Lonicera L.

Scientific Description

Family Caprifoliaceae.

Description of L. japonica.

Habit and leaf form. Lianas; evergreen to deciduous (‘half-evergreen’). Stem internodes when young. Climbing; stem twiners. Twining clockwise. Mesophytic. Leaves medium-sized; opposite; ‘herbaceous’ to leathery; petiolate; connate, or not connate; simple; epulvinate. Leaf blades dorsiventral; entire; flat; ovate, or oblong, or elliptic; pinnately veined; cross-venulate. Leaves with stipules, or without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Stem anatomy. Nodes tri-lacunar. 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’. The terminal inflorescence unit cymose. Inflorescences axillary; in axillary pairs on young shoots, crowded towards the ends. Flowers bracteate (the peduncles bibracteate); (bi-) bracteolate; medium-sized (3–4 cm long); fragrant; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers 5 merous; tetracyclic. Free hypanthium absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; toothed; imbricate, or open in bud; exceeded by the corolla; regular; persistent; with the median member posterior. Corolla present; 5; 1 -whorled; gamopetalous; lobed. Corolla lobes about the same length as the tube (the tube about as long as the limb). Corolla imbricate; tubular; bilabiate; hairy abaxially; white to cream, or cream to yellow, or white and purple, or yellow and purple (often purple outside at least when young); deciduous. Androecial members definite in number. Androecium 5. Androecial sequence not determinable. Androecial members adnate (epipetalous); markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion near the base of the corolla tube, or midway down the corolla tube, or in the throat of the corolla tube. Stamens didynamous, or not didynamous, not tetradynamous; isomerous with the perianth; oppositisepalous; all alternating with the corolla members. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; bilocular; tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; eu-syncarpous; inferior. Ovary plurilocular; 2 locular. Gynoecium stylate. Styles 1; simple; apical; much longer than the ovary at anthesis. Stigmas 1; capitate; dry type; papillate; Group III type. Placentation axile. Ovules 8–50 per locule (‘many’); pendulous; apotropous; with dorsal raphe; anatropous.

Fruit and seed features. Fruit fleshy; black; indehiscent; a berry; 2 celled; 2 locular. Seeds endospermic. Endosperm ruminate, or not ruminate; oily. Cotyledons 2. Embryo achlorophyllous; straight. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Adventive. A genus of about 200 species; 1 species in Western Australia; L. japonica.

Economic uses, etc. A noxious weed.

Etymology. After Adam Lonitzer (1528–86), German naturalist.