Chance hybrids Clive Stace

CLIVE STACE

In BSBI News 142 (2019) I illustrated a hybrid lupin (Tree Lupin × Russell Lupin) that appeared spontaneously in my garden, and suggested that it is better to make sure of the identity of ‘weed’ seedlings that appear before deciding that they are undesirable. I mentioned two other chance hybrids that had arisen in my garden, but at that time I had mislaid their photographs. Having now found them, I thought it worth drawing attention to more plants for members to look out for in their gardens.

The hybrid Digitalis purpurea × D. lutea, involving extremely different looking parents, is well known in horticulture and if you grow both species it is likely to arise sooner or later. There can scarcely be a more obvious intermediate hybrid. Although it is claimed that it resembles its female parent more closely, so exists as two morphs from reciprocal crosses, I could not say which parent my plant more closely resembled. It has been found in the wild on the Continent, but not as far as I know in Britain. It arose twice in my garden, with the same morphology each time, but in both cases died after flowering (hence closer to D. purpurea in this respect). Its hybrid name is D. × purpurascens Roth, and it has even had a book devoted to its study (Henslow, J.S. 1831. On the Examination of a Hybrid Digitalis).

Hybrids between Primrose, Cowslip and Oxlip are known in Britain in all three combinations, and there are a few reports of the triple hybrid (Primula × murbeckii Lindq.) from West Suffolk. For many years I grew a single plant of Oxlip in my garden, and about 15 years ago a plant arose very near it that obviously (from the corolla colour) had a garden polyanthus (P. veris × P. vulgaris) in its parentage. That the other parent was the Oxlip was clearly evident from the bicoloured calyx (darker green stripes on the five midribs), the diagnostic feature of Oxlip. The plant thrived and enlarged at least until I left the garden in 2013. It would be interesting to hear of members’ other serendipitous discoveries.

Left: a hybrid foxglove, Digitalis purpurea × D. lutea; top right: flowers of D. purpurea, the hybrid and D. lutea; bottom right: a 3-way Primula hybrid Primula × murbeckii.