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The families of flowering plants

L. Watson and M.J. Dallwitz

Cytinaceae Brongn.

~ Rafflesiaceae sensu lato.

Habit and leaf form. Very peculiar endoparasitic herbs. Plants of very peculiar vegetative form; the vegetative parts filamentous, or fungoid. Leaves much reduced, or absent (depending on interpretation). Plants rootless; parasitic (on an assorted range of hosts, including Burseraceae, Cistaceae, Compositae, Hamamelidaceae, Cochlospermaceae, Moraceae - infecting the roots, then permeating the host tissues, with only the flowering stems becoming exserted at the bases of flowering stems or beneath the flowers); endoparasitic; not green. Leaves (if the scales beneath the flowers are so interpreted,) alternate, or opposite, or whorled (usually); membranous (scales).

Leaf anatomy. Stomata absent.

Axial (stem, wood) anatomy. Secondary thickening absent (the vascular system vestigial or absent). The axial xylem when present, without vessels.

Reproductive type, pollination. Plants monoecious, or dioecious (?). Pollination entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. Inflorescences spicate. Flowers small to medium-sized; malodorous (often), or odourless; regular; cyclic. Floral receptacle developing an androphore, or developing a gynophore, or with neither androphore nor gynophore (depending on interpretation of the floral columns).

Perianth sepaline, or petaline, or of ‘tepals’ (depending on interpretation); 4 (always?); joined (forming a tube), or free (?); 1 whorled (preceded by numerous scales); somewhat fleshy, or non-fleshy (?).

Androecium of male flowers 15–100 (to ‘many’). Androecial members free of the perianth; united with the gynoecium, or free of the gynoecium (depending on morphological interpretation of the central column); free of one another (the elongate, sessile anthers arranged in a ring around the swollen head of the central column); 1 whorled. Androecium exclusively of fertile stamens. Stamens 15–100 (to ‘many’); with sessile anthers. Anthers dehiscing via longitudinal slits; extrorse; unilocular, or bilocular (?); tetrasporangiate. Microsporogenesis simultaneous. Pollen shed as single grains. Pollen grains aperturate; 2–3(–4) aperturate; colpate, or porate.

Gynoecium (in female flowers) 4–8 carpelled (? - several). The pistil 4–8 celled (?). Gynoecium syncarpous; synstylovarious, or eu-syncarpous (the stout, columnar style clavate); inferior. Ovary 4–8 locular (by deep intrusion of the placentas). Gynoecium stylate. Styles 1; apical. Stigmas truncate. Placentation parietal (or with the very minute ovules covering the inner surfaces of the partitions). Ovules 25–100 per locule (‘very numerous’, and very minute); non-arillate; orthotropous; bitegmic; tenuinucellate. Outer integument not contributing to the micropyle.

Fruit fleshy; indehiscent; a berry; many. Seeds non-endospermic; minute. Embryo rudimentary at the time of seed release.

Physiology, phytochemistry. Sieve-tube plastids when present, lacking both protein and starch.

Geography, cytology. Temperate (warm), sub-tropical to tropical. Mediterranean, Africa and Madagascar.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Santaliflorae; Santalales (cf. Hydnoraceae). Cronquist’s Subclass Rosidae; Rafflesiales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Malvales.

Species about 10. Genera 2; Bdallophytum, Cytinus.

General remarks. Differing from Rafflesiaceae in six characters involving inflorescence, perianth, pollen, ovule and seed.

Illustrations. • Bdallophytum andrieuxii: Eichler, Bot. Zeitung 30 (1872). • Le Maout and Decaisne: Cytinus. • Le Maout and Decaisne: Cytinus, with Rafflesia (Rafflesiaceae). • Cytinus sanguineus, as C. dioicus: Hook. Ic. Pl. 4 (1841). • Cytinus hypocistis: Thomé, Flora von Deutschland Osterreich und der Schweiz 3 (1885).

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Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 15th April 2018.’.