Wednesday 11 May 2011

Wild Service-tree

The leaf of the Wild Service-tree is a very characteristic shape

RFS President Anthony Bosanquet
presents Sir Henry Elwes with a young tree
Colesbourne was honoured yesterday by a visit from about 100 members of the Royal Forestry Society, which is holding its annual Whole Society Meeting in Gloucestershire this week, visiting sites of forestry and dendrological interest. While they were here a presentation was made to Sir Henry Elwes of a young Wild Service-tree, Torminaria torminalis, of Gloucestershire origin.

There are in fact already two Wild Service-trees here, an unfortunately shaped youngster, and a large old one in the Ring Meadow. This is in heavy flower this year, a phenomenon I had not seen before, and the tree looks rather good as a consequence. I was told today that the wild trees in the Forest of Dean are also flowering heavily this year, possibly as a result of fungal stress last year. It will be good to have another specimen nearby to replace it in due course.

Old specimen of Torminaria torminalis
Wild Service-tree is a particularly interesting species. It's native to England and Wales, but is never common, and is usually found in ancient woodland or old hedgerows. In many places its regeneration is very poor, perhaps because it needs open sites for germination and establishment, but it is also said that the seed has very low viability. The trees are self-incompatible and need a pollinator to set fruit - a good reason to have another tree here.  The species has a long and interesting history, with the fruits having once been used to make a drink called checkers or chequers, while its botanical name is derived from the use of the fruit to cure colic, tormina in Latin. The odd word service is an anglicized corruption of Sorbus, and was first applied to the (just about) edible fruits of Cormus domestica (Sorbus  domestica), the Service-tree. A very pleasant and interesting account of the species is to be found in a little book by Patrick Roper, Chequer, published by Sage Press, though my copy has gone astray, alas.

The species is generally known as Sorbus torminalis, but there are good grounds (both morphological and genetic) for confining that generic name to the pinnate-leaved rowans, and excluding all the other genera generally stuffed into a rag-bag known as Sorbus. Thus the whitebeams become Aria, the Service-tree becomes Cormus domestica, and the Wild Service-tree is Torminaria torminalis. The problem with this is that the various genera hybridize with varying degrees of ease, and so the easy way round the problem is to call them all Sorbus, but as Rosaceae is well-known to have poor breeding barriers and hybrids occur between widely distinct genera are known, this seems to me to be intellectually lazy. A useful but fairly heavy paper on the subject is available here.

Wild Service-tree is a useful ornamental, not growing too fast or too large into a shapely tree, and the flowers and fruits are decorative when they occur. Its leaves are almost unique in shape, and can hardly be confused with those of anything else. They turn to attractively dusky oranges, reds and browns in autumn.

The old tree at Colesbourne Park is flowering prolifically this year

Flowers of the Wild Service-tree

1 comment:

  1. Thanks for the reference for the phylogeny. I always find them fascinating, and I don't know about other gardeners but I always think the systematics makes gardening more interesting rather than less.
    I made some related notes on Chamaemespilus here if anyone's interested.


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