Companions or near neighbours of the _Hottonia_ are the arrow-head, at once recognized by its bold sagittate leaves, and the frog-bit, another flower of three white petals, whose small reniform foliage, floating on the brooks, gives it the appearance of a dwarf water-lily. By no means common, but growing in profusion where it grows at all, the dainty little frog-bit, once met with, always remains a favourite. The true water-lilies, both the white and the yellow, are also native on the levels; so, too, is the quaint water-milfoil, with its much-cut submerged leaves resembling those of the featherfoil, and its numerous erect flower-spikes dotting the surface of the pools. All these water-nymphs may be seen simultaneously blossoming in June. More prominent than such small aquatics are the tall-growing kinds which lift their heads two or three feet above the waters. Of these quite the handsomest is the flowering rush (_butomus_), stately and pink-petaled; among the rest are the two water-plantains (the lesser one rather uncommon); the water-speedwell, a gross and bulky _veronica_ which lacks the charm of its smaller relative the brook-lime; and the queer mare's-tails, which in the midst of a running stream look like a number of tiny fir-trees out of their element. The umbelliferous family is also well represented. Wild celery is there; and the showy water-parsnip (_sium_); the graceful tubular water-dropwort, and its big neighbour the horse-bane, which in some places swells to an immense size in the centre of the ditches. On the margin grows the pretty trailing money-wort, or "creeping Jenny"; and with it, maybe, the white-blossomed brook-weed, or water-pimpernel, which at first sight has more likeness to the crucifers than to its real relatives the primroses, and is thus apt to puzzle those by whom it has not previously been encountered. Rambling beside these so-called brooks, which are mostly not brooks but channels of almost stagnant water, one cannot fail to remark the clannishness of many of the flowers: they grow in groups, monopolizing nearly the whole length of a ditch, and making a show by their united array of leaves or blossoms. In one part, perhaps, the slim water-violet predominates; then, as you turn a corner, a long vista of arrow-heads meets the eye, nothing but arrow-heads between bank and bank, their sharp, barbed foliage topping the surface in a phalanx: or again, you may come upon fifty yards of frog-bit, a multitude of small green bucklers that entirely hide the water; or a radiant colony of water-lilies, whose broad leaves make the intrusion of other aquatics scarcely possible, and provide a cool pavement for wagtail and moorhen to walk on. It is noticeable, too, that the lesser water-plantain, unlike the greater, is almost confined to one section of the levels; and in like manner the brook-weed and the burmarigold have each occupied for their headquarters the banks of a particular dike.