Convallaria is a small genus of rhizomatous herbaceous perennial plants in the family Asparagaceae (order Asparagales), subfamily Convallarioideae, commonly known as lily-of-the-valley. The genus contains three species native to temperate regions of Eurasia and the east-central United States.
Plants form extensive spreading colonies through underground rhizomes and stolons. Stems typically reach 15–35 cm in height and bear two or, rarely, three leaves. The flowering stems carry a one-sided raceme of six to twelve pendulous, bell-shaped flowers with six fused white tepals, distinctively sweetly scented and appearing in late spring, typically May to June in the Northern Hemisphere. The fruit is a small orange-red berry containing cardiac glycosides (cardenolides) that render all parts of the plant highly toxic to humans and most animals.
The three currently recognised species are Convallaria majalis (Europe and western Asia), Convallaria keiskei (eastern Asia, with bowl-shaped flowers and red fruit), and Convallaria pseudomajalis (the southern Appalachian Mountains of eastern North America). These were formerly treated as varieties of C. majalis but are now regarded as distinct species. The genus was placed in the APG III system within Asparagaceae, subfamily Convallarioideae, having previously been classified in Ruscaceae, Convallariaceae, and Liliaceae in succession as botanical understanding evolved.
Convallaria majalis, the best-known member of the genus, has a long history in European culture as a symbol of the return of happiness and spring; it is the national flower of Finland. The fragrance of the flowers has been widely imitated in perfumery under the French name muguet.
Etymology
The genus name Convallaria derives from Botanical Latin meaning "valley," reflecting the plant's characteristic natural habitat in shaded woodland valleys. The common name lily-of-the-valley has been in use in English since at least the 16th century; in pre-modern England the plant was also called glovewort (used to make a salve for sore hands) and Apollinaris, from a legend that it was discovered by Apollo.
Distribution
Convallaria species are native to temperate regions of Europe (largely excluding the Mediterranean margin), Western and Northern Asia, and the east-central to southern United States (Appalachian Mountains region). As a genus, the distribution spans temperate Eurasia and eastern North America, with each of the three species occupying a distinct part of this range. C. majalis is absent from Ireland as a native species, though it is naturalised there.
Ecology
Convallaria grows in partial shade and prefers warm summers with moist, humus-rich soils — silty, sandy, or occasionally wet fen soils, in both acidic and alkaline conditions. In Britain the species occurs from sea level to around 490 m; in central and southern Europe it reaches up to 2,300 m altitude. Plants spread aggressively by rhizomes, and single-clone colonies are self-incompatible and cannot set seed without genetic partners. The foliage and berries are used as food by certain Lepidoptera larvae and the leaf beetle Lilioceris merdigera, which can tolerate the plants' cardenolide toxins.
Taxonomy Notes
The genus Convallaria was described by Linnaeus in Sp. Pl. in 1753 (authorship: L.) and has moved between several family placements as monocot systematics developed. It was formerly placed in Liliaceae, then Convallariaceae, then Ruscaceae, and is now classified in Asparagaceae, subfamily Convallarioideae, under the APG III system. What was formerly treated as a single wide-ranging species (C. majalis) with three varieties is now resolved into three distinct species: C. majalis sensu stricto, C. keiskei, and C. pseudomajalis.
Cultural Uses
The lily-of-the-valley has been significant in European culture for centuries. It is the national flower of Finland (designated 1967) and was formerly the national flower of Yugoslavia. In the Victorian "language of flowers" it symbolises the return of happiness. The scent of the flowers — sold under the French name muguet — is one of the most widely replicated in commercial perfumery. The plant has a long history of folk medicinal use, though no scientific evidence supports efficacy for any human disease.
