Des Higgins writes

Equisetum telmateia can be 3 feet or more tall. In Ireland it is
widespread. You get it in damp banks (e.g. stream banks) and verges.
E.hyemale and E.variegatum are very decorative and you see them (or
something similar) cultivated in ponds. E.sylvaticum (the one K is
talking about) is found in woods (surprise surprise :-) but I do not
know it. E.arvense is the invasive weed. The rest are probably
harmless. Des

Equisetum sylvaticum differs from the more usual horsetail in that the
branches are themselves branched, so instead of the usual bottlebrush
effect, the overall look is very light and feathery. It's growing on a
steam bank in amongst rosebay willowherb.


--
Kay