Saw them in Wisely (which helps narrow it down, doesn't it??!). They were in free standing dense clumps, possibly about a foot or so across at the base, the grass stood maybe 4 or 5 foot tall, the fronds were a browny bronze and I think the stems were either green or wheat coloured.
Their chief feature was that they grew dead upright, no 'cascade' effect at all.
Anyone know it?
TIA