The genera of Leguminosae-Caesalpinioideae & Swartzieae
Type species: L. rhodostegia Hance.
Habit and leaf form. Trees, or shrubs; unarmed.
Phyllotaxy distichous. The leaves compound; pinnate; paripinnate. The leaflets opposite or sub-opposite; petiolulate; with markedly twisted petiolules; symmetrical or nearly so; pinnately veined, with a predominant midrib; with a strong, continuous marginal nerve. Stipules intrapetiolar connate. Stipels present.
Inflorescence and floral morphology. The inflorescences axillary and terminal; branched; of racemose units; panicles. The flowers not distichous. Bracts large, coloured, persistent beyond anthesis. Bracteoles present (at the base of the calyx); petaloid, relatively large and enclosing the flower buds; persistent beyond anthesis; not valvate; free.
The flowers hermaphrodite; not pentamerous throughout; departing from pentamery in the calyx and in the corolla. Floral tube length relative to total hypanthium + calyx length about 0.5. Hypanthium present; tubular (the tube fleshy). The perianth comprising distinct calyx and corolla. Calyx 4; covering the rest of the flower in bud; polysepalous; more or less regular; members imbricate (reflexing). Corolla present; very irregular (the three petals all similar); slightly exceeded by the calyx 3; without greatly reduced members; polypetalous. Petals all long clawed. The androecium comprising 6 members; declinate; with united members (the filaments basally connate into a short ring); members markedly unequal; including staminodia. The staminodia 2; minute, with abortive anthers. Fertile stamens 4. Anthers attached well above the base of the connective. Ovary exserted, stipitate; eccentric, with the stipe adnate. Stigma not dilated (the style filiform, circinate in bud). Ovules numerous (about 12).
Fruit, seed and seedling. Fruit a two-valved pod; valves twisting and enrolling during dehiscence; large, flat, apiculate, not becoming woody. Seeds non-endospermic; with a straight or slightly oblique radicle. Cotyledons of Type 4; with a vascular system in one plane.
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 common (the veins transcurrent). 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 common. 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-thin. Stomata adaxially very rare. 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; thin.
Pollen ultrastructure. Tectum striate; reticulate striate. Length of colpi greater than one half pole to pole distance.
Species number and distribution. 1 species (L. brevicalyx, L. rhodostegia). South China, Vietnam.
Tribe. Detarieae; Amherstieae clade of Bruneau et al. (2008).
Miscellaneous. Illustrations: • L. rhodostegia: Hook. Ic. Pl. 12 (1876). • L. rhodostegia, 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. delta-intkey.com/caes’.