Eremophila R.Br.

Scientific Description

Common name. Povertybushes. Family Myoporaceae.

Habit and leaf form. Small trees, or shrubs; deciduous; resinous (to viscid), or not resinous. Young stems cylindrical. To 0.2–8(–15) m high. Mesophytic, or xerophytic. Leaves small, or medium-sized; alternate, or opposite (rarely), or whorled (rarely); usually spiral; more or less leathery, or ‘herbaceous’; petiolate, or sessile; non-sheathing; gland-dotted; simple; epulvinate. Leaf blades entire; linear, or ovate, or obovate, or elliptic, or orbicular. Mature leaf blades glabrous, or pubescent, or scaly. Leaves without stipules. Leaf blade margins entire, or crenate, or serrate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent; glandular hairs present, or absent. Stem anatomy. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring.

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

Inflorescence and flower features. Flowers solitary (mostly), or aggregated in ‘inflorescences’; axillary. Inflorescence few-flowered. Flowers when aggregated, in cymes. The terminal inflorescence unit cymose. Inflorescences axillary; the flowers opening in succession. Flowers pedicellate, or subsessile, or sessile; ebracteate; small to medium-sized (12–33 mm long, i.e. longer than in Myoporum); nearly always somewhat irregular to very irregular; weakly to strongly zygomorphic; 5 merous; cyclic; tetracyclic. Free hypanthium absent. Perianth with distinct calyx and corolla; (9–)10; 2 -whorled; isomerous (usually), or anisomerous. Calyx present; 4 (rarely), or 5; 1 -whorled; polysepalous (usually), or gamosepalous (either slightly in basal part, or rarely forming a deep calyx tube); lobed; imbricate, or valvate; regular, or unequal but not bilabiate; green, or yellow, or red, or purple; persistent; accrescent (often), or non-accrescent; with the median member posterior. Sepals ovate, or obovate, or triangular. Corolla present; 5; 1 -whorled; gamopetalous; lobed; lobulate. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate; campanulate, or tubular (tube often curved); bilabiate; hairy abaxially, or glabrous abaxially; hairy adaxially, or glabrous adaxially; plain, or with contrasting markings; green, or white, or cream, or yellow, or orange, or red, or pink, or purple, or brown. Androecium present. Androecial members definite in number. Androecium 4, or 5 (rarely). Androecial sequence not determinable. Androecial members adnate (to the corolla tube); all equal (rarely), or markedly unequal (nearly always); free of one another; 1 -whorled. Androecium exclusively of fertile stamens (the upper, posterior member usually lacking). Stamens 4, or 5 (rarely); becoming exserted, or remaining included; nearly always didynamous; reduced in number relative to the adjacent perianth, or isomerous with the perianth (rarely); fertile stamens representing the posterior-lateral pair and the anterior-lateral pair; oppositisepalous. Filaments hairy, or glabrous. Anthers separate from one another, or connivent; dorsifixed; versatile; dehiscing via longitudinal slits; introrse; unilocular (the cells confluent). Gynoecium 2 carpelled. The pistil 2 celled, or 4 celled (by secondary segmentation of the locules). Carpels reduced in number relative to the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 2 locular. Locules secondarily divided by ‘false septa’, or without ‘false septa’. Gynoecium median. Ovary sessile. Gynoecium stylate. Styles 1 (straight or hooked); from a depression at the top of the ovary; apical; hairy, or hairless. Stigmas 1; 1–2 - lobed (? notched at apex); dry type; papillate; Group II type. Placentation axile, or apical, or axile to apical. Ovules (1–)2–3(–4) per locule; funicled; pendulous; non-arillate; anatropous.

Fruit and seed features. Fruit fleshy (rarely), or non-fleshy; hairy, or not hairy; indehiscent (but sometimes partially splitting near the apex); a drupe (drupe-like or dry; smooth, ribbed or rarely winged). The drupes with separable pyrenes (the segments one-seeded). Fruit 2–4 celled; 2–4 locular. Dispersal unit the seed. Fruit 2–12 seeded. Seeds 1–3 per locule. Seeds endospermic. Cotyledons 2. Embryo more or less straight. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found.

Special features. Corolla tube curved (usually, more or less), or straight. The upper lip of the corolla incorporating 2 members, the lower 3, or incorporating 4 members, the lower 1; (posterior, adaxial) lip of the corolla bilobed, or 4 lobed. Lower (abaxial) lip of the corolla entire, or 3 lobed.

Geography, cytology, number of species. X = 27.

Economic uses, etc. Eremophila species have been utilised widely by Australian aborigines as medicinal and cultural plants (Richmond, 1993). This genus has uses in areas of primary industry such as soil conservation, revegetation, horticulture and as a feedstock source. Eremophila can be considered a good source of flavones, some sesquiterpenes and a variety of diterpenes (Richmond & Ghisalberti, 1994).

Etymology. From the Greek for "lonely places, desert" and "to love".