The cliff-top landscape is irregular, tilting up and down, dipping back as a rule toward the west but in varied planes. Just above the beach its hollows are scoured out by the wind, almost denuded of vegetation, deep cups with drops below them sheer down to the beach. I have seen the remnants of house foundations in such hollows, or a creosoted pole or two sticking up above the surface of the sand, not too old by the look of them, proving what an ephemeral habitation such a place can be. Where the low growth holds on, sometimes in masses, like bearberry, or in patches like the Hudsonia, it too lacks a certain finality, giving a free, waving look to the surface of things. On the other hand this vegetation is definite enough. There is no fragility to it. It is scraggy and tough. The strong shrubby growth may be held down but it also gives the landscape a symmetry and economy; it does not give the impression of being hit or miss at all but very definite and sure of its place, as sure as wind-struck, salt-sprayed plants can be. Each plant stays rooted from place to place through this sandy earth, being adapted to intense light, drought, and constant winds, holding on hard against being scoured out and displaced, and ready also, to move into new areas. Beach grass, especially, has this ability to move in on newly deposited sand, or where “blow outs” have occurred, areas in which the wind has finally blown the sand out from under the plants formerly rooted there. So this patchy, heathlike region is held down in substance, temporarily, if not in form, adapted to the constant changes made by the wind. Closer to the cliff’s edge there are likely to be hummocks or mounds, like those of the dunes. A high hummock may be held down by beach grass and have a core of bayberry bushes with only an inch or two of leaves and branches sticking out at the tops. Beach grass, bayberry, seaside goldenrod live in close if embattled communities, at least with respect to the wind. These plants and others may all join in holding such hummocks or mounds together, while the Hudsonia in rounded clumps holds and extends its grounds across the level sand around them. There are two principal species of Hudsonia by the way, ericoides and tomentosa. Both have been called “poverty grass,” but the name is usually applied to tomentosa, which is the more common of the two. They are not always easy to tell apart. The ericoides, sometimes called golden heather, has tiny spinelike leaves that stand out fairly distinctly from the stem and each other and it is a plant that stays green for a much longer time during fall and winter. The tomentosa is densely tufted, downy, softer in appearance, and it turns gray, or bluish green, being subject to winter kill more readily than the other species. On Nantucket at least this plant used to be gathered, dried, and used for fuel.