Meadow yellow

Meadow yellow
Bulbous Buttercup (Ranunculus bulbosus) in a Devon meadow

Thursday, 16 June 2011

Robin’s pincushion

A tip-off earlier this week had me stumbling around a local meadow hunting for an elusive Bee Orchid (Ophrys apifera). This is a difficult botanical time of the year for hayfever sufferers. A warm June evening with a slight breeze is perfect for wind pollinated grasses to exude their zillions of sneeze-inducing dust granules. So with sandpapered eyes, streaming nose and rapidly numbing brain I wandered through thigh high Cock’s-foot, Sweet Vernal and False Oat grasses. No orchid for my pains, but I was attracted to a red tufty moss-like ball attached to a rose sapling. A dim memory flickered about parasitic growth but no more ID knowledge was forthcoming. Further on I came across many more of these and was struck by their weirdness. A few days later I was back in the meadow with an accomplice on the Bee Orchid trail, Mary, who was very quick to identify the rose associated curiosity as a Robin’s pincushion.

Its other name is Rose Bedeguar gall and the cause of this splendid manifestation, as stunning as any rose flower, is a gall wasp Diplolepsis rosae usually found on wild dog roses like in this case. It is actually fairly common and I have seen it before but without knowing that it was indeed a gall. In addition to the gall wasp there could be up to 14 different insect parasitoid species that live within the gall making up a broader community (Randolph, 2005). The gall has inevitably attracted interest over the ages, such as its use in medieval medicine for restricting blood flow and as a remedy to help sleep if placed under a pillow. Pity it has no use for hayfever sufferers. It is remarkable how nature has evolved to allow an insect to dupe a plant to alter its growth to create such a bizarre home. In contrast the Bee Orchid has turned the tables on the insect world, duping the bee into trying to copulate with its flowers and in doing so aiding the reproduction of the plant.

..and if you’re interested, I did find the Bee Orchid with a little help!

Randolph, S. (2005) The natural history of the Rose Bedeguar gall and its insect community. Sudbury: British Plant Gall Society.

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