*1: Near Trelew,
Mylor Bridge, 1965, JAP
(BBSUK) (Paton 1969a: 733).
*2: Above Golden Mill,
Grampund, 1968, JAP (BBSUK) (Paton 1969a:
733).
First recorded from Britain by Watson
(1968), but identification presented difficulties until
Whitehouse (1973) described the rhizoidal tubers. P. lutescens is probably
commoner than records indicate, since it is a rather
inconspicuous moss that has only been recorded when tubers
were seen. Similar plants, often small and sparse, and lacking
tubers, which could not be identified with confidence (with
rather narrow leaves toothed above and leaf cells about 14 µm wide) were seen
from additional localities.
Grows as scattered plants, or forms very small
patches or tiny low lawns. Habitat notes from C&S are as
follows. Colonises partly bare soil, often with other low
mosses. Characteristically recorded from mildly acidic loamy
soil on horizontal to inclined free-draining surfaces, but it
also occurs on humic, silty and clayey soils, sometimes in
damp places. Most of its populations are slightly to rather
heavily shaded e.g. by deciduous trees or overhanging banks.
It is frequent on laneside banks and Cornish hedges, with
records also from stream banks, banks in woodlands, groves and
churchyards, soil among roots of a wind-thrown tree in
woodland clearing, low on a N.-facing sea-cliff, track edges
(both in the open and in woodland), a low bank near a china
clay quarry and a cattle-poached area in wet pasture. Atypical
records were from the edge of an arable field (cereal stubble,
but partly shaded by hedgerow) and on thin soil on bark of
felled saplings in a wood pile. Dicranella heteromalla
is the commonest associate; others recorded were Bryum bornholmense, Bryum sauteri, Dicranella staphylina,
Trichodon
cylindricus, Epipterygium tozeri,
Fissidens bryoides
var. bryoides, Fissidens celticus, Fossombronia wondraczekii, Mnium hornum, Pohlia melanodon, Pseudotaxiphyllum
elegans, Pseudephemerum
nitidum.
Rhizoidal tubers usually present, but often few in
number and often lacking from small plants. Perigonia seen: 6.
Not seen
c.fr.
