Not a great deal is known about the Tall Sea Pen, Funiculina quadrangularis, as it is only found in a small number of locations. It needs a muddy sea bed in still water over twenty metres deep where there is no disturbance from tide or swell. It therefore thrives in sea lochs that reach deep inland. It appears to be colonial because it is usually found together in large numbers.
Growing to two metres high, some are found "lying down" instead of erect but I am unsure whether these animals resume their erect position at some stage. Related to anemones, they are passive suspension feeders, extracting plankton and organic material from the surrounding water.