Ranunculus auricomus, known as goldilocks buttercup[1] or Greenland buttercup, is a perennial species of buttercup native to Eurasia. It is a calcicole typically found in moist woods and at the margins of woods. It is apomictic, and several hundred agamospecies have been recognised.[1]
Ranunculus auricomus is a short and slightly hairy perennial herb with bright yellow flowers.[2] [3] It can reach a height between 30–50cm (20inches), and have as many as 10 palmately-lobed basal leaves. Its upper stem leaves are deeply divided into 3-5 narrow segments giving the plant a filiform appearance.[1] Its flowers are frequently imperfect or missing, making it difficult to identify Ranunculus auricomus by flowers alone.
Ranunculus auricomus is native to northern Europe and western Asia, approximately from latitudes 43 to 71 degrees and from western Ireland to the Ural Mountains.[4] In Britain it is generally a lowland species but has been recorded at 1090m (3,580feet) on Aonach Beag. It is common in England and southern Scotland but becomes increasingly uncommon in the north and west,[3] so much so that, for example, it is named in the description of the Nature Reserve of Coed Garnllwyd in the Vale of Glamorgan.[5]
Ranunculus auricomus is a perennial herb which is characteristic of deciduous woodland growing over base rich soils such as those underlain by chalk or limestone. In addition it has been recorded growing among scrub, along roadsides and in churchyards, and infrequently on open moorland in locations which are sheltered by boulders and on sheltered mountain ledges.[6] Flowering starts in April and peaks at the end of May and start of June, although these flowers attract pollinating insects the plant is incapable of being pollinated and reproduces by apomixis, the seeds developing from unfertilised ova.[2]
It has been hypothesized that since asexual reproduction in plants is associated with a lack of genetic recombinational variation in populations, this reduces the efficiency of selection against deleterious mutations.[7] This deficiency is considered to lead to the accumulation of mutations, a gradual increase in mutational load (Muller’s ratchet), and thus the rapid extinction of such asexual lineages. However apomictic, asexual R. auricomus appears to have overcome this limitation by having a little bit of sex.[7]
Ranunculus auricomus is a species aggregation in which several hundred agamospecies, that is species which lack gametes, have been found with possibly a hundred or so in Britain alone.[8]
