Lindernia All.

Scientific Description

Family Scrophulariaceae.

Habit and leaf form. Herbs. Plants succulent, or non-succulent. Annual, or perennial. Leaves basal, or cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Young stems tetragonal. Stem internodes solid. To 0.6 m high. Helophytic, or mesophytic. Leaves minute to small; opposite, or alternate (rarely); when alternate spiral; ‘herbaceous’, or leathery, or membranous; petiolate, or sessile; simple; epulvinate. Leaf blades entire; linear, or ovate, or obovate, or elliptic, or orbicular; pinnately veined. Mature leaf blades adaxially glabrous, or pubescent, or villous; abaxially glabrous, or pubescent, or villous. Leaves without stipules. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present, or absent; glandular hairs present, or absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

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

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; axillary. Inflorescence few-flowered, or many-flowered. Flowers in racemes, or in spikes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary. Flowers pedicellate; bracteate; ebracteolate; small to large; very irregular; zygomorphic; not resupinate, or resupinate (L. hypandra); 4 merous, or 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 9, or 10; 2 -whorled; isomerous, or anisomerous. Calyx present; 5; 1 -whorled; polysepalous, or gamosepalous; lobed. Calyx lobes markedly longer than the tube. Calyx erect; imbricate, or valvate; regular; green, or pink, or purple, or brown; persistent; accrescent; with the median member posterior. Sepals elliptic, or ovate, or triangular. Calyx lobes ovate, or triangular. Corolla present; 4 (the posterior pair united), or 5; 1 -whorled; appendiculate (with internal flaps enclosing anthers), or not appendiculate; gamopetalous; lobed; imbricate, or valvate; funnel-shaped; bilabiate; glabrous abaxially; hairy adaxially, or glabrous adaxially; plain, or with contrasting markings; white, or pink, or purple, or blue. Androecium 2, or 4. Androecial members adnate (to the corolla); all equal (when only 2 members present), or markedly unequal (usually); free of one another; 1 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present 2; representing the posterior-lateral pair, or the anterior-lateral pair. Stamens 2, or 4; remaining included; when all members fertile, didynamous; reduced in number relative to the adjacent perianth; fertile stamens representing the posterior-lateral pair, or the anterior-lateral pair, or the posterior-lateral pair and the anterior-lateral pair; oppositisepalous. Filaments appendiculate (spurred), or not appendiculate. Anthers dehiscing via longitudinal slits; introrse; unilocular (by reduction of other cell), or bilocular (cells confluent, divergent, with or without awns); tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium non-petaloid; syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 2 locular. Gynoecium median; stylate. Styles 1; simple; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1, or 2; 2 - lobed (when single), or 1 - lobed. Placentation axile, or apical. Ovules 50 per locule (to ‘many’); pendulous to ascending; non-arillate; anatropous, or campylotropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules valvular (with the septum remaining attached to the inner column and separate from the valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute to small. Cotyledons 2. Embryo straight to curved.

Special features. Corolla tube exceeding the calyx; straight. The upper lip of the corolla incorporating 2 members, the lower 3; (posterior, adaxial) lip of the corolla entire, or bilobed. Lower (abaxial) lip of the corolla 3 lobed.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province and Eremaean Botanical Province.

Etymology. After Franz Balthasar von Lindern (1682–1755), a physician of Strasbourg and student of Alsatian botany.