Honeysuckles are arching shrubs or twining vines in the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in North America and Eurasia. Widely known species include Lonicera periclymenum, Lonicera japonica and Lonicera sempervirens. L. japonica is an aggressive, highly invasive species considered as a significant pest on the continents of North America, Europe, South America, Australia, and Africa. Some species are highly fragrant and colorful, so are cultivated as ornamental garden plants. In North America, hummingbirds are attracted to the flowers, especially L. sempervirens and L. ciliosa. Honeysuckle derives its name from the edible sweet nectar obtainable from its tubular flowers. The name Lonicera stems from Adam Lonicer, a Renaissance botanist.
Description
Most species of Lonicera are hardy twining climbers, with a minority of shrubby habit. Some species are tender and can only be grown outside in subtropical zones. The leaves are opposite, simple oval, 1-10 cm long; most are deciduous but some are evergreen. Many of the species have sweetly scented, bilaterally symmetrical flowers that produce a sweet, edible nectar, and most flowers are borne in clusters of two. Both shrubby and vining sorts have strongly fibrous stems which have been used for binding and textiles. The fruit is a red, blue or black spherical or elongated berry containing several seeds; in most species the berries are mildly poisonous, but in a few they are edible and grown for home use and commerce. Most honeysuckle berries are attractive to wildlife, which has led to species such as L. japonica and L. maackii spreading invasively outside of their home ranges. Many species of Lonicera are eaten by the larvae of some Lepidoptera species—see a list of Lepidoptera that feed on honeysuckles.
The spread of L. japonica in North America began in the United States in 1806, when it was widely cultivated by the 1860s. It was first discovered in Canada in Ontario forests in 1976, and became invasive by 2007. L. japonica was introduced in Australia between 1820-40. Several species of honeysuckle have become invasive when introduced outside their native range, particularly in North America, Europe, South America, Australia, and Africa. Invasive species include L. japonica, L. maackii, L. morrowii, L. tatarica, and the hybrid between the last two, L. × bella.
Cultivation
Honeysuckles are valued as garden plants, for their ability to cover unsightly walls and outbuildings, their profuse tubular flowers in early summer, and the intense fragrance of many varieties. The hardy climbing types need their roots in shade, and their flowering tops in sunlight or very light shade. Varieties need to be chosen with care, as they can become substantial. Cultivars of the dense, small-leaved L. nitida are used as low, narrow hedges. The following hybrids have gained the Royal Horticultural Society's Award of Garden Merit:
Honeysuckle is renowned for its colorful, fragrant flowers and variously colored fruit, indicating the presence of complex phytochemicals underlying these properties. Component analyses of berries from 27 different cultivars and 3 genotypes of edible honeysuckle showed the presence of iridoids, anthocyanins, flavonols, flavanonols, flavones, flavan-3-ols, and phenolic acids. While sugars determine the level of sweetness in the berries, organic acids and polyphenols are responsible for the sour taste and tartness. Some 51 of the same compounds in berries are found in flowers, although the proportions of these compounds varied among cultivars studied.
Interaction with other species
Many insects in the order Lepidoptera visit honeysuckles as a food source. An example of this is the moth Deilephila elpenor. This nocturnal species of moth is primarily attracted to honeysuckles, and they visit the flowers at night to feed on their nectar.
