Trifolium incarnatum L. belongs to the section Trifolium, and is a secondary wild relative of the cultivated crops crimson clover (T. incarnatum L.) and red clover (Trifolium pratense L.) (USDA, ARS, National Genetic Resources Program 2010). Two subspecies are native to Europe: Trifolium incarnatum ssp. incarnatum and Trifolium incarnatum ssp. molinerii (Balb. ex Hornem.) Ser. in DC. (Zohary and Heller 1984).

European regional assessment: Least Concern (LC)

EU 27 regional assessment: Least Concern (LC)

Trifolium incarnatum is a common species with a widespread distribution and with no major threats, therefore it is classified as Least Concern.

T. incarnatum is native to much of southern Europe, as well as the UK and Turkey. It is naturalized and widely cultivated in many temperate regions (USDA, ARS, National Genetic Resources Program 2010). In France it is widespread, occurring in the majority of departments; however, it is not recorded in 12 departments in the northern half of the country or the department of Lot in the south (Association Tela Botanica 2000–2010).

In the UK Trifolium incarnatum ssp. molinerii is recorded as native in only three localities on the Lizard peninsula in west Cornwall and Jersey (Preston et al. 2002). It is also present in six more localities along the south coast of England and one locality in East Anglia but these are all recorded as alien (Preston et al. 2002). In Spain, most of the locations are naturalized; the populations in Huesca are the only ones that are native (Muñoz Rodríguez et al. 2000).

The exact population size is unknown, but the species is common across Europe from Britain to Turkey. It is found in a variety of habitats and populations are stable.

T. incarnatum grows in fields, meadows, pastures and roadsides (Zohary and Heller 1984). It is an annual species, flowering between May and August. It favours sandy and clay soils, and is tolerant of an average annual precipitation of 920 mm, temperatures between 5.9ºC and 21.3ºC, and soil pH ranging from 4.8 to 8.2 (Duke 1981).

In the UK Trifolium incarnatum ssp. molinerii is a lowland species which is strictly maritime as it only grows within 200 m of the sea (Preston et al. 2002). It prefers open habitats such as cliff-slopes that are severely droughted in the summer (Preston et al. 2002).

There appears to be no major threats and this species is found in several habitats which are not threatened within its range.

Wild forms of T. incarnatum are potential gene donors for cultivated types, which are currently used as pasture and hay crops, as well as for making green manure and improving soil (Duke 1981). It is also a potential gene donor to the cultivated crops crimson clover (T. incarnatum L.) and red clover (Trifolium pratense L.) (USDA, ARS, National Genetic Resources Program 2010). Natural wild populations are grazed by wild and domesticated animal species.

T. incarnatum  is specifically listed in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture as part of the forage legume gene pool so warrants specific conservation attention.

Ex situ seed samples are available in numerous gene banks with the largest collections being held by the Trifolium Genetic Resource Centre in Perth, Australia (81 accessions), and the National Plant Germplasm System in Washington, USA (34 accessions) N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry Russian Federation, Aegean Agricultural Research Institiute (Menemen, Turkey), ICARDA (Aleppo, Syria) and University of Aberystwyth (Aberystwyth , UK) gene banks (Lamont et al. 2001).

EURISCO reports 126 germplasm accessions held in European genebanks, 11 of which are reported to be of wild or weedy origin. Of the wild accessions, nine originate from within Europe. These nine wild accessions originate from Bulgaria (one), Italy (two), Macedonia FYR (two), Spain (3) and Ukraine (one) (EURISCO Catalogue 2010).

In situ the species is likely to be passively conserved in many existing protected areas in throughout its range but as its conservation in these sites is not actively monitored it may be subject to population loss over time from factors such as climate change.