Anchusa L.

Scientific Description

Family Boraginaceae.

Habit and leaf form. Herbs; without essential oils. Autotrophic. Annual to perennial. Leaves basal and cauline. Plants with a basal concentration of leaves; to 0.6 m high. Helophytic, or mesophytic, or xerophytic. Leaves medium-sized; alternate; petiolate to subsessile, or sessile (above); non-sheathing; not gland-dotted; simple; epulvinate. Leaf blades dorsiventral, or isobilateral; entire; flat; linear to lanceolate; linear, or ovate, or obovate, or oblong; cross-venulate. Mature leaf blades adaxially pubescent; abaxially pubescent. Leaves without stipules. Leaf blade margins entire, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (broad-based). Urticating hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the disk. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. Inflorescences simple, or compound. The terminal inflorescence unit cymose (coiled at first). Inflorescences terminal, or axillary; scorpioid, simple or branched, sometimes raceme-like; not pseudanthial. Flowers pedicellate, or sessile; bracteate, or ebracteate; bracteolate; small; regular, or very irregular; when irregular zygomorphic; 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed. Calyx lobes markedly shorter than the tube to markedly longer than the tube. Calyx imbricate, or open in bud, or valvate; exceeded by the corolla, or more or less equalling the corolla; regular; neither appendaged nor spurred; persistent; accrescent. Calyx lobes ovate, or triangular, or linear. Corolla present; 5; 1 -whorled; appendiculate (with a corona of 5 scales from the throat protecting the nectar); gamopetalous; lobed. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate, or contorted; funnel-shaped, or tubular; regular, or unequal but not bilabiate (when tube curved or lobes unequal); glabrous abaxially; glabrous adaxially (scales papillose), or hairy adaxially (scales hairy); white, or blue. Corolla lobes ovate, or orbicular. Androecium present. Fertile stamens present. Androecial members definite in number. Androecium 5. Androecial members unbranched; adnate (to the corolla); all equal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion midway down the corolla tube, or in the throat of the corolla tube. Stamens all inserted at the same level; becoming exserted, or remaining included; all more or less similar in shape; isomerous with the perianth; oppositisepalous; filantherous (to subsessile), or with sessile anthers. Anthers all alike; dorsifixed to basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate; unappendaged. Gynoecium 2 carpelled. The pistil 4 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular (4-lobed); 2 locular (‘really’, but rarely ostensibly so), or 4 locular (ostensibly, via false septa). Locules secondarily divided by ‘false septa’. Gynoecium median; stylate. Styles 1; simple; from a depression at the top of the ovary; ‘gynobasic’; not becoming exserted. Stigmas 1; capitate. Placentation axile to basal. Ovules differentiated; 2 per locule (i.e. per true locule), or 1 per locule (per cell, when the gynoecium separating into one-ovuled portions); horizontal to ascending; epitropous; non-arillate; anatropous, or hemianatropous.

Fruit and seed features. Fruit aerial; fleshy, or non-fleshy; not spinose; a schizocarp. Mericarps 4; comprising nutlets. Seeds endospermic, or non-endospermic. Cotyledons 2. Embryo straight, or curved.

Special features. Corolla tube straight, or curved.

Etymology. From the Greek for "a paint for the skin"; a name used by Pliny for A. officinalis or A. tinctoria.