The winter iris, as it happens, is not particularly well known. It is not widely sold in garden centres because it does not present well on the sales bench, looking like an unruly bunch of dead grass.
It has a habit of flowering intermittently, taking its chances with a couple of flowers during occasional fine spells. This drip-drip of flowering is not doing anything for sales, but this is a very important part of the delight of a first flower and every other flower that follows. Who could resist a plant that flowers on and off from November to March?