This is a very pretty sea-weed, which you may often find growing in great quantities in the pools which are left among the rocks as the tide goes down. When its long, narrow fronds are waving to and fro in the water it really looks most lovely, and you can almost fancy that you are gazing down into fairyland. And as the shrimps and prawns and little fishes dart in and out among its bright green leaves, one might almost imagine them to be the fairies!
The fronds of this pretty sea-weed vary a good deal in width, for sometimes they are like strips of narrow ribbon, and sometimes they are scarcely broader than hairs.
In one way this is the most curious of all the plants which you may find on the shore. For it is not really a sea-weed at all, but is a flowering plant which somehow or other has taken to living at the bottom of the sea. You may often find it in the deeper pools just above low-water mark; and you can tell it at once by its very long, very narrow, bright green leaves. These leaves are often three or four feet in length, while they are only about three-eighths of an inch wide; so that really they do look very much like blades of grass.
The grass wrack is not one of the true grasses, however, for it has real flowers, which grow in a kind of sheath formed by one of the shorter leaves. And its stem creeps along under the muddy sand, and throws up leaves at intervals, very much like that of the common bracken. On many parts of the coast it grows in the greatest abundance. There are large fields of it, so to speak, below low-water mark, which afford refuge for all kinds of small sea-creatures. Indeed, if you want to catch these animals for yourself, the very best way to do it is to wait until the tide is quite low, and then to wade into the water and fish about in the masses of grass wrack with a small net.