Melica L. is a genus of perennial grasses in the family Poaceae (subfamily Pooideae, tribe Meliceae), described by Carl Linnaeus in his Species Plantarum of 1753. Commonly called melic or melic grass, the genus contains over 100 accepted species distributed across temperate regions worldwide.
Plants in the genus are clumping to short-rhizomatous, with flowering culms that can reach up to 250 cm in height. A number of species produce corms at the base of their shoots, which has led to the informal name "oniongrass" for those members. The spikelets are characteristic and bead-like — reflected in the German common name Perlgräser (pearl grasses).
The genus is most diverse in South America and temperate Asia, with eight species endemic to China. In Europe, representatives such as M. ciliata, M. nutans, M. transsilvanica, and M. uniflora are widespread across temperate zones including Switzerland. In North America, the majority of species occur west of the Mississippi River, though M. mutica and M. nitens extend into the southeastern and lower Midwestern United States.
Molecular phylogenetic studies have confirmed the genus as monophyletic, resolving eight major infrageneric sections. Melica uniflora occupies the earliest-diverging position within the phylogeny. Most species are diploid with 2n = 18 chromosomes (base number x = 9); polyploidy is rare. Biogeographic evidence suggests the genus originated in Europe or western Asia and subsequently dispersed to produce geographically structured lineages across Eurasia, the Americas, and beyond.
Etymology
The Latin genus name Melica is reflected in the German common name Perlgräser, meaning "pearl grasses," a reference to the rounded, bead-like spikelets characteristic of many species in the genus. The English names "melic" and "melic grass" derive directly from the genus name established by Linnaeus in 1753.
Distribution
Melica is distributed across temperate regions on all major landmasses. The genus reaches its greatest diversity in South America and temperate Asia, with eight species endemic to China. In Europe, species such as M. ciliata, M. nutans, M. transsilvanica, and M. uniflora are well represented; Switzerland alone hosts four of these. In North America, most species are concentrated west of the Mississippi River, with M. mutica and M. nitens extending into the southeastern and lower Midwestern states.
Biogeographic analysis suggests the genus originated in Europe or western Asia and subsequently dispersed to establish geographically structured lineages across Eurasia, North America, and South America.
Ecology
Most Melica species are diploid, with 2n = 18 chromosomes and a base number of x = 9. Polyploidy occurs within the genus but remains uncommon. Genome sizes are generally small with moderate variation across phylogenetic lineages. Species tend to grow in temperate habitats, including woodland edges, grasslands, rocky slopes, and shaded banks, consistent with their wide distribution from European forests (M. uniflora) to Mediterranean and semi-arid slopes (M. ciliata).
Taxonomy
Melica L. was formally described by Carl Linnaeus in Species Plantarum: 66 (1753), placing it in the family Poaceae, subfamily Pooideae, tribe Meliceae. The genus holds accepted taxonomic status (GBIF usage key 2703093) with 149 descendant taxa recorded in the GBIF backbone. The Swiss national checklist (Info Flora) assigns it checklist number 1028679.
Recent molecular work has confirmed the genus as monophyletic. Eight major infrageneric sections have been identified through DNA sequence analysis, with Melica uniflora representing the earliest-diverging lineage. The type species is Melica nutans. In English the genus is known as "melicks" or "melic grass"; in German as Perlgräser (pearl grasses).
History
Melica was formally established by Carl Linnaeus in 1753 in Species Plantarum, the foundational work of modern plant nomenclature. The genus has since been recognized as a coherent, monophyletic group supported by molecular phylogenetic evidence. Biogeographic reconstruction suggests the group originated in Europe or western Asia and underwent long-distance dispersal events to colonize South America, temperate Asia, and North America, producing the geographically structured infrageneric sections recognized today.
