 The springs are usually formed of a central, raised mound, 2–3 m high, of saturated peat, supporting a mixture of "Melaleuca" and "Sesbania" trees, with mangroves appearing at the saline and brackish springs.The springs vary in size from 0.1 to several hectares; each spring's mound is generally surrounded by a moat, varying from a maximum depth of 50 cm to isolated shallow pools or just wet soil.Many springs also support small stands of cumbungi with the understories of some dominated by the fern "Achrostichum speciosum".