Common name. Melon. Family Cucurbitaceae.
Habit and leaf form. Herbs, or herbaceous climbers (or trailing). Annual, or perennial. Leaves cauline (ass.). Plants with neither basal nor terminal concentrations of leaves. Stem internodes solid (ass.). Rhizomatous. Climbing (or trailing); tendril climbers (simple, coiled distally). Tendrils simple. Mesophytic to xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple. Leaf blades dissected (to deeply palmately 3–5 lobed; lobes ovate to obovate); ovate (to broadly ovate); when simple/dissected, palmately lobed; palmately veined; cross-venulate; cordate. Leaves without stipules (tendrils stipular in position). Leaf blade margins entire (sinuate), or dentate (and denticulate, or lobulate). Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (usually hispid). Extra-floral nectaries absent.
Reproductive type, pollination. Fertile flowers hermaphrodite (rarely), or functionally male and functionally female, or functionally male, or functionally female. Unisexual flowers present (usually), or absent. Plants hermaphrodite (rarely), or monoecious, or dioecious. Female flowers solitary; with staminodes (3 staminodes), or without staminodes. Male flowers solitary, or aggregated in ‘inflorescences’; without pistillodes (ass.). Entomophilous.
Inflorescence and flower features. Flowers solitary (male and female), or aggregated in ‘inflorescences’ (male only); in racemes, or in fascicles (or clusters or pedunculate groups). Inflorescences axillary; male flowers solitary, in fascicles or in racemes; female flowers solitary or rarely in fascicles. Flowers pedicellate, or sessile (female flowers usually sessile); ebracteate (ass.); ebracteolate (ass.); small to large; regular; cyclic. Free hypanthium present; campanulate to turbinate (in male flowers), or urceolate (in female flowers, the lower part globular to ellipsoid and narrowed into a short neck, then expanded into a campanulate upper part); lower part in female flowers adnate to the ovary. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; blunt-lobed; imbricate, or open in bud; regular. Calyx lobes ovate (to subulate). Corolla present; 5; 1 -whorled; gamopetalous (deeply lobed to the calyx); more or less valvate; campanulate; regular; yellow. Corolla lobes elliptic, or ovate. Corolla members bilobed (more or less). Fertile stamens present, or absent. Androecial members definite in number. Androecium 3. Androecial members branched and unbranched, or unbranched; adnate (to the hypanthium); all equal (ass.); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 3; distinctly dissimilar in shape (uni/bilocular); reduced in number relative to the adjacent perianth; oppositisepalous (about the middle of the hypanthium or on the floral tube or on the calyx tube below the petals); filantherous (connective with expanded crest-like appendages). Filaments appendiculate. Anthers cohering, or connivent, or separate from one another; adnate; dehiscing via longitudinal slits; extrorse; unilocular (1 anther), or bilocular (2 anthers); bisporangiate, or bisporangiate and tetrasporangiate, or tetrasporangiate; appendaged (via the prolonged connective), or unappendaged. Fertile gynoecium present, or absent. Gynoecium 1 carpelled, or 2–5 carpelled. The pistil 1–3 celled. Gynoecium syncarpous; of one carpel, or synovarious, or synstylovarious, or eu-syncarpous; inferior. Ovary unilocular, or plurilocular; 1–3 locular. Gynoecium stylate. Styles 1; partially joined; apical. Stigmas 1; commissural; 3 - lobed. Placentation parietal; when the ovary plurilocular, axile. Ovules in the single cavity 20–50; 20–50 per locule (many); pendulous, or horizontal, or ascending; non-arillate; anatropous.
Fruit and seed features. Fruit (15–)20–120 mm long; 1.5–7 cm in diameter; fleshy (firm skin, hard rind); spinose, or not spinose; dehiscent, or indehiscent (rarely tardily opening in 3 valves); 20–100 seeded (many). Seeds non-endospermic; medium sized to large; winged, or wingless. Cotyledons 2 (large, flat). Embryo straight.
Etymology. From the Latin for "cucumber"; also applied to the melon and watermelon.