Cucurbitaceae Juss.

Including Fevilleaceae Pfeiff., Nandhirob(ac)eae A. St-Hil., Nhandirob(ac)eae A. St-Hil. corr. Endl.

Habit and leaf form. Mostly more or less scandent, juicy herbs, or shrubs (rarely). Plants non-succulent. Annual, or perennial; with neither basal nor terminal aggregations of leaves; perennials in temperate regions tuberous. Climbing (mostly, or more or less trailing), or self supporting; tendril climbers (often, the tendrils representing modified shoots, usually one per node), or scrambling (the tendrils occasionally reduced to spines). Mesophytic to xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple, or compound; when compound ternate, or palmate. Lamina dissected, or entire; when simple/dissected, palmately lobed; usually palmately veined; cross-venulate. Leaves exstipulate; without a persistent basal meristem.

Leaf anatomy. Extra-floral nectaries often present. Hydathodes very commonly present. Stomata mainly confined to one surface (abaxial), or on both surfaces; anomocytic.

Lamina dorsiventral (usually), or isobilateral (sometimes). Cystoliths commonly present. Minor leaf veins without phloem transfer cells (Bryonia, Cucurbita).

Stem anatomy. Cork cambium present, or absent (?); initially deep-seated, or superficial. Nodes tri-lacunar. Primary vascular tissue in a cylinder, without separate bundles, or comprising a ring of bundles; nearly always bicollateral. Cortical bundles present (commonly), or absent. Medullary bundles absent. Internal phloem present (commonly), or absent. Secondary thickening developing from a conventional cambial ring, or anomalous; via concentric cambia (commonly), or from a single cambial ring. `Included' phloem present, or absent. Xylem with vessels. Vessel end-walls simple. Sieve-tube plastids S-type.

Reproductive type, pollination. Monoecious (commonly), or dioecious (commonly), or polygamomonoecious, or hermaphrodite (rarely). Entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in `inflorescences'. Inflorescences axillary. Flowers small to large; regular (usually), or somewhat irregular. The floral asymmetry most noticeably involving the androecium. Flowers cyclic; tetracyclic. Free hypanthium present.

Perianth with distinct calyx and corolla; (6-)10(-12); 2 whorled; isomerous. Calyx (3-)5(-6); 1 whorled; gamosepalous; regular; imbricate, or open in bud. Corolla (3-)5(-6); 1 whorled; polypetalous, or gamopetalous; more or less valvate; regular; green, or white, or yellow, or orange.

Androecium 5 (`essentially'), or 3 (ostensibly, by reduction and displacement). Androecial members branched and unbranched (commonly there are three stamens, two bifurcated and with two pairs of pollen sacs each, the other unbranched and conventional with two pollen sacs), or unbranched; usually adnate (to the hypanthium); variously coherent (by connate filaments, or in Cucurbita by cohesion of the anthers into a column), or free of one another; when coherent, commonly 1 - adelphous (i.e. all the stamens joined in a central column), or 2 - adelphous (4/1 in Thladiantha); 1 - whorled. Androecium exclusively of fertile stamens. Stamens 3, or 5; reduced in number relative to the adjacent perianth, or isomerous with the perianth. Anthers cohering (commonly), or connivent, or separate from one another; adnate; dehiscing via longitudinal slits; extrorse; unilocular, or unilocular and bilocular (often one unilocular, the others bilocular), or bilocular; bisporangiate, or bisporangiate and tetrasporangiate, or tetrasporangiate; appendaged (via the prolonged connective), or unappendaged. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with one middle layer, or initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; 3 - aperturate, or 4-15 - aperturate (to `many'); variously colpate, or porate, or colporate, or foraminate, or rugate; 2-celled.

Gynoecium 1 (Cyclanthereae), or (2-)3(-5). Carpels reduced in number relative to the perianth. Gynoecium monomerous, or syncarpous; of one carpel (Cyclanthereae), or synovarious, or synstylovarious, or eu-syncarpous; inferior. Ovary 1 locular, or 2-3(-5) locular (by joining of the usually intruded parietal placentae). Gynoecium stylate. Styles 1, or 2-3(-5); when more than one, partially joined; apical. Stigmas 1, or 2-3(-5) (one per carpel); commissural; each 2 - lobed (in association with the commissural position, suggestive of derivation from adjacent carpels); wet type, or dry type; papillate, or non-papillate; Group II type and Group III type. Placentation parietal (usually); when the ovary plurilocular, axile. Ovules in the single cavity when unilocular, (1-)3-100 (i.e. to `many'); when plurilocular (1-)3-50 per locule (?); pendulous, or horizontal, or ascending; non-arillate; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type, or Allium-type. Polar nuclei fusing only after one has been fertilized, or fusing simultaneously with the male gamete (?). Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Hypostase present, or absent. Endosperm formation nuclear. Endosperm haustoria present (usually), or absent; chalazal. Embryogeny onagrad.

Fruit fleshy (usually), or non-fleshy (sometimes); dehiscent (sometimes explosively so), or indehiscent; a berry (usually, most commonly in the form of a `gourd' (pepo) or an amphisarca), or a capsule, or a samara (rarely). Seeds non-endospermic; medium sized to large; often flattened, winged, or wingless. Cotyledons 2 (large, flat). Embryo achlorophyllous (9/11); straight.

Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Cyanogenic (rarely), or not cyanogenic. Alkaloids present (commonly), or absent. Iridoids absent. Proanthocyanidins absent. Flavonols present, or absent; kaempferol and quercetin, or quercetin. Ellagic acid absent (4 species, 4 genera). Saponins/sapogenins present. Aluminium accumulation not found. C3 and CAM. C3 recorded in Citrullus, Cucumis, Cucurbita. CAM recorded in Seyrigia, Xerosicyos.

Geography, cytology. Temperate (warm only), or sub-tropical to tropical. Wanting only in colder regions. X = 7-14.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren's Superorder Violiflorae; Violales. Cronquist's Subclass Dilleniidae; Violales. Takhtajan's Subclass Dilleniidae; Dillenianae; Violales. Species 640. Genera 120; Abobra, Acanthosicyos, Apodanthera, Benincasa, Bryonia, Cayaponia, Citrullus, Ctenolepis, Cucumis, Cucurbita, Cyclanthera, Dendrosicyos, Ecballium, Echinocystis, Fevillea, Gurania, Herpetospermum, Luffa, Lagenaria, Marah, Melothria, Momordica, Peperonium, Schizopepon, Sechium, Sicana, Sicyos, Telfairia, Thladiantha, Trichosanthes, Trochomeria, Xerosicyos, Zanonia, etc.

Review of family: Jeffrey 1980.

Economic uses, etc. Many sources of important edible fruits, e.g. Cucurbita, Cucumis, Lagenaria, Sechium (melons, cucumbers, etc.), and some are poisonous.

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