THE COAST-FLORA OF ESSEX.
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junceum) and Sea-barley (Hordeum marinum) are perhaps the most
characteristic grasses on the sides of the walls, and the rare Sea-
heath (Frankenia laevis) may occasionally be found.
On those parts of our coast which are fringed by sandy
shores and sand-dunes, we find another variety of plants, also
arranging themselves in zones. On the sandy beaches, just
above high-water mark, we find such plants as the Saltwort
(Salsola kali), several species of Atriplex peculiar to these sandy
beaches, such as the Frosted Sea-orach (Atriplex babingtonii), the
:Sea-campion (Silene maritima), Sea-purslane (Arenaria peploides),
the Sea-Spurry (Spergularia maritima), the Sea Convolvulus
(Convolvulus soldanella), the Horned-poppy (Glaucium luteum), and
the Sea-holly (Eryngium maritimum). The borough of Colchester
was formerly celebrated for preparing a Candy from the roots of
the last-named plant, and we learn from the Colchester Borough
Accounts that the sweetmeat was so highly esteemed as to have
been frequently presented by the borough to Royal and other
eminent persons. The pretty golden Stonecrop or Wall-pepper
(Sedum acre), the Sea-kale (Crambe maritima), a much-valued vege-
table, and other plants also occur. On the sand-dunes themselves,
we have the Sea Lyme-grass (Elymus arenarius), the Marrum-
grass (Ammophila arenaria), the Sea Sedge (Carex arenaria), and
other grasses and sedges with creeping roots, which serve to hold
the sand-hills together and prevent their being washed away by
the tides or blown away by the winds. Plants growing in
such situations must possess the power to reach the surface
again if occasionally buried by the sand. In some countries,
those who damage these grasses are punished by heavy penalties.
Behind our sea-walls and sand-dunes, we find extensive
marshes, separated from one another by deep dykes filled with
brackish water. These dykes affords us another characteristic
flora. We find in the marshes, or in their immediate neighbour-
hood, such plants as the rare Hog's-fennel (Peucedanum officinale),
the Slender Hare's-ear (Bupleurum tenuissimum), the Tassel-
pondweed (Ruppia maritima), the Alexanders (Smyrnium
Olusatrum), so highly valued by our ancestors as a pot-herb, and
the Wild-celery (Apium graveolens), an unwholesome weed which
when cultivated becomes one of our most valued vegetables,
the poisonous Water-dropwort (Oenanthe lachenalii), and many
other plants, which flourish near the brackish ditches.