Croninia J.M.Powell

Scientific Description

Family Epacridaceae.

Habit and leaf form. Small shrubs; evergreen; leptocaul, or pachycaul. Helophytic to xerophytic. Leaves minute to small; alternate; spiral; ‘herbaceous’, or leathery; imbricate, or not imbricate; shortly petiolate; non-sheathing; simple. Leaf blades entire; flat; parallel-veined; cross-venulate, or without cross-venules. Leaves without stipules. Leaf blade margins flat. 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. Pollination mechanism unspecialized.

Inflorescence and flower features. Flowers solitary; axillary; bracteate. Bracts triangular, keeled. Flowers bracteolate. Bracteoles grading upwards in size to the sepals. Flowers small to medium-sized; fragrant, or odourless; regular; 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; intrastaminal; annular. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx 5; 1 -whorled; polysepalous; ciliolate on the margins; imbricate; regular; persistent. Corolla 5; 1 -whorled; gamopetalous. Corolla lobes markedly shorter than the tube. Corolla valvate; tubular (tube cylindrical); regular; hairy adaxially (with ornamented hairs, lobes shortly bearded on the upper surface); white; persistent, or deciduous. Corolla lobes triangular (thick and fleshy). Androecium 5. Androecial members adnate (to the corolla); all equal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion in the throat of the corolla tube. Stamens isomerous with the perianth; oppositisepalous; all alternating with the corolla members. Filaments glabrous; short, terete. Anthers linear; attached dorsally, immediately below the bifurcate apex; becoming inverted during development, their morphological bases ostensibly apical in the mature stamens; non-versatile; dehiscing via longitudinal slits (by a single median slit); finally introrse (inverting during development); bisporangiate; unappendaged. Pollen shed as single grains; without viscin strands. Gynoecium 5 carpelled. The pistil 5 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 5 locular. Gynoecium stylate. Styles 1; from a depression at the top of the ovary; apical; hairy. Stigmas 1; truncate. Placentation apical. Ovules 1 per locule; pendulous; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy (mesocarp thin and dry); hairy; indehiscent; a drupe. The drupes with one stone. Endocarp hard and bony. Seeds endospermic. Endosperm oily. Seeds wingless. Embryo well differentiated. Cotyledons 2. Embryo straight. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia. South-West Botanical Province.

Additional characters Prophylls numerous. Corolla lobes spreading (horizontally).