Asyneuma is a genus of flowering plants in the bellflower family, Campanulaceae, placed in the order Asterales. The genus comprises up to about 33 recognised species of herbaceous perennials distributed across North Africa and Eurasia, with a particularly strong centre of diversity in Turkey, where many species are endemic. The range extends westward into the Balkans and Italy, eastward through the Caucasus and Middle East into Iran and Iraq, and further into Central Asia, the Indian Subcontinent, China, and East Asia as far as Japan and Korea.
Plants of the genus are characterised by a wheel-shaped (rotate) corolla in which the petals are fused at their bases and spread outward into very narrow, strap-like lobes — a flower shape that contrasts with the more bell-shaped corollas typical of many other campanulaceous genera. The calyx bears absent or only rudimentary appendages, the stigma is 2–4-lobed, and the fruit is an oblong or roughly spherical capsule that opens via pores on the sides. These morphological characters place Asyneuma close to the large genus Campanula, and the boundary between the two has long been disputed: some authors weight the degree of petal fusion as the decisive character, while others favour the position of the capsule pores. Molecular studies have been necessary to resolve the placement of ambiguous species.
Plants in the genus are sometimes called harebells, though this common name is more broadly applied across the Campanulaceae family as a whole.
Distribution
Asyneuma is native to North Africa and Eurasia, with the greatest species diversity centred on Turkey, where many members are endemic. The range extends across the Balkans, Caucasus, the Middle East (Iran, Iraq, Syria, Lebanon), Central Asia, the Indian Subcontinent, southwestern China, and East Asia including Japan and Korea. A few species reach the Greek islands, Algeria, and the Sinai Peninsula.
Taxonomy Notes
The genus is closely related to Campanula, and the circumscription of Asyneuma has been contentious. Authors differ on whether the degree of corolla-lobe fusion or the position of capsule dehiscence pores should be treated as the primary diagnostic character, leading to disagreements over which species belong in Asyneuma versus Campanula. Molecular phylogenetic data has been required to resolve placement for several species.
