Bupleurum tenuissimum (Slender Hare`s-ear)

Bupleurum tenuissimum L.

Slender hare's-ear

Status: scarce

This is a plant of dry, usually brackish, grassland on sea-walls, drained grazing marshes and, less frequently, on the upper (often disturbed) parts of saltmarshes. It typically occurs in short turf with plenty of bare ground, and can be locally abundant in disturbed areas, for example alongside trackways, ditches and spoil dumps, and in areas subject to poaching by livestock.

Associated species are varied, and include several other nationally scarce plants with similar habitat requirements and geographical distribution, e.g. Hordeum marinum, Parapholis incurva and Trifolium squamosum. The only recent inland records are from Worcestershire, where it still occurs on several commons. It is confined to the lowlands.

B. tenuissimum is an annual, flowering from July to September. Seed germinates in autumn and spring, and the fact that plants normally grow in open situations suggests that bare ground is important for germination and successful seedling establishment. As with many annual species, population size can vary considerably from year to year. However, it is uncertain whether it develops a persistent ‘bank’ of buried seed.

B. tenuissimum has disappeared from almost all its inland stations. On the coast, too, there have been some losses, particularly towards the northern edge of its range. Many B. tenuissimum populations are closely associated with sea-walls, and these are likely to be at risk from engineering schemes to upgrade coastal defences.

It is found on the coasts of western Europe northwards to southern Scandinavia (Denmark and Sweden), also locally inland. In southern Europe it occurs by the Mediterranean and from there eastwards to the Middle East. 

S. J. Leach