Linnaeoideae is a subfamily of the family

Caprifoliaceae The Caprifoliaceae or honeysuckle family is a clade of dicotyledonous flowering plants consisting of about 860 species in 33 to 42 genera, with a nearly cosmopolitan distribution. Centres of diversity are found in eastern North America and easte ...

. It was formerly treated as the separate family Linnaeaceae. Five or six genera are placed in the subfamily, which ranges from creeping to erect shrubs. Most genera and species are native to East Asia, particularly China. One genus is native to Mexico, and '' Linnaea borealis'' occurs around the Northern Hemisphere.

Description

Linnaeoideae consists of shrubby plants that are mainly deciduous, but may be evergreen. Some, such as ''Linnaea'', are creeping, others, such as ''Abelia'', may be up to tall. The usually paired flowers are surrounded by an 'epicalyx' – a structure resembling the calyx that is composed of

involucral bracts In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also look ...

. A

nectary Nectar is a viscous, sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, ...

is present inside the tube of the corolla. Two of the three or four

locule A locule (: locules) or loculus (; : loculi) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usually refers to a chamber within an ovary ...

s of the inferior

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

are sterile and are empty at maturity. There are four

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s. The fruit is an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

, topped by usually persistent sepals.

Taxonomy

The subfamily Linnaeoideae was erected by

Constantine Samuel Rafinesque Constantine Samuel Rafinesque-Schmaltz (; 22 October 178318 September 1840) was a French early 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ult ...

in 1820. In 1998, Anders Backlund raised it to the full family Linnaeaceae. The

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...

reduced it again to a subfamily of Caprifoliaceae, a position supported in a 2024 review of the systematics of the Caprifoliaceae.

Genera

Six genera were included in a 2015

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study of the subfamily. , the same genera were included by the Angiosperm Phylogeny Website, although two of them were synonymized. , all six genera were accepted by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

. *'' Abelia'' R.Br. *''

Diabelia ''Diabelia'' is a genus of flowering plants in the family Caprifoliaceae The Caprifoliaceae or honeysuckle family is a clade of dicotyledonous flowering plants consisting of about 860 species in 33 to 42 genera, with a nearly cosmopolitan dis ...

'' Landrein (may be treated as a synonym of ''Abelia'') *'' Dipelta'' Maxim. *'' Kolkwitzia'' Graebn. *'' Linnaea'' L. *'' Vesalea'' M.Martens & Galeotti Some older sources also include the genus '' Zabelia'', but this is excluded in other sources, which may place it in its own subfamily, Zabelioideae.

Phylogeny

A study published in 2015 included the following cladogram showing the possible relationships among the genera included in the subfamily. Four purely Asian genera formed a subclade, distinct from the circumboreal ''Linnaea'' and the Mexican ''Vesalea''.

Distribution

Linnaeoideae has a disjoint distribution. Four genera (''Abelia'', ''Diabelia'', ''Dipelta'', and ''Kolkwitzia'') are native to East Asia, primarily China. ''Vesalea'' is native to Mexico. The monospecific genus ''Linnaea'' has a very wide distribution throughout the subarctic and temperate Northern Hemisphere.

Cultivation

Some of the shrubby species are grown as ornamental plants. , five

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s of ''Abelia'' had gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

, as had one species of ''Dipelta'', one cultivar of ''Kolkwitzia'', and one species of ''Vesalea''. File:Abelia chinensis—flowers.jpg, '' Abelia chinensis'' File:Abelia spathulata ツクバネウツギ衝羽根空木やしろの森公園DSCF8779.JPG, ''

Diabelia spathulata ''Diabelia spathulata'', synonym ''Abelia spathulata'', is a species of flowering plant in the honeysuckle family (Caprifoliaceae). It is a shrub native to southern Korea and central and southern Japan. Three varieties are accepted. *''Diabelia ...

'' File:DipeltaFloribunda.jpg, '' Dipelta floribunda'' File:Kolkwitzia amabilis4.jpg, '' Kolkwitzia amabilis'' File:Linnaea borealis - Karen Dillman.jpg, '' Linnaea borealis'' File:Abelia floribunda (18154046245).jpg, '' Vesalea floribunda''

References

{{Taxonbar, from1=Q18674561, from2=Q134924 Caprifoliaceae Asterid subfamilies