Page 251 - (DK) Ocean - The Definitive Visual Guide

MOSSES 249

Mosses Anatomy

Most mosses have a recognizable structure of stems and leaves, which,
MOSSES ARE LOW-GROWING plants
DOMAIN Eucarya as in other plants, gather sunlight and perform photosynthesis. However,
that thrive in damp habitats on land, unlike flowering plants (see p.250), they do not have woody tissues for
KINGDOM Plantae
where they may carpet the ground or support, and they also lack the conducting tissues that transport water
DIVISION Bryophyta rocks. They dislike salty environments and nutrients. Mosses have a very thin outer layer of cells, or cuticle, that
SPECIES 13, 365 and only a few species manage to live can absorb (and lose) water, nutrients, and gases over their entire surface.
in the intertidal zone of coasts, mainly Their “roots” are simple strands called rhizoids, which anchor the plant
to its growing surface. Mosses
in cooler climates. A much wider variety of mosses can be found SPORE PRODUCTION
reproduce sexually by means of
slightly farther inland, away from the direct effects of sea spray but Mosses have low-growing leaves, but sprout
wind-blown spores, or asexually taller structures with bulbous tips called
within range of moisture-laden sea mists.
by spreading across the ground. capsules, from which spores are released.
Habitats

Mosses generally prefer moist, shady places and are most numerous in
the cooler and damper climates of temperate regions. This is because
they lack the thick cuticle that enables other types of plant to retain
moisture. Without the protection of this skinlike surface, mosses soon
shrivel up in dry conditions. However, some mosses have an amazing
capacity to recover quickly when wetted after a long period of
drought. A few species grow in salt marshes or among the lichens at
the top of rocky shores; on sheltered coasts, where there is little salt
spray, they may live only just above the high tide level. Sand-dune
mosses grow rapidly to keep pace with accumulating sand, and blown
fragments of moss can colonize
new areas of dunes. Many more
moss species grow on sea cliffs
and in damp gullies away from
the intertidal zone.

SYNTRICHIA RURALIFORMIS
This moss grows in coastal sand
dunes. Its leaves curl up when dry
(left of picture) but unfurl a few
minutes after wetting (on right).

CLASS BRYOPSIDA CLASS BRYOPSIDA CLASS BRYOPSIDA the highest tides. Seaside moss appears
to be a true halophyte, functioning
Golden Dune Moss Salt Marsh Moss Seaside Moss normally even after immersion in sea
water for a few days, and growing
Syntrichia ruraliformis Hennediella heimii Schistidium maritimum only in saline conditions; in Britain,
SIZE / 2 –1 / 2 in (1–4 cm) SIZE / 8 in (3 mm) SIZE 1 in (2 cm) it is found no farther than 1,300 ft
1
1
1
(400 m) from the sea. Its leaves curl
FORM Yellow-green to FORM Single green FORM Dark blackish
orange-brown cushions plants green, compact cushions when dry. In winter, it produces small
and carpets brown capsules on short stalks.
HABITAT Salt marshes, HABITAT Hard, acidic
HABITAT Mobile dunes other coastal areas rocks, salt marshes
DISTRIBUTION Eastern Pacific, northwestern Atlantic, DISTRIBUTION Patchy distribution on temperate and DISTRIBUTION Western and eastern coasts of
Mediterranean cool waters worldwide North America, coasts of western Europe
This is one of the first mosses to This tiny moss is a halophyte, meaning This moss grows as small, dark
colonize mobile dunes. It often forms it is adapted to growing in highly green cushions on hard, acidic
extensive colonies that cover many saline conditions. It is rarely found rocks, with seashore lichens,
square yards of sand, giving the sand growing inland. One of the few just above high-tide mark.
a golden tinge. Its leaves are covered mosses that may be regularly found in It also occurs in salt marshes.
by hundreds of small papillae that salt marshes, it grows on patches of It is often soaked by salt spray
enable swift absorption of water. bare ground between the other and occasionally covered by
The leaves gradually taper into long vegetation in the upper parts of the
white hair points. This moss is able salt marsh. It also grows in various
to establish new plants from fragments other coastal habitats, including the CLASS BRYOPSIDA This moss is the southern version
dispersed by the wind. banks of creeks, behind sea walls, and of seaside moss (see above), growing
on footpaths. Although small, the Southern Beach Moss on coastal rocks in the usually
plants may be abundant and may lichen-dominated splash zone, where it
appear conspicuous from a distance, Muelleriella crassifolia is often inundated by the sea in stormy
due to their prolific number of stout, SIZE weather. It grows in southern Chile
dark, rusty-brown capsules, which are 1–5 in (2–13 cm) and on subantarctic islands, where
borne on short stalks less than /2 in FORM it can become dominant. On Heard
1
(1 cm) tall. These have a little cap with Black cushions and mats Island, for example, a salt spray
a long point, which lifts to allow HABITAT community of plants found on OCEAN LIFE
spores to escape, but remains attached Rocks exposed coastal lava rock, at elevations
to the capsule by a central stalk. The DISTRIBUTION Southern tip of South America, of less than 16 ft (5 m), is dominated
Salt marsh Moss has a wide islands in the Southern Ocean by southern beach moss, which has
distribution in colder climates. also colonized derelict buildings.