Family Cyclanthaceae

Cyclanthaceae Dum.

Habit and leaf form. Shrubs, or lianas, or herbs; laticiferous, or non-laticiferous and without coloured juice. ‘Normal’ plants. Perennial. Self supporting, or epiphytic (rarely), or climbing; when climbing, root climbers (with short, climbing roots, sometimes also with long, unbranched rope roots). Stem growth not conspicuously sympodial. Leaves alternate; spiral (usually), or distichous; ‘herbaceous’, or leathery; petiolate; sheathing; simple, or compound; when compound palmate, or bifoliolate (Cyclanthus). Lamina when simple dissected (usually), or entire; when dissected, palmatifid (or bifid, in Cyclanthus); one-veined, or palmately veined (with one to three costae, the central lacking in Cyclanthus). Leaves becoming compound from primordial lobes.

General anatomy. Plants without silica bodies. Accumulated starch exclusively ‘pteridophyte type’ (Cyclanthoideae), or other than exclusively ‘pteridophyte type’ (Carludovicioideae).

Leaf anatomy. Stomata present; tetracytic.

Lamina with secretory cavities, or without secretory cavities (Cyclanthus). Secretory cavities containing mucilage (Carludovicoideae). The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides, or druses, or solitary-prismatic (including styloids). Vessels present, or absent (then with ‘vessel tracheids’); end-walls scalariform.

Stem anatomy. Secretory cavities present (usually), or absent (Cyclanthus, which has latex canals confined to the infloresence); when present, with mucilage. Cork cambium present (usually), or absent (Cyclanthus). Secondary thickening absent. Xylem without vessels (Wagner 1977). Sieve-tube plastids P-type; type II.

Root anatomy. Root xylem with vessels, or without vessels (then with ‘vessel tracheids’); vessel end-walls scalariform.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Plants monoecious. Female flowers with staminodes (with four conspicuous staminodia opposite the tepals, these subulate, vermiform or filiform, (1-)3–5(-10) cm long, white to red or yellow, with or without rudimentary anthers). Gynoecium of male flowers absent. Floral nectaries absent (nectaries absent). Pollination entomophilous; via beetles.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. Inflorescences terminal, or axillary; pedunculate, unbranched, long-cylindrical to subspherical spadices, with rather few to very numerous flowers; conspicuously spatheate (each spadix subtended by 2–4(-8) spathes, which vary in size, shape and colour — green, white, red or yellow). Flowers small (in most genera arranged in a chess-board mosaic of solitary females each surrounded by four males, the groups in a shallow spiral along the spadix; or in Cyclanthus, the male and female flowers in alternating cycles and fused laterally so as to be indistinguishable individually).

Perianth of ‘tepals’, or vestigial, or absent; 4; free, or joined (symmetric or asymmetric, usually a more or less lobed cupule when present in male flowers, free or basally connate in females); 1 whorled (usually), or 2 whorled (seemingly, in Evodianthus); sepaloid; fleshy (often, in female flowers), or non-fleshy; persistent; accrescent (often, in female flowers).

Androecium 4 (in female flowers), or 10–20(–150) (in male flowers of most genera, but in Cyclanthus the male flowers are so reduced as to be represented by cycles with numerous stamens in four rows). Androecial members free of the perianth; free of one another. Stamens 10–20(–150) (when individual flowers distinguishable); triplostemonous to polystemonous; often with basally bulbous filaments. Anthers basifixed; non-versatile; tetrasporangiate; appendaged, or unappendaged. The anther appendages when present, apical (in the form of a glandule). Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis successive. The initial microspore tetrads isobilateral, or decussate. Pollen grains aperturate; 1 aperturate (usually), or 2 aperturate; sulcate (or sulcoidate, mostly), or ulcerate (or ulceroidate, and Carludovicia having a proximal pore and a distal groove), or foraminate (biforaminate, Thoracocarpus); 2-celled.

Gynoecium 4 carpelled. Carpels isomerous with the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious to synstylovarious; partly inferior, or inferior. Ovary 1 locular (or in Cyclanthus, the female flowers reduced and fused into pistillate cycles, to the extent that the ovaries form a continuous cavity). Epigynous disk absent. Gynoecium non-stylate, or stylate. Styles 1, or 4; free to partially joined. Stigmas 4; laterally compressed, or flat, broad and fleshy; wet type; papillate; Group III type. Placentation parietal (with four placentas, or numerous parietal ovules in the continous cavity of Cyclanthus), or apical (rarely). Ovules in the single cavity 50–150 (‘many’); anatropous; tenuinucellate, or crassinucellate to pseudocrassinucellate (mostly). Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed, or not formed (? — contrast Davis 1966, pp. 21, 102); if formed, 3; not proliferating; ephemeral, or persistent. Synergids pear-shaped. Endosperm formation helobial.

Fruit fleshy; indehiscent; a berry (these usually more or less cohering within the spadix, sometimes coming free). Gynoecia of adjoining flowers usually combining to form a multiple fruit. The multiple fruits usually coalescing (to form a fleshy syncarp, the spadix twisting and becoming screwlike in Cyclanthus). Seeds copiously endospermic. Endosperm oily, or not oily (?). Seeds winged (with a long terminal appendage, in Stelestylis), or wingless. Seeds with starch (Cyclanthoideae), or without starch (Carludovicioideae). Embryo well differentiated (small to medium sized). Cotyledons 1. Embryo straight (usually, linear-cylindric), or curved (rarely). Testa without phytomelan.

Seedling. Hypocotyl internode absent. Seedling collar not conspicuous. Cotyledon hyperphyll compact; non-assimilatory. Coleoptile absent (but with pronounced cotyledon sheath lobes). First leaf dorsiventral. Primary root ephemeral.

Physiology, biochemistry. Not cyanogenic. Alkaloids present (one species). Proanthocyanidins absent. Flavonols absent. Ellagic acid absent.

Geography, cytology. Neotropical. Sub-tropical to tropical. Central and tropical South America, West Indies.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Cyclanthiflorae; Cyclanthales. APG 3 core angiosperms; Superorder Lilianae; non-commelinid Monocot; Order Pandanales.

Species 180. Genera 12; Asplundia, Carludovica, Chorigyne, Cyclanthus, Dianthoveus, Dicranopygium, Evodianthus, Ludovia, Schultesiophytum, Sphaeradenia, Stelestylis, Thoracocarpus.

Economic uses, etc. Carludovica leaves are made into Panama hats.

Illustrations.
• Technical details: Carludovica.
• Carludovica, Cyclanthus (inflorescences).