*1: Sandy soil in
sheltered bulb-field, lying fallow, The Garrison, St Mary's,
Isles of Scilly, Mar. 1950, JLH & PJW (Castell 1952: 89,
Paton 1967a: 223, 1968c: 619, 1969a:
691).
*2: Sandy soil between
open turf, eastern car park Porth Cuney [sic = Luney] Cove,
Caerhays, SW9741, 2008 [sic = 3 Apr. 2002],
JAP, Paton 8100 (Blackstock 2009: 67); discovered here by SRE
in late March 2002.
Widespread in Isles of Scilly. First recorded from
mainland of vc1 in coastal car park at Marazion in 2005 (DAP
& CDP in Hill 2005: 44). Discovered in 2002 on a car-park
in vc2; otherwise known in British Isles only from single
record in Scotland.
Many records from Isles of Scilly and both mainland
records have been confirmed by microscopic study of spores,
although the species is only likely to be confused with Riccia cavernosa
(which differs in habitat, seasonal timing of growth and spore
maturation, and at least slightly in typical coloration of the
thalli).
Common to abundant in bulbfields in the Isles of
Scilly, with sparser records there extending along paths and
track edges, even onto paths on cliff tops and coastal heaths,
to which it appears to be distributed on footwear. Mainly
grows on partly bare, unshaded to lightly shaded, damp, loamy
soil but extends onto drier and wetter sites and persists when
shaded by crops and hedgerows. Associates often include Riccia sorocarpa, Sphaerocarpos
michelii, Sphaerocarpos texanus,
such low mosses as Bryum dichotomum, Bryum rubens, Kindbergia praelonga
and Tortula
truncata, and various low herbs and
grasses.
The only mainland records are from coastal car
parks, on sandy soil at Porthluney Cove (vc2, SW94Q) where
discovered in early 2002, and Marazion (vc1, SW53A) where
discovered in March 2005 (latter near to Crassula tillaea)
(Hill 2005: 44).
The thalli grow from autumn to spring; spores
common: mature 3, 4.
