Oxalis corniculata var.
atropurpurea Planch., a Procumbent Yellow-sorrel

Introduction, neophyte, invasive garden escape, so far very rare.

July 1993; McNeill, I.; roadside waste ground, Ballycassidy.

A rather insignificant-looking, short-lived perennial, often selfing and behaving as a small ruderal annual, this species can regularly produce more than one generation in a season (Young 1958). Despite the minor scale of the plant, the contrast between the clusters of little yellow flowers and, in this variety, the bronze-brown trifoliate leaves, makes some folk regard it as a desirable garden subject, although perhaps it is most suitable for troughs and other entirely confined, miniature gardens. While it usually remains a garden, greenhouse and conservatory weed, frequently infesting bare soil around the base of plants in pots, as listed above O. corniculata var. atropurpurea has escaped into the wild in Fermanagh at least once. RHN and the current author (RSF) suspect that the species was transported and dumped among garden waste in roadside waste ground. Fly-tipping of this nature is unfortunately an all too common practice in Fermanagh.

The New Flora of the BI (1997) describes this species as being a pernicious weed of gardens, paths, walls and waste ground, which has it just right! Although the short, wiry procumbent stems root at their nodes, by far the most effective means of spread is by the copiously produced, lightweight seed, apart that is from deliberate human transport in the back of a vehicle to a quiet, concealed, rural spot, where garden waste is all too often deposited.