by Dr M Lueth ©.
*1: Near Ruan Minor, 1909, AW (GL) (Paton 1969a:
748). This record is older than that listed as new for vc1 by
Warburg (1962: 376).
*2: Whitehay Moor, Withiel, no date [= late 19C], RVT
sendtneri is distinct from D. aduncus mainly in
having groups of alar cells that are relatively small and
separated from the costa by a relatively large area of
undifferentiated basal lamina cells, the alar cells extending
40-60% of distance to leaf middle at insertion, whereas the
enlarged alar cells reach ± to the costa in D. aduncus (Hedenäs
1998: 84, 98, 2003). Several other characters given for D. sendtneri by Smith
(1978: 561, 563; 2004) do not provide reliable distinctions
from those species.
It was realised in 2001-2005 that records of this
species from dune-slacks along the north coast of Cornwall
were based on misidentification of forms of D. aduncus with a strong
costa, apparently including all records from the Towans
(SW53U, SW54V, SW54W) and most of those from the Gear
Sands-Penhale Sands areas (SW75S, SW75T, SW75Y; some of those
still mapped here may also prove to be incorrect if voucher
specimens can be located and checked). The errors arose
because the standard flora (Smith 1978, 2004) gave inaccurate
descriptions and figures of the alar cells of D. sendtneri and also
relied on width of costa and other unreliable characters to
separate this species from D. aduncus.
Redetermination was based on the more reliable characters
given by Hedenäs (2003).
Near Hayle Kimbro Pool (Lizard pen.) it grows
submerged in and emergent from shallow water (<10 cm) of
pool, in short fen vegetation of area that dries in most
summers, and on damp ground at base of open cover of herbs in
dried-up edge of large pool. Associated with Agrostis stolonifera,
cuspidata, Eleocharis multicaulis
vulgaris (plentiful), Eleogiton fluitans, Ranunculus
Not seen c.fr. by DTH. Specimen from Newlyn East,
20 June 1964 (JAP 1952, E, conf. DTH) has
capsules fresh but already dehisced (not mentioned in Paton