A grass-like habit is assumed by some plants. This character is attained in the meadow vetchling by the arrested development of the compound leaves and the great elongation of the stipules. Lathyrus nissolia has the stipules minute, but the phyllodes or leaf-like petioles impart the grass-like character. A moss-like habit occurs in a great many plants belonging to very different families; thus the wiry stem of the purging flax reminds one of the seta of Polytrichum. The pearlwort of the walls, many alpine saxifrages, pinks, and gentians present very much the appearance of mosses, _e. g._, Silene acaulis, Saxifraga bryoides, S. hypnoides, Arenaria Cherleri, etc. The sub-species Saxifraga geum is another instance of leaf analogy. The generic name Pyrola implies a fancied resemblance of the leaves to those of the pear tree. Certain leaf-types frequently recur, the rough broadly tongue-shaped leaf of the bugloss, for example; hence the very common specific appellation echioides. The nettle-leaved bell-flower reproduces the foliage of Urtica and the sinuate leaf of the oak appears in several families. Parasitic phanerogams like Rafflesia commonly exhibit the fungoid character in a marked degree. In their internal structure, coloring, spore-like seeds and other characters they approximate closely to the fungi. As examples of homomorphism between closely allied plants may be mentioned the false oat, which so strikingly resembles the cultivated species, and the barren strawberry, which agrees so closely with the cultivated strawberry of our gardens.