Fallopia Adans.

Scientific Description

Family Polygonaceae.

Habit and leaf form. Herbaceous climbers. Annual, or perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Climbing (or decumbent); stem twiners. Helophytic, or mesophytic, or xerophytic. Leaves alternate, or opposite; spiral; ‘herbaceous’; petiolate (petiole basally with small pit nectaries); sheathing. Leaf sheaths not tubular; with free margins. Leaves gland-dotted, or not gland-dotted; simple; sometimes almost peltate, or not peltate; epulvinate. Leaf blades entire; pinnately veined; cross-venulate; cordate, or sagittate. Leaves with stipules. Stipules intrapetiolar; concrescent; ochreate; scaly. Leaf blade margins entire (or crisped), or crenate; flat, or revolute. Leaves without a persistent basal meristem. Stem anatomy. Nodes penta-lacunar to multilacunar. Secondary thickening absent, or developing from a conventional cambial ring, or anomalous.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Anemophilous, or entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescences terminal, or axillary; paniculate or flowers in clusters in leaf axils; with involucral bracts, or without involucral bracts. Flowers small; regular; 2 merous, or 3 merous; cyclic to partially acyclic. When partially acyclic, the perianth acyclic and the androecium acyclic. Free hypanthium present, or absent. Hypogynous disk present (or nectaries present between the androecial members); annular. Perianth ambiguously with distinct calyx and corolla, or sepaline, or petaline, or of ‘tepals’ (depending on interpretation); 5; 2 -whorled; free to joined; similar in the two whorls, or different in the two whorls; non-fleshy; persistent; accrescent (usually, the outer perianth segments enlarging and becoming thin-winged or keeled in fruit). Androecium (2–)6(–9). Androecial members branched, or unbranched; free of the perianth, or adnate (usually more or less perigynous ?); all equal, or markedly unequal; free of one another, or coherent (filaments basally connate ?); when cyclic, 2 -whorled (3+3, or spiralled). Androecium exclusively of fertile stamens. Stamens (2–)6(–9). Anthers dorsifixed, or basifixed; versatile, or non-versatile; dehiscing via longitudinal slits; introrse, or extrorse and introrse, or latrorse; tetrasporangiate. Gynoecium (2–)3 carpelled. The pistil 1 celled. Carpels isomerous with the perianth (when P cyclic). Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary unilocular; 1 locular. Locules secondarily divided by ‘false septa’ (or incompletely trilocular by false septa), or without ‘false septa’. The ‘odd’ carpel posterior. Gynoecium stylate (sometimes only shortly). Styles (2–)3; free to partially joined; apical. Stigmas (2–)3; capitate, or peltate; dry type; papillate (very shortly fimbriate), or non-papillate; Group II type. Placentation basal. Ovules in the single cavity 1; funicled, or sessile; ascending; non-arillate; orthotropous to anatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; a nut (trigonous or two-sided), or achene-like; 1 seeded. Seeds endospermic. Endosperm ruminate, or not ruminate; oily. Perisperm present to absent (‘more or less absent’ ?). Seeds with starch. Cotyledons 2. Embryo straight to curved. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Plants accumulating free oxalates. Photosynthetic pathway: C₃ and C₄.

Geography, cytology, number of species. N = 10, 11.