Western Gorse or “normal” Gorse?

by Gill Smith

Last year we found what we thought was western gorse, Ulex gallii, growing on Rudland Moor. However, I was never confident about separating the two species. This autumn (October 2006) I spent a few days in Ireland, where there were two quite distinct gorses growing together. Although it was hard to define exactly what the differences were they had quite a different jizz, which I will try and summarise.

First of course was the obvious fact that one kind (U. gallii) was flowering profusely, whereas the other had ripe, black seedpods and tiny flower-buds. (U. europaeus).

Second, the flowering one was a slightly yellowish green overall, whereas the non-flowering one had a distinctly blue cast.

Third, the flowering one had masses of small subsidiary spinelets obscuring the twigs, but in U. europaeus the (grooved) twigs could be seen between separate whorls of spines. This distinction was not absolute, but there was certainly a strong tendency for the presumed U. gallii bushes to have the “fuzzy” effect.

Fourth, the bushes of U. gallii were in general smaller, with slightly less daunting spines, and occurring as single bushes – or at most in small groups, never forming extensive, tall thickets as U. europaeus does.

western gorse Ulex gallii
Western Gorse (U. gallii) showing the green spines, hidden twig and autumn flowers.

common gorse Ulex europaeus
Common Gorse (U. europaeus) showing the bluish spines, visible twig and no open flowers.

I could not see any difference in the colour of the flowers (there were a few open flowers on some of the “blue” bushes), and I did not find much difference in the small bracteoles at the base of the calyx, mainly because they are so tiny. It is true that there was almost no scent from the flowers, but on a damp Irish day in October I’m not sure even the normal gorse would have had its usual coconut-like smell. Apparently it is also possible to separate the species by the calyx (that of U. europaeus having more spreading, “furry” hairs and being only about half the length of the corolla) , but again I have to say this was not apparent in the field.

[Later] Further examination of a bush flowering in early November back in Yorkshire, which I determined as U. europaeus, suggests that the scent is indeed present, even in late autumn on a cold day. Also the jizz is of bigger flowers, with a larger and more upright standard, so the flowers look altogether more “open”. This particular bush also had noticeably bigger (well, less minute) bracts that I could actually see without a lens!