Common name. Hounds tongues. Family Boraginaceae.
Habit and leaf form. Herbs; without essential oils. Autotrophic. Annual, or perennial. Leaves basal and cauline. Plants with a basal concentration of leaves; to 0.75 m high. Helophytic, or mesophytic, or xerophytic. Leaves medium-sized; alternate; petiolate to sessile; sheathing (in the basal rosette), or non-sheathing (above); not gland-dotted; simple; epulvinate. Leaf blades dorsiventral, or isobilateral; entire; flat; linear to lanceolate; ovate, or obovate; cross-venulate. Mature leaf blades adaxially pubescent; abaxially pubescent. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present. 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, or absent. Nectar secretion from basal nectary around ovary. Entomophilous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. Inflorescences simple. The terminal inflorescence unit cymose (coiled at first). Inflorescences terminal; scorpioid, with flowers loosely arranged; not pseudanthial. Flowers pedicellate; bracteate, or ebracteate; bracteolate; small; regular; 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 about the same length as the tube to markedly longer than the tube. Calyx imbricate, or open in bud, or valvate. Degree of gamosepaly, maximum length joined/total calyx length 0.25–0.5. Calyx neither appendaged nor spurred; persistent; accrescent. Calyx lobes elliptic, or triangular. 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. Corolla imbricate, or contorted; funnel-shaped; regular; glabrous abaxially; scales hairy adaxially, or glabrous adaxially; white, or pink, or blue. Corolla lobes oblong, or 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 near the base of the corolla tube, or midway down the corolla tube. Stamens all inserted at the same level; remaining included; all more or less similar in shape; isomerous with the perianth; oppositisepalous; filantherous (to subsessile). Filaments not appendiculate. Anthers all alike; dorsifixed to basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged, or unappendaged. The anther appendages mucro-like. 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; non-fleshy; spinose; a schizocarp. Mericarps 4; comprising achenes, or comprising nutlets, or comprising drupelets. Seeds endospermic, or non-endospermic. Cotyledons 2. Embryo straight, or curved.
Special features. Corolla tube straight.
Etymology. From the Greek for "dog" and "tooth"; translation of the French name of the plant, chiendent.