Eragrostis is a large, cosmopolitan genus of grasses in the family Poaceae, traditionally placed in subfamily Chloridoideae and serving as the type genus of tribe Eragrostideae. The name combines the Greek érōs ("love") with ágrōstis ("grass"), the source of the universal common name "lovegrass" (also "love-grasses" or "canegrass"); some authorities consider the etymology obscure. The genus was established by Nathanael Matthaeus von Wolf in 1776 in Genera Plantarum (page 23).
Species counts vary by source: the Flora of North America treatment estimates roughly 250 species worldwide, while the Global Biodiversity Information Facility records 609 descendant taxa under the genus when subspecific names and synonyms are included. Members are found on every inhabited continent and across many islands, from tropical lowlands to temperate steppe and desert margins, with strong representation in Africa, the Americas and Australia.
Plants are annual or perennial grasses with highly variable growth forms, ranging from low tufts only a couple of centimetres tall to robust bunchgrasses reaching about 160 cm. Culms may be erect or geniculate. The diagnostic spikelets are two- to many-flowered and slightly to strongly flattened laterally, with characteristic lemmas and paleas; in most North American species the anthers are very small (about 0.5 mm or less). Seeds are dispersed by sticking to animal fur and clothing, by wind, or simply by gravity.
Several lovegrasses are economically and culturally significant. Eragrostis tef (teff) is the staple cereal of Ethiopia and Eritrea, where it supplies an estimated two-thirds of daily protein intake and is the foundation of injera, a fermented sourdough flatbread; Ethiopia produces more than 90% of the world's teff, and the grain is increasingly traded internationally as a gluten-free crop. E. curvula (weeping lovegrass) is planted widely for soil-erosion control, E. amabilis is grown as an ornamental, and several species — including E. clelandii in Australia and E. tremla in Chad — have been documented as famine foods. The genus also supports wildlife: lovegrasses are larval hosts for the Zabulon skipper butterfly and provide cover for ground-nesting birds such as Botteri's sparrow.
Etymology
The genus name Eragrostis is generally explained as a combination of the Greek érōs ("love") and ágrōstis ("grass"), giving rise to the universal common name "lovegrass". Some flora treatments, however, describe the etymology as obscure rather than transparent, so the love-grass reading is best treated as the traditional rather than the certain derivation. The genus was formally erected by Nathanael Matthaeus von Wolf in Genera Plantarum (page 23) in 1776.
Distribution
Eragrostis is one of the most widespread grass genera in the world, occurring on every inhabited continent and across numerous islands. It is especially diverse in Africa, the Americas and Australia, and is well represented across temperate, subtropical and tropical regions. Regional floras illustrate that reach: more than 50 Eragrostis taxa are recorded for the Arizona–New Mexico portion of the south-western United States, and Switzerland alone documents about a dozen species (including E. cilianensis, E. curvula, E. minor, E. pilosa, E. tef and E. virescens), many of them naturalised introductions from warmer regions.
Ecology
Lovegrasses are predominantly C4 grasses adapted to warm climates, with the well-studied Eragrostis tef serving as a model: it is a self-pollinated tetraploid annual whose C4 photosynthesis confers strong drought tolerance. Across the genus, seeds disperse by attaching to animal fur and clothing, by wind, and by gravity, helping many species colonise disturbed ground rapidly. Lovegrasses also play a role in their wider communities: they are larval hosts for caterpillars of the Zabulon skipper (Lon zabulon) and provide nesting cover for grassland birds such as Botteri's sparrow.
Cultivation
Cultivated Eragrostis species fall into three broad camps. E. tef is grown as a cereal crop, overwhelmingly in Ethiopia and Eritrea but with expanding plantings elsewhere for its gluten-free grain. E. curvula (weeping lovegrass), native to southern Africa, has been planted extensively for soil-erosion control on disturbed slopes and roadbanks. A handful of species — most prominently E. amabilis — are grown as ornamental grasses for their fine, airy panicles. Many other lovegrasses appear in gardens and arboreta only incidentally as drought-tolerant naturalised volunteers.
Cultural uses
The standout cultural use is teff (E. tef), the staple grain of Ethiopia and Eritrea, ground into flour for injera, the fermented sourdough flatbread that defines regional cuisine; in Somalia closely related preparations underpin laxoox. Teff is estimated to supply about two-thirds of daily protein intake in Ethiopian diets. Beyond teff, several lovegrasses have served as famine foods — E. clelandii in Aboriginal Australia and E. tremla in Chad among them — and certain species are used in Hindu pūjā temple rituals.
History
The cultivation history of the genus is dominated by teff (E. tef), domesticated in the Ethiopian Highlands somewhere between roughly 4000 BCE and 1000 BCE, with genetic evidence pointing to E. pilosa as its wild ancestor. The genus itself was scientifically described much later, by Nathanael Matthaeus von Wolf in 1776.
Taxonomy notes
Eragrostis belongs to family Poaceae, subfamily Chloridoideae, where it is the type genus of tribe Eragrostideae (subtribe Eragrostidinae). The genus was published by Nathanael Matthaeus von Wolf in Genera Plantarum (page 23) in 1776 and remains accepted in current backbones such as GBIF, which lists 609 descendant taxa under the name; treatments focused on accepted species, such as the Flora of North America, place the count closer to 250. Diagnostic spikelet characters include 2- to many-flowered, slightly to strongly flattened spikelets with characteristic lemmas and paleas, and in most North American species anthers no longer than about 0.5 mm.
Phytoremediation potential
Beyond its food and forage roles, Eragrostis has unexpected biotechnology relevance: E. bahiensis has been documented as a hyperaccumulator of radiocaesium (¹³⁷Cs), giving it potential for phytoremediation of contaminated soils.
