THE ECOLOGY OP PLANTS. 435 



rules : the Sea-poppy has large yellow flowers, and the Sea- 

 thrift has a persistent membranous calyx, which forms a 

 funnel-like wing on the fruit. 



Coast vegetation varies according to the nature of the soils, 

 and we find that shifting sands, sand-banks or " dunes," 

 rocks and cliffs, shingle or pebble beaches, and muddy salt- 

 marshes have each their own typical plants, though there are 

 of course transitions from one to the other. 



It is not easy to say just where the sea-shore begins from the land 

 side. It may be limited by cliffs or hills, so that there is little shore 

 and the high tides come up the face of the cliffs ; or it may reach for 

 miles inland among salt-marshes and ditches. Even when the shore is 

 well limited, we find on approaching it that trees become scarce 

 (except in sheltered inlets like those on the Devonshire coast) and are 

 usually gnarled, bent away from the prevailing wind, and often covered 

 with the characteristic rock-lichens found on the coast ; the ordinary 

 flowers of meadows are largely replaced by various Grasses, Rushes, 

 Sedges, and the typical maritime plants, though many inland species 

 come close to the sea. The operations of gardening and agriculture 

 have caused many plants to take to the seaside as a refuge (e.g. Hen- 

 bane, Teasel), and have removed plants like Sea-kale and Asparagus 

 inland into cultivation. Chenopodiaceae (the Goosefoot family, in- 

 cluding Goosefoot, Beet, Saltwort, Sea-blite, Marsh Samphire, Orache) 

 arid Crucifers are especially well represented in the shore- vegetation, 

 but most of the larger families have seaside representatives. 



412. On rocks and cliffs we generally find Sea Plantain 



(Plantago maritima, with entire smooth fleshy leaves), Stag's- 

 horn Plantain (P. coronopus, with lobed hairy leaves), 

 Scurvy-grass (Cochlearia) , Samphire (Crithum), Yellow 

 Stonecrop, Sea Wormwood, Sea Thrift (Armeria, with 

 heads of pink flowers), Sea Bladder Campion (Silene 

 maritima), etc. Several of these (Thrift, Sea Campion, 

 Scurvy-grass, and Sea Plantain) occur also on hills inland, 

 but not in the low-lying parts between the hills and the coast. 

 Their xerophilous adaptations enable them to grow in both 

 kinds of habitat. 



Trees are rarely found on cliffs, but in addition to the 

 plants just mentioned we get many plants belonging to dry 

 grassy pastures (Carline Thistle, Bock-rose, Milkwort, Agri- 

 mony, Bird's-foot Trefoil, Lady's-fingers, Thyme, etc.) ; also 

 plants of the shaded stream-sides, which have been carried 

 to the coast and find sheltered and moist places suited to 



