Botanical Discoveries No.4 (2002) Bob Ellis
In late May, we held the first of two courses on grasses,
sedges and rushes with Arthur Copping. A couple of species new to my
list were noted on Smee Loke - namely hairy sedge Carex hirta
and spreading meadow-grass Poa humilis.
Later in the year, David reported a plant by the path beside Crake's
dyke, near the river. This turned out to be greater lettuce Lactuca
virosa, which seems to be spreading throughout the county, as does
its close relative the prickly lettuce Lactuca serriola. The
two are best distinguished when in seed, as the achenes (fruits) of
the greater lettuce are a purplish black colour whereas those of the
prickly lettuce are dull brown.
Towards the end of August, I spotted for the first time at Wheatfen
a few thalli of greater duckweed Spirodela polyrhiza in the dyke
between Crake's Marsh and Thack Marsh. We have five species of duckweed
at Wheatfen, including least duckweed Lemna minuta, which is
a recent introduction from America. The relative abundance of the different
species seems to vary from year to year.
I sometimes wonder what goes on behind the wood shed! Last year I mentioned
the discovery of bulbous rush there and this year several small plants
of hard fern Blechnum spicant have appeared. This attractive
fern is rather scarce in Norfolk, only occurring in some two-dozen or
so localities. It is far more frequent in the north and west of Britain.
Did spores arrive as strays on the wind or did they travel here from
Wales on Martin Ellis's Wellington boots, finding a suitable place in
which to germinate while he was chopping wood for the fire?
How are some of the plants that I have mentioned in previous reports
getting on? This year there were five spikes of the broad-leaved helleborine
Epipactis helleborine on the edge of the wood and several managed
to flower and set seed. The bulbous rush Juncus bulbosus is still
doing well at both locations in the wood - but no new colonies have
been found... yet. The slender rush Juncus tenuis was well and
truly crushed and mangled during the dredging of Sluice Dyke but several
young plants were found further along the path - so the process has
probably helped to spread the species.
The little sedge in the clearing at the south of Surlingham Wood turned
out to be common yellow-sedge Carex viridula subspecies oedocarpa
and a few new clumps have been found in the vicinity. The fibrous tussock-sedge
Carex appropinquata is doing fine on Thack Marsh although it's
hard work finding it as the surrounding vegetation is now very lush.
Another colony of green figwort Scrophularia umbrosa was found
in 2001 on the edge of Home Marsh and the original colonies beside Crake's
Marsh are still thriving. I was interested to note that Ted mentioned
it growing on the banks of the river at Surlingham in 1964 where he
gave it the vernacular name 'western figwort'. The fool's water-cress
Apium nodiflorum has spread like wildfire in Boundary Dyke, Alder
Carr Dyke and the dyke between Crake's Marsh and Thack Marsh. It has
also cropped up in several other dykes. In 2001, there was still a small
patch of frog-bit Hydrocharis morsus-ranae in Middle Marsh Dyke.
This summer several large patches were seen and I suspect it will soon
appear elsewhere on the reserve.
No report of botanical discoveries would be complete without mentioning
some obscure little moss - and this year is no exception. I was pleased
to find a few plants of the green-tufted stubble-moss Weissia controversa
on the soil around the upturned roots of a fallen tree in Wood Carr.
The only other report of this moss at Wheatfen was in 1934 when it was
identified by Reverend Rhodes, but then it is very small and easily
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