This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The first zone is made up of sandy coasts, muddy estuaries, rocky coasts, and sea cliffs. Of the plants here described in detail the bulk grow on sandy coasts, as Sea Kale, Sea Rocket (both also growing on shingle), Sea Campion (also on shingle and dunes), Sea Purslane (also on shingle), Tamarisk (also on dunes), Sea Holly, Absinth, Sea Lavender (also in salt marshes), Centaury, Seaside Bindweed (also on dunes), Sea Buckthorn (also on dunes), Grass Wrack (in estuaries in water), Sand Sedge (also on dunes), Crested Dog's Tail Grass, Seaside Manna Grass, Squirrel Tail Grass.
Scurvy Grass grows on muddy coasts, Woad on cliffs, and Samphire and Thrift on rocks, the latter also in salt marshes and on sand. Amongst other plants that are found upon the sandy coasts are Sea Radish, Bloody Crane's Bill, Scotch Rose, often farther inland, Cotton Weed, Small Yellow Gentian, Buckshorn Plantain (also often far inland), Rupture Wort, Sea Spurge, Asparagus, Baltic Rush, Bulbous Meadow Grass. On muddy coasts Beet is to be found. On sea cliffs and rocky coasts the following occur, amongst many others: Queen Stock, Wild Cabbage, Isle of Man Cabbage, Tree Mallow, Lovage, Blue Gromwell, the latter also on shingle.
It is thus evident that the flora of the first maritime zone is of an extremely diverse and interesting character, and that it is highly adapted to travel inland where conditions are suitable, for many are common to the other zones.
The extent of the shingle beaches around the British coasts is strictly limited, therefore the extent of the flora which is established upon them is not great. Furthermore, it is an extremely mobile formation, and the age of the shingle beach is distinctly recent in the majority of cases. Again, the flora is made up largely of the few plants with long far-reaching roots that can establish themselves and adapt their growth to the movement of the shingle, which is liable to frequent additions to or removal of the component pebbles.
A striking feature of the shingle beach is the manner in which laterals are formed at right angles more or less to the main bank, and the part played by plants that help to stabilize the newly-formed shingle, such as Shrubby Sea Blite, is of the greatest interest. The work of this natural shore preserver, ably described by Prof. F. W. Oliver at Blakeney, is of supreme importance.
The plants that are most frequently found upon shingle beaches on the east and south coasts of England are Yellow Horned Poppy, Sea Kale, Sea Rocket, Sea Campion, Sea Purslane, Sea Holly, Orache, Curled Dock, Ragwort, Marram, Seaside Wormwood. The latter in some places, as at Salthouse, helps to establish embryonic dunes where the Shrubby Sea Blite is less dominant.
The sand dune is just as local along the British coasts as the shingle beach. Sand dunes, in the same way as shingle beaches, owe their preservation, once they are accumulated, to the action of a few dominant plants that in this case help to bind them together by the development of long rhizomes which reach far down into and amongst the loose sand, and by interlacing and constant multiplication form a strong and resistant barrier (when compared with the sand) to the further effect of the wind.
Whilst shingle beaches are a direct product of marine action, dunes on the coast are due to aeolian agency, though the material is directly brought into its position upon the coast by the same agency, or the sea. Dunes are if anything of much quicker growth than shingle beaches, and as readily destroyed in the absence of binding Grass rhizomes. So important is the office of Marram, Lyme Grass, etc, in binding the sand together that there was once a law made to prevent these useful plants from being destroyed. In such low-lying countries as Holland such a law is of primal importance.
The plants that are found most commonly on sand dunes are Saltwort (also on sandy shores), Seaside Bindweed, Sea Buckthorn, the Creeping Willow (acting as a sand binder in Anglesey), Sand Sedge (a most useful sand binder), Marram, Lyme Grass, Rushy Wheat Grass, Squirrel Tail Grass. Others not described in detail here are Sea Campion, Sea Purslane, Sea Rocket, and Sandhill Cat's Tail.