Buchnera L.

Scientific Description

Common name. Blackrod. Family Scrophulariaceae.

Habit and leaf form. Herbs (mostly), or shrubs. ‘Normal’ plants, or plants of very peculiar form (parasitic). Partially parasitic. On roots of the host. Annual, or perennial. Leaves basal and cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; to 1 m high. Self supporting. Helophytic, or mesophytic, or xerophytic. Leaves opposite, or alternate and opposite (alternate above); when alternate spiral, or four-ranked; ‘herbaceous’, or leathery; petiolate to sessile; not connate; non-sheathing; simple; epulvinate. Leaf blades entire; linear, or ovate, or obovate, or oblong, or elliptic; pinnately veined. Mature leaf blades adaxially glabrous, or scabrous, or pubescent; abaxially glabrous, or scabrous, or pubescent. 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. Hairs present, or absent; glandular hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous. Pollination mechanism conspicuously specialized (with a loose-pollen mechanism), or unspecialized.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescence many-flowered. Flowers in racemes. Inflorescences simple. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; spike-like. Flowers pedicellate to sessile; bracteate; bracteolate; small to medium-sized; very irregular; zygomorphic; 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; toothed. Calyx lobes markedly shorter than the tube. Calyx prominently 10 veined; erect; imbricate, or valvate. Degree of gamosepaly, maximum length joined/total calyx length greater than 0.5. Calyx tubular; unequal but not bilabiate (tube bent); persistent; accrescent; with the median member posterior. Calyx lobes triangular. Corolla present; 5; 1 -whorled; gamopetalous. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate, or valvate; tubular (to salverform); unequal but not bilabiate (lobes subequal); glabrous abaxially; hairy adaxially (at apex of tube), or glabrous adaxially; plain, or with contrasting markings; white, or cream, or pink, or purple, or blue; not spurred. Corolla lobes obovate. Androecial members definite in number. Androecium 4. Androecial members adnate (to the corolla); markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4; remaining included; didynamous; reduced in number relative to the adjacent perianth; oppositisepalous. Anthers separate from one another; dehiscing via longitudinal slits; introrse; unilocular (by abortion of 1 cell); tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium non-petaloid; syncarpous; 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; 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 loculicidal (with the septum remaining attached to the 2 valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute to small; wingless. Cotyledons 2. Embryo straight to curved.

Special features. Corolla tube exceeding the calyx; straight, or curved (slightly).

Geography, cytology, number of species. Paleotropical, Neotropical, and Australian. 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 Johann Gottfried Buechner (1695–1749), German botanist who studied the plants of Saxony.