Elacholoma F.Muell. & Tate

Scientific Description

Family Scrophulariaceae.

Habit and leaf form. Mat-forming herbs. Annual; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Helophytic, or mesophytic. Leaves opposite; ‘herbaceous’, or leathery, or membranous; sessile; connate (by a ridge across the node); simple; epulvinate. Leaf blades entire; pinnately veined. Leaves without stipules. Leaf blade margins entire, or crenate, or serrate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), 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 aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; spike-like. Flowers bracteate; ebracteolate; small; somewhat irregular, or very irregular. The floral asymmetry involving the androecium. Flowers 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; toothed. Calyx lobes markedly shorter than the tube. Calyx erect; imbricate, or valvate; tubular; regular; persistent; with the median member posterior. Corolla present; 5; 1 -whorled; gamopetalous; lobed; toothed. Corolla lobes markedly shorter than the tube. Corolla imbricate, or valvate; tubular; more or less regular, or unequal but not bilabiate (the minute lobes unequal). Androecium 2. Androecial members adnate (to the corolla); all equal; coherent; 1 -whorled. Stamens 2; reduced in number relative to the adjacent perianth; oppositisepalous. Anthers cohering; dehiscing via longitudinal slits; introrse; unilocular; 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; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1; 2 - lobed (lobes terete, equal, receptive throughout, exserted). 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 septicidal (from the apex), or loculicidal (leaving the septa attached to the 2 valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute to small. Cotyledons 2. Embryo straight to curved. Testa reticulate.

Special features. Corolla tube exceeding the calyx.

Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, Queensland, and New South Wales.