Symphytum × ferrariense (S. officinale × S. orientale, Boraginaceae) in Cambridgeshire, Cheshire and Norfolk: first records for England

Abstract

Three populations of Symphytum × ferrariense C.Massal., the hybrid between S. officinale L. and S. orientale L. are described, in Cheshire, Cambridgeshire and Norfolk, all involving a cream flowered form of S. officinale. This is the first time S. × ferrariense has been reported in England, and the first time it has been found in the wild outside the coastal department of Var in southern France, where it has not been seen since 1892. All the late 19th century occurrences were close to the port of Toulon and it is suggested that they were escapes or relics from horticulture, having been inadvertently imported along with S. officinale for herbal purposes, probably from the Black Sea coast of Russia. The three populations described here, however, seem to be the result of hybridisation in the wild, which is likely to occur more often now that S. orientale is spreading from its original urban sites into rural areas close to the wetland habitats favoured by S. officinale. The Cambridgeshire population consists of two very different forms, one probably an F1 hybrid and the other the result of backcrossing of this F1 plant with the presumed pollen parent population of S. officinale nearby; the Cheshire and Norfolk populations are also quite distinct. All four forms show good intermediacy between S. officinale and S. orientale, but differ in habit, upper stem leaf shape and leaf and stem indumentum; they are given separate descriptions, but with a combined description in the Conclusion section. All four resemble a cream flowered form of S. officinale, but a quick check for the half-dissected calyx and shorter stem winging should suggest Symphytum × ferrariense rather than pure S. officinale; another helpful spotting feature is that the open flowers are pure white or greenish yellow, rather than cream in colour. Material from the Cambridgeshire population has been deposited in CGE.