Slender Trefoil is listed in the East Riding of Yorkshire Rare Plants Register as being recorded in only five places, including at Ivy House in 2012. It was found growing in a crack in the concrete near the tool shed door but succumbed to a dose of weed killer later that year, and was not seen again until June 5th 2017, this time in relative safety on the car park.
This very tiny plant may be more widespread than has been historically recorded. Not many people look for wild flowers so small and if they do, may easily mis-record their finding as Small Trefoil. The distinction between the two depends largely on microscopic features, the most distinctive being the scattering of red dots on the surface of Slender Trefoil leaves. For anyone wishing to look this up in their books the scientific name is Trifolium micranthum.
The photograph shows the size of the plant and flowers relative to a match head. The pea-flower like flowers are just emerging from their white calyces and as an idea of size of individual flowers, the ‘flower’ nearest the match head is a cluster of three!