Fig. 146. A small piece of the underground stem of Carex, with tufts of leaves coming above the level of the sand; (s) stem, (r) roots (cut off) with small side roots, (sc.) scale leaves underground.
Sometimes the stem can grow up and up, even though it is continually buried by the shifting sand, as you can see very well in the case of the sea holly. You may dig for more than a dozen feet before you come to the end of the vertical stem of what seemed to be quite a small plant (see fig. 147).
Fig. 147. Sea Holly, showing the plant at the surface, and the long stem below the level of the sand (s).
Along the shore are other plants of quite a different kind, which have also special characters to help them to conquer a region which seems to be very inaccessible to land plants. Many curious plants live in the mud-flats that are frequently covered by the tides, and which can therefore only get salt water. You remember that salt kills ordinary land-plants, so that these must be specially built to be able to stand it. Most of them have very thick, fleshy leaves, and rather bushy stems, while others have leathery leaves covered with a kind of wax, or with hairs, which make them look grey. Look at the sea-daisy, and you will see that the leaves are very thick and juicy; so are those of the sea-blite and salt spurry. The boldest of all these plants, the marsh samphire, which goes furthest out to sea, and may grow on bare mud covered by every tide, has not leaves at all, but very thick, fleshy stems, which are green and do the work of leaves (see fig. 148).
