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The families of flowering plants

L. Watson and M.J. Dallwitz

Turneraceae DC.

~ Passifloraceae s. l.

Habit and leaf form. Trees (rarely), or shrubs, or herbs. Leaves alternate; spiral; petiolate; simple. Lamina dissected, or entire; when dissected, pinnatifid; pinnately veined; cross-venulate. Leaves stipulate (Erblichia), or exstipulate (usually, but often with a pair of glands or extrafloral nectaries at the base of the blade). Stipules and/or prophylls and leaf primordia with colleters. Lamina margins serrate, or dentate (the teeth sometimes glandular).

Leaf anatomy. The leaf lamina dorsiventral (usually), or bifacial (then isobilateral, not uncommonly). Mucilaginous epidermis present, or absent. Stomata variously mainly confined to one surface, or on both surfaces; paracytic (usually, mostly), or anomocytic and anisocytic. Hairs present (with numerous kinds represented in the family); eglandular and glandular; unicellular and multicellular. Complex hairs present, or absent; when present, sometimes stellate. The mesophyll with sclerenchymatous idioblasts (e.g., in Turnera), or without sclerenchymatous idioblasts; containing crystals. The crystals druses. Minor leaf veins without phloem transfer cells (Turnera).

Axial (stem, wood) anatomy. Cork cambium present; initially superficial (at least in Turnera). Primary vascular tissues in a cylinder, without separate bundles; collateral. Cortical bundles representing foliar traces present, or absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring.

The wood diffuse porous. The vessels small to medium; in short to long multiples. The vessel end-walls simple, or scalariform and simple. The vessels without vestured pits; without spiral thickening. The axial xylem with fibre tracheids, or without fibre tracheids; with libriform fibres, or without libriform fibres; without septate fibres. The fibres without spiral thickening. The parenchyma diffuse apotracheal (or i fine reticulate lines); wood not storied.

Reproductive type, pollination. Plants hermaphrodite; heterostylous. Pollination self-pollinated or entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary; when aggregated, in racemes. Inflorescences terminal, or axillary, or epiphyllous (in 10 species of Turnera). Flowers often (bi-) bracteolate; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present (this short to tubular).

Perianth with distinct calyx and corolla (and sometimes with a membranous corona, inserted below the throat of the calyx or at the base of the sepals); 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous; toothed; regular (usually with a hemispherical swelling inside); not persistent; imbricate. Corolla 5; 1 whorled; polypetalous; contorted; regular; yellow, or red; deciduous. Petals clawed.

Androecium 5. Androecial members free of the perianth (inserted low in the hypanthium); free of one another; 1 whorled. Androecium exclusively of fertile stamens (but the hypanthium often provided with five extrastaminal glands or protuberances, or (Piriquetia, Erblichia) with a narrow, fringed corona). Stamens 5; isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers dehiscing via longitudinal slits; introrse. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. Anther wall initially with more than one middle layer (with 2). Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 3 aperturate; colporate (or colporoidate); 2-celled.

Gynoecium 3 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious; superior to partly inferior. Ovary 1 locular; sessile. Gynoecium stylate. Styles 3 (opposite the placentas); free. Stigmas 3 (fringed); commissural (assuming ’opposite the placentas‘ means aligned with them); dry type; non-papillate; Group II type (a). Placentation parietal. Ovules in the single cavity (3–)25–100 (to ‘many’); funicled; ascending; arillate (with an ostensibly funicular aril); anatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Endosperm formation nuclear. Embryogeny onagrad.

Fruit non-fleshy; dehiscent; a capsule. Capsules valvular (each of the three valves with a median placenta). Seeds copiously endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2; planoconvex. Embryo straight.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. Cyanogenic (often), or not cyanogenic. Cynogenic constituents of the gynocardin group (?). Alkaloids present, or absent. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent.

Geography, cytology. Mainly sub-tropical to tropical (a few warm temperate). Tropical and South Africa, Madagascar, Mascarenes, Central and tropical South America, West Indies. X = 7, 10.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Violiflorae; Violales. Cronquist’s Subclass Dilleniidae; Violales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Malpighiales (as a synonym of Passifloraceae).

Species 120. Genera 10; Adenoa, Erblichia, Hyalocalyx, Loewia, Mathurina, Piriqueta, Stapfiella, Streptopetalum, Tricliceras (Wormskioldia), Turnera (with half the species).

General remarks. Differing from Passifloraceae (q.v.) in the sometimes pinnatifid leaves, stipules with colleters, racemose inflorescences, ephemeral calyx, contorted corolla, absence of staminodes, sessile ovary and commissural stigmas ....

Illustrations. • Turnera dichotoma: Hook. Ic. Pl. 5–6 (1842–3). • Erblichea odorata: Seeman, Fitch & Hooker, Herald voyage (1852). • Le Maout and Decaisne: Turnera. • Wormskioldia lobata: Thonner. • Turnera ulmifolia var. angustifolia: Bot. Mag. 281, 1794. • Loewia tanaensis: Hook. Ic. Pl. 31 (1915).

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, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 5th March 2018.’.