Gratiola L.

Scientific Description

Common name. Brooklimes. Family Scrophulariaceae.

Habit and leaf form. Herbs. Perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; to 0.5 m high. Hydrophytic, or helophytic, or mesophytic; when hydrophytic, rooted. Leaves minute to medium-sized; opposite; ‘herbaceous’, or leathery, or membranous; subsessile to sessile (or stem-clasping); simple; epulvinate. Leaf blades entire; ovate, or oblong, or elliptic; pinnately veined. Mature leaf blades adaxially glabrous, or pubescent; abaxially glabrous, or pubescent. Leaves without stipules. Leaf blade margins entire, or serrate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present, or absent; glandular hairs present, or absent; complex 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; in racemes and in spikes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; open, leafy. Flowers pedicellate to sessile; bracteate; bracteolate; small to medium-sized; very irregular; zygomorphic; 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 (sepals more or less equal or unequal); imbricate, or valvate; persistent; accrescent; with the median member posterior. Sepals ovate, or linear. Corolla present; 4 (the posterior pair united), or 5; 1 -whorled; gamopetalous; lobed. Corolla lobes markedly shorter than the tube. Corolla imbricate, or valvate; tubular; slightly bilabiate; hairy adaxially (at the throat); plain, or with contrasting markings; white, or yellow, or pink, or purple. Androecium 2, or 4. Androecial members adnate (to the corolla); all equal, or markedly unequal (when minute staminodes present); free of one another; 1 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present 2; representing the anterior-lateral pair. Stamens 2; remaining included; reduced in number relative to the adjacent perianth; fertile stamens representing the posterior-lateral pair; oppositisepalous. Anthers dehiscing via longitudinal slits; introrse; bilocular (cells connivent); 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; persistent, or deciduous. Stigmas 1; 1 - lobed, or 2 - 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; not spinose; dehiscent; a capsule. Capsules septicidal, loculicidal, and valvular (opening from the central axis by 4 valves). Fruit 2 celled; 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute. Cotyledons 2. Embryo straight to curved. Testa striate-reticulate.

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, South Australia, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania. South-West Botanical Province.

Etymology. From the Greek for "anything drawn or written" and -ites, suffix implying belonging or connection; refers to the sori, crowded in lines, like writing.