Reseda L.

Scientific Description

Common name. Mingonettes. Family Resedaceae.

Habit and leaf form. Herbs. Annual, or perennial. Leaves basal and cauline (basal leaves often rosetted or somewhat clustered), or cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Stem internodes solid. Mesophytic, or xerophytic. Leaves alternate; spiral; petiolate to sessile; non-sheathing; simple; epulvinate. Leaf blades dissected (3 lobed, pinnatifid), or entire; when dissected pinnatifid, or palmately lobed; one-veined, or pinnately veined; decurrent. Leaves with stipules (small, modified to glands). Stipules intrapetiolar; free of one another; represented by glands. Leaf blade margins entire. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present. Extra-floral nectaries present (small glands on either side near the base of cauline leaves). Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit racemose. Inflorescences terminal; racemes. Flowers pedicellate (ribbed); bracteate; ebracteolate; small to medium-sized; very irregular. The floral asymmetry involving the perianth and involving the androecium. Floral receptacle developing an androphore (with the extra-staminal disk more strongly developed posticously). Free hypanthium absent. Perianth with distinct calyx and corolla; 7–11(–16); 2 -whorled; anisomerous (often), or isomerous. Calyx present; 4–8 (4–6); 1 -whorled; polysepalous; imbricate (slightly), or valvate; unequal but not bilabiate, or regular; persistent. Sepals elliptic to ovate, or linear. Corolla present; 3–8 (3–5); 1 -whorled; polypetalous; valvate, or with open aestivation; with the outer members usually progressively smaller and with fewer appendages; white (white-cream), or yellow (yellow-cream); persistent, or deciduous. Petals clawed. Corolla members fringed, or deeply bifid (at least the innermost, largest). Androecial members definite in number. Androecium 12–25. Androecial sequence determinable, or not determinable. Androecial members theoretically maturing centrifugally; free of the perianth; markedly unequal (the posterior members shorter), or all equal; free of one another. Androecium exclusively of fertile stamens. Stamens 12–25 (usually); all more or less similar in shape; isomerous with the perianth to polystemonous. Anthers versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium (2–)3–6(–7) carpelled. The pistil 1 celled. Gynoecium syncarpous (at base); synovarious; superior. Ovary unilocular; 1 locular. The ‘odd’ carpel posterior. Ovary sessile. Gynoecium non-stylate. Styles apical. Stigmas 3 (or 4); commissural, or dorsal to the carpels and commissural. Placentation parietal. Ovules in the single cavity 5–100; numerous; pendulous, or ascending; with ventral raphe; arillate, or non-arillate; hemianatropous, or campylotropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; capsular-indehiscent (but apically open); 1 celled; numerous. Seeds more or less non-endospermic; reniform. Embryo well differentiated; curved, or bent.

Physiology, biochemistry. Mustard-oils present.

Special features. The young, syncarpous unilocular gynoecium and later the capsule open.

Geography, cytology, number of species. 70 species.

Etymology. From the Latin for "white mignonette", R. alba, from the word for "to heal, assuage"; the plant was used as a balm for bruises.