[Hardy-l] Moss on the roof

[Patrick Roper]

Subscribers will be pleased to hear that a recent paper has been published
on thatch moss (Leptodontium gemmascens) that occurs, among other places, on
the roof of Thomas Hardy's cottage in Dorset.

Leptodontium gemmascens (Mitt.) Braithw., commonly known as thatch moss
because of its predilection for thatched roofs, is a unique moss in the
British flora.  It has a distinctive appearance, with gemmae clustered on
the ends of its leaves, but it lacks sexual reproductive structures.  Rare
in Britain, it is scattered through western Europe and has isolated stations
in the Southern Indian Ocean.  It is closely associated with habitation, and
in common with other members of its genus, grows on decaying vegetation.

Thatch moss has been known on Hardy's Cottage since 1994 and "judging from
its abundance, present for some time before that", so it may have been
something TH had seen.  It mostly occurs "on the gable ends and eaves of
roofs, or in the valleys or chimney abutments where rain runoff maintains
higher moisture levels in the coat for longer periods."

There is a good colour photo of Hardy's Cottage in the paper showing an
impressively green and mossy roof.

Subscribers will be relieved to hear that conservation of thatch moss is
being taken very seriously by the National Trust who own the cottage.  In
2006 the NT became joint Lead Partners under the UK Biodiversity Action
Programme with Natural England to ensure that thatch moss is taken into
account when buildings need to be repaired and the NT, in consultation with
Master Thatchers and English Nature (now Natural England), has produced
guidelines for the management of thatched properties aimed at the
conservation of L. gemmascens.  As St David said "look after the little
things in life".

I am sure Thomas Hardy would have been much cheered by all this.  He may
even have unwittingly been suggesting a habitat for thatch moss when he
wrote in the Mayor of Casterbridge "But nothing was visible there save the
ricks, and the humpbacked barn cushioned with moss."

The full reference for the article is: Porley, Ron (2008) Threatened
bryophytes: Leptodontium gemmascens.  Field Bryology (the Bulletin of the
British Bryological Society), No. 96, October 2008: 14-24.

There is a picture and further information on thatch moss here:

http://hosting.sleath.co.uk/bbs/accounts/mosses/Leptodontium%20gemmascens_MP
T.pdf


Patrick Roper