorrachis Taub.

Type species: G. marginata Taub.

Habit and leaf form. Shrubs; unarmed.

Phyllotaxy spiral. The leaves compound; pinnate; paripinnate. The leaflets few per leaf (2 pairs); basally markedly asymmetrical; with neither gland-dots nor domatia, with a strong, continuous marginal nerve (and the margins sinuous to crenate). Stipules absent or early caducous or very inconspicuous in mature leaves. Stipels absent.

Inflorescence and floral morphology. The inflorescences terminal; branched; of racemose units; fascicles (of few-flowered, flexuose spikes). The flowers distichous (?). Bracts absent at anthesis. Bracteoles present; small, not enclosing the flower buds; persistent beyond anthesis; suborbicular, not valvate; connate (forming a cup).

The flowers medium sized; hermaphrodite; obliquely zygomorphic, not pentamerous throughout; departing from pentamery in the calyx; white or green. Floral tube length relative to total hypanthium + calyx length about 0.25. Hypanthium present; shortly tubular (nearly as long as the sepals). The perianth comprising distinct calyx and corolla. Calyx 4; covering the rest of the flower in bud; polysepalous (the sepals ovate); members imbricate (with the abaxial one exterior). Corolla present; slightly irregular; 5; without greatly reduced members (the five obovate petals well developed and sub-equal); polypetalous. Petals all shortly clawed; imbricate; imbricate-ascending; white. The androecium comprising 10 members; members all free of one another; members markedly unequal (five being slightly longer); comprising only fertile stamens. Fertile stamens 10. Anthers attached well above the base of the connective. Ovary stipitate; eccentric, with the stipe adnate. Ovules numerous.

Fruit, seed and seedling. Seeds with a straight or slightly oblique radicle.

Transverse section of lamina. Druses common in 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 markedly sinuous in high-focus optical section; not conspicuously pitted; medium-thick. Stomata adaxially common and widespread. Abaxial: Abaxial stomata predominantly paracytic. Abaxial epidermis not papillate. Abaxial interveinal epidermal cell walls markedly sinuous in high-focus optical section; not conspicuously pitted in optical section; staining normally with safranin; medium-thick.

Wood anatomy. Wood storied.

Pollen ultrastructure. Tectum reticulate; finely to moderately regularly reticulate. Length of colpi greater than one half pole to pole distance.

Species number and distribution. 1 species (G. marginata). Southeast Brazil.

Tribe. Detarieae.

Miscellaneous. Illustrations: • G. marginata, e.m. scanned pollen (Graham & Barker, 1981).

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: 22nd March 2017.’.