Passifloraceae Juss.

Habit and leaf form. Trees and shrubs, or lianas (and herbaceous climbers). Self supporting, or climbing; the climbers tendril climbers (the tendrils axillary, perhaps representing modified inflorescences). Mesophytic, or xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple, or compound (e.g. in Deidamia, Passiflora); when compound, palmate. Lamina when simple dissected, or entire; when dissected, palmately lobed; pinnately veined, or palmately veined; cross-venulate. Leaves stipulate, or exstipulate. Stipules when present, free of one another; usually small, caducous. Leaves without a persistent basal meristem.

Leaf anatomy. Extra-floral nectaries present (on the petioles). Mucilaginous epidermis present, or absent. Stomata anomocytic.

The mesophyll with sclerencymatous idioblasts, or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (Passiflora).

Stem anatomy. Nodes tri-lacunar. Internal phloem absent. Secondary thickening developing from a conventional cambial ring (?), or anomalous; in Adesmia, via concentric cambia. `Included' phloem present, or absent (?). Xylem with fibre tracheids; with libriform fibres, or without libriform fibres. Vessel end-walls simple, or scalariform and simple. Wood parenchyma typically apotracheal. Sieve-tube plastids S-type.

Reproductive type, pollination. Hermaphrodite (usually), or dioecious (e.g. in Adenia), or polygamomonoecious (?). Entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in `inflorescences'; in cymes. The terminal inflorescence unit cymose. Inflorescences axillary. Flowers usually three bracteate; large; regular; (3-)5(-8) merous; cyclic. Floral receptacle developing an androphore (often), or with neither androphore nor gynophore; markedly hollowed (often), or not markedly hollowed (the receptacle variously shaped). Free hypanthium present (usually), or absent. Hypogynous disk often present (staminodial), or absent.

Perianth with distinct calyx and corolla, or sepaline (C rarely lacking); 5, or 6-16; usually 2 whorled; isomerous. Calyx (3-)5(-8); 1 whorled; polysepalous, or gamosepalous (basally); regular; persistent; imbricate. Corolla (3-)5(-8); 1 whorled; appendiculate (with a conspicuous staminodal `corona', this consisting of threadlike filaments or scales, or annular); polypetalous, or gamopetalous (the petals sometimes shortly united basally); imbricate; regular.

Androecium 5, or 20-60. Androecial members free of the perianth; united with the gynoecium (at least, often inserted on the gynophore), or free of the gynoecium; free of one another, or coherent; sometimes 1 - adelphous (the stamens of Androsiphonia connate around the gynophore); 1 - whorled (?-when staminodes absent), or 2 - whorled, or 3 - whorled. Androecium including staminodes (always?). Staminodes 15-50 (usually `many' atop the hypanthium within the corolla, constituting the conspicuous petaloid `corona', or of filaments, or sometimes represented by a disk around the gynoecium); petaloid, or non-petaloid, or petaloid and non-petaloid. Stamens (4-)5(-10); isomerous with the perianth, or diplostemonous. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; 3-12 - aperturate; colporate (to colpoidorate); 2-celled.

Gynoecium (2-)3(-5). Carpels reduced in number relative to the perianth to isomerous with the perianth. Gynoecium syncarpous; synovarious to eu-syncarpous; superior. Ovary 1 locular; stipitate. Styles 1, or (2-)3(-5); free to partially joined; apical. Stigmas 1, or (2-)3(-5); dry type; papillate, or non-papillate; Group II type. Placentation parietal. Ovules in the single cavity 7-100 (`several to many'); arillate; orthotropous to 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 (sometimes with filiform apparatus). Endosperm formation nuclear. Embryogeny onagrad, or piperad (occasionally).

Fruit dehiscent, or indehiscent; a capsule, or a berry. Seeds endospermic. Endosperm ruminate (P. foetida), or not ruminate; oily. Embryo well differentiated. Cotyledons 2. Embryo achlorophyllous (1/1); straight.

Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Often cyanogenic, or not cyanogenic. Cynogenic constituents of the gynocardin group. Alkaloids present (commonly), or absent. Iridoids absent. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (3 species of Passiflora). Saponins/sapogenins present, or absent. Aluminium accumulation not found. C3 and CAM. C3 recorded in Passiflora. CAM recorded in Adenia.

Geography, cytology. Sub-tropical to tropical. Pantropical and subtropical. X = 6, 9-11.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren's Superorder Violiflorae; Violales. Cronquist's Subclass Dilleniidae; Violales. Takhtajan's Subclass Dilleniidae; Dillenianae; Violales. Species 530. Genera about 18; Adenia, Ancistrothyrsus, Androsiphonia, Barteria, Basananthe, Crossostemma, Deidamia, Dilkea, Efulensia, Hollrungia, Mitrostemma, Paropsia, Paropsiopsis, Passiflora, Schlechterina, Smeathmannia, Tetrapathaea, Tryphostemma, Viridivia.

Economic uses, etc. Edible berries (`passion fruit') from Passiflora spp., cultivated ornamental climbers.

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