2004 Wheatfen Early Stagers 31st July One Day Meeting
Wheatfen is the ideal place for an introduction to fen vegetation. A plant has everything it could desire in this fen if it likes the calcareous environment. There is abundant water, nutrient, little pollution and humidity levels are high particularly in summer. As a consequence the plants can burgeon and flourish. Most plants encountered at Wheatfen are much taller and more robust than their counterparts elsewhere. Planned as an Early Stager, there were lessons here for all, since emphasis was placed on the differences between species examined and those they could be confused with.
Sonchus palustris (marsh sow-thistle) was found and grows up to 4 metres tall. Quite rare in Britain outside East Anglia, it prefers damp peaty or silted soils, which are rich in nitrogen. Being tolerant of saline conditions, it flourishes at Wheatfen. Apart from sheer size it can be distinguished from other Sow-thistles by its perennial, thick, erect, underground, root-like, organ and the pointed auricles on stem leaves. Carex paniculata (greater tussock-sedge) was another find and forms very dense tussocks that can get up to 1.5 metres high. With a terminal spike, it has two stigmas. The rough, plano-convex utricles, winged at the apex are enough to decide. It loves Wheatfen's base-rich soils and the seasonal change of water levels and is an importantcomponent of the hydrosere in that it eases the way for trees to become established. In East Anglia it has a rarer cousin Carex appropinquata (fibrous tussock-sedge) which occurs infrequently atWheatfen with one specimen seen. This seems to require less water movement and prefers a slightly more acid soil.
There are three tall waterside grasses common in Britain and in Wheatfen; Phragmites australis (common reed) is Britain's tallest native grass, it can top 3.5 metres and is used for thatching or for ornament when dried. It is a stout, coarse perennial, standing as canes throughout the winter. Its leaves are greyish, smooth- edged to 5 cm wide and look out for the "devil's bite" a third of the way along. The ligule is a line of hairs and the inflorescence is a spreading panicle of usually dark purple spikelets, flowering from August to October. It forms extensive beds by means of a creeping rootstock. Another tall, stout, creeping perennial Phalaris arundinacea (reed canary-grass) grows to 2 metres. A useful grazing or hay grass when young, it yields a large amount of juicy grass over a long period. Thirdly Glyceria maxima (reed sweet-grass), up to 2 metres tall, this is another stout, patch-forming perennial. A nutritious fodder grass, it is readily eaten by cattle.
Eupatorium cannabinum (hemp agrimony) and Filipendula ulmaria(meadowsweet) are well-known herbs of damp places, getting up almost as high as the ragwort. Peucedanum palustre (milk parsley) grew taller still. It is a practically hairless umbellifer and its feathery, 2-4 pinnate leaves form the main diet of Swallowtail butterfly caterpillars. We saw many of them on the first plant shown and looked for our own on others as we passed. Lathyrus palustris (marsh pea) was a nice find and much fun was had discerning differences among the Figwort clan. The degree to which the wings of Scrophularia auriculata and umbrosa (water and green figwort) were broader or not, whether staminodes were orbicular or divergent and the shapes of leaves caused much discussion. This proved the most awkward to resolve of the keys we studied. The day ended with a nice show of Telekia speciosa (yellow oxeye).
Hopefully this gives a flavour of all the plants introduced (far too many to mention) and how enjoyable and instructive the early stager series is.
Unsigned