Luffa Mill.

Scientific Description

Common name. Loofah. Family Cucurbitaceae.

Habit and leaf form. Herbaceous climbers. Annual. Leaves cauline (ass.). Plants with neither basal nor terminal concentrations of leaves. Young stems more or less glabous. Stem internodes solid (ass.). Climbing; tendril climbers (2 to many branched, spiralling above point of branching). Tendrils branched. Mesophytic to xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple. Leaf blades dissected (palmately 3–5 lobed); ovate; when simple/dissected, palmately lobed; palmately veined; cross-venulate; cordate. Leaves without stipules (tendrils stipular in position). Leaf blade margins dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent (leaves hairy).

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Unisexual flowers present. Plants monoecious. Female flowers solitary; with staminodes (3 staminodes). Male flowers aggregated in ‘inflorescences’; with pistillodes. Entomophilous.

Inflorescence and flower features. Flowers solitary (female flowers), or aggregated in ‘inflorescences’ (males); in racemes. Inflorescences axillary; male flowers rarely solitary; female flowers usually solitary, sometimes co-axillary with male flowers. Flowers pedicellate; bracteate (male flowers, pedicels subtended by small, glandular bracts), or ebracteate (female flowers); probracts present; small to large; regular; cyclic. Free hypanthium present; campanulate (in male flowers), or urceolate (in female flowers, the lower part narrowed into a short neck and expanded above into a campanulate upper part); of female flowers adnate to the ovary in the lower part. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; toothed; imbricate, or open in bud; campanulate (or turbinate); regular. Corolla present; 5; 1 -whorled; polypetalous; more or less valvate; regular; white, or yellow. Petals oblong to obovate (or obcordate). Corolla members entire. Fertile stamens present, or absent. Androecial members definite in number. Androecium 3–5. Androecial members branched and unbranched, or unbranched; adnate (to the hypanthium); all equal (ass.); free of one another, or coherent (all free, or 2 connate and the third free); 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; all more or less similar in shape, or distinctly dissimilar in shape; reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous (towards base of hypanthium or on calyx tube below petals). Anthers cohering, or connivent, or separate from one another; adnate; dehiscing via longitudinal slits; extrorse; unilocular (1 when stamens 3), or bilocular (2 when stamens 3, all when stamens 5); bisporangiate, or bisporangiate and tetrasporangiate, or tetrasporangiate; appendaged (via the prolonged connective), or unappendaged. Fertile gynoecium present, or absent (from male flowers). 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 3; commissural; 2 - lobed. Placentation parietal; when the ovary plurilocular, axile. Ovules in the single cavity 20–50; 20–50 per locule (numerous); pendulous, or horizontal, or ascending; non-arillate; anatropous.

Fruit and seed features. Fruit 25–150 mm long; 2–7 cm in diameter; fleshy, or non-fleshy (when ripe); spinose, or not spinose; dehiscent; a capsule, or a berry (a pepo). Capsules circumscissile. Fruit 20–100 seeded (many). Seeds non-endospermic; medium sized to large; winged, or wingless. Cotyledons 2 (large, flat). Embryo straight.

Etymology. From the Arabic lufa, name of the plant; L. cylindrica has cylindrical fruit, the fibrous interior of which used to provide bath sponges or loofahs.