Nesaea Kunth

Scientific Description

Family Lythraceae.

Habit and leaf form. Sub- shrubs, or herbs. Herbs annual, or perennial. Young stems cylindrical, or tetragonal. Helophytic to xerophytic. Leaves opposite, or whorled; subsessile, or sessile; gland-dotted, or not gland-dotted; simple. Leaf blades entire; elliptic, or oblong, or ovate, or linear; pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous, or heterostylous. Entomophilous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit cymose, or racemose. Inflorescences axillary. Flowers pedicellate; bracteolate; minute to medium-sized; regular; 4 merous, or 6 merous; pentacyclic. Floral receptacle developing an androphore, or with neither androphore nor gynophore. Free hypanthium present; campanulate, or globose; usually markedly ribbed; appendages conspicuous to absent. Hypogynous disk present, or absent. Perianth with distinct calyx and corolla; (3–)8–16(–32); 2 -whorled; isomerous. Calyx present; 4–6; 1 -whorled; gamosepalous; blunt-lobed; lobes valvate; tubular, or campanulate, or urceolate; unequal but not bilabiate, or regular; persistent. Epicalyx present, or absent. Corolla present; 4–6; 1 -whorled; polypetalous; plicate; unequal but not bilabiate, or regular; white, or pink, or purple. Petals ovate, or obovate, or orbicular; sessile. Androecial members definite in number. Androecium 4–12. Androecial sequence determinable, or not determinable. Androecial members when determinable, maturing centripetally; adnate (to the hypanthium, low down); all equal, or markedly unequal; free of one another; 1–3 -whorled (or several). Androecium exclusively of fertile stamens. Stamens 4–12; attached inside the hypanthium; reduced in number relative to the adjacent perianth to isomerous with the perianth to polystemonous; alternisepalous; inflexed in bud, or erect in bud. Anthers basifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 2–5 carpelled. The pistil 2–5 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 2–5 locular; sessile to stipitate. Gynoecium stylate. Styles 1; apical. Stigmas 1; capitate. Placentation axile. Ovules (1–)5–50 per locule; ascending, or horizontal; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules splitting irregularly, or septicidal. Seeds non-endospermic; wingless. Cotyledons 2. Embryo straight.

Etymology. From the Latin Nesaea, one of the nereids, sea-nymphs; or from the Greek for "island".