Lomelosia is a genus of 50–63 perennial and annual flowering plants in the family Caprifoliaceae, placed in the subfamily Dipsacoideae and the order Dipsacales. The genus ranges across the Old World, from the Mediterranean basin through the Middle East and Central Asia to Xinjiang in western China, with its greatest diversity concentrated in the eastern Mediterranean and the Middle East.
Plants in this genus are herbaceous or sometimes suffruticose — woody at the base but herbaceous above. Stems are leafy or scapiform and bear short hairs. Leaves may be sessile or stalked (petiolate), ranging from entire and toothed to deeply lobed (pinnatifid to pinnatisect), with basal leaves sometimes forming a rosette. The characteristic flower heads are hemispherical at anthesis and become globose to ovoid in fruit. Flowers are hermaphroditic, five-parted, and range in colour from pink and violet-pink to lavender-blue. The fruit is a dry achene, glabrous or hairy.
The defining morphological character of Lomelosia is the epicalyx tube bearing eight pits (foveolae) on its distal half — a feature that reliably separates it from the closely related genera Scabiosa, Sixalix, and Pterocephalus. For much of its taxonomic history the genus was subsumed within Scabiosa; it was formally reinstated by Rafinesque in 1838 but not widely accepted until comprehensive anatomical studies by Verlaque (1983) and Devesa (1984), followed by molecular phylogenetic analyses in the 1990s and 2000s, confirmed it as a distinct clade.
Several species are cultivated as ornamentals in European gardens, including L. caucasica, L. graminifolia, L. prolifera, and L. stellata. Some xerophytic species such as L. graminifolia and L. cretica are used in drought-tolerant landscaping, and L. prolifera has been trialled in green roof plantations.
Etymology
The name Lomelosia derives from the Greek word loma, meaning "the edge or the border," a reference to the membranous border of the flower. The genus was first formally published by the French-American botanist Constantine Samuel Rafinesque in Flora Telluriana, volume 4, page 95, in 1838, with Lomelosia stellata as the founding description.
Distribution
Lomelosia is an Old World genus distributed from the Mediterranean region to Central Asia and western China. In Europe it occurs in countries including Albania, Bulgaria, France, Greece, Italy, Portugal, Spain, and Ukraine; in North Africa across Algeria, Egypt, Libya, Morocco, and Tunisia; across the Middle East from Turkey and Lebanon through Iran, Iraq, and Pakistan; and in Central Asia including Kazakhstan, Tajikistan, Turkmenistan, and Uzbekistan. A few species extend east into Xinjiang, China. Greatest species diversity is concentrated in the eastern Mediterranean and the Middle East, including the Arabian Peninsula.
Ecology
The flowers of Lomelosia are insect-pollinated, with bees and bumblebees as the primary visitors, which receive nectar and pollen as a reward. Other recorded visitors include long-tongued hoverflies (Syrphidae), moths, butterflies (Lycaenidae), and other flies (Diptera). Species occupy a range of open habitats: dry slopes in garigue and open pine forest, arid meadows, detrital rocky slopes, stony hillsides, desert environments, and rocky cliff faces.
Taxonomy Notes
Lomelosia was long treated as part of Scabiosa L. and was included there by many authors, including Rechinger in the 1989 Flora Iranica. Following anatomical work by Verlaque (1983) and Devesa (1984), the Scabioseae subfamily was divided into several genera and Scabiosa caucasica was transferred to Lomelosia. Molecular data from De Castro & Caputo (1997–98) showed that Lomelosia (together with Pycnocomon) forms a clade distinct from Scabiosa and Sixalix; this was reinforced by carpological and palynological studies (Mayer & Ehrendorfer 1999) and later phylogenomic analyses (Caputo et al. 2004; Avino et al. 2009).
Cultivation
Propagation of Lomelosia has been achieved both by seed and by vegetative methods. Cutting propagation of L. hymettia using the rooting hormone indole-3-butyric acid (IBA) yielded rooting rates of 92.5–100% in autumn, compared with 50–67.5% in spring. In-vitro (tissue culture) propagation has been successfully applied to L. argentea. Several species are established ornamentals in European horticulture; L. stellata has naturalised as a casual escape in Belgium.
