*1: Hayle, 1842, WC
(OXF) (Paton 1969a: 693).
Although this species is named in honour of John
Ralfs, who was resident at Penzance for many years, his type
specimen came from Aberfraw in Wales (Marquand 1891: 237). The
authorship of this name has been revised to follow Stotler et al.
(2002).
Known for many years from the two main areas of
sand-dunes on the north coast of vc1, which still support
strong populations. Indeed, populations in the Upton Towans to
Godrevy region appear to have greatly increased since about
1995. It has not been refound in several other areas for which
there are old records.
At Gear Sands and Upton Towans mainly on damp
calcareous sand in hollows of fixed dunes and dune grassland,
including natural dune-slacks, hollows resulting from past
disturbance, hollows along paths and the floor of a disused
sand pit. Occurs on blown sand on cliff-top at Gwithian
Towans, including sandy sites over old mine-spoil. At Upton
Towans also locally growing over slag and spoil of
metalliferous mines at landward edge of dunes, growing in thin
soil or among lawns of acrocarpous mosses. One colony there
also in moss carpet a few cm thick growing over extensive
horizontal mortared-brickwork of ruin. All sites are unshaded
and have very short vegetation, mainly kept low by intense
rabbit grazing, often accompanied by trampling on pathways.
See Holyoak (1998, 1999, 2000) for detailed population studies
and lists of associated plants.
Antheridia seen: 10-12. Well-grown female bracts:
12. Capsules frequent ('late winter and early spring'):
immature 1-4.
Some of its sites near the landward
edge of Upton Towans and at Gwithian Towans are on pathways
that were surfaced with metalliferous mine-spoil during the
1939-45 war, with only a thin layer of compressed blown-sand
now covering the mine-spoil. In places it grows there with Hymenostylium
recurvirostrum, suggesting tolerance of Cu in the
substrate. Chemical analyses of its substrates show that it
can tolerate high levels not only of Cu, but also of Pb and
Zn, and indeed presence of all three of these metals at high
concentrations. All substrates investigated were
basic.
Analyses of substrates from localities inCornwall
(metal concentrations given as µg/g dry
weight):
LOCALITY (N samples) Cu
Pb
Zn
pH
Source
Upton Towans, vc1 (7)
251-4499
31-2242
354-15287
7.1-7.9
Rouen (2000)
