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 The
heath-like ericoid growth form comprises about 3 000 species, including
the family Ericaceae and many of the largest fynbos genera such as Aspalathus, Agathosma, Cliffortia, Muraltia and Phylica. The great majority
of species of genus Erica in the world are endemic to South
Africa. There are some 667 species of Ericas in the Western Cape,
giving them the highest degree of regional speciation on earth. Ericas
may have evolved after the breakup of Gondwanaland, because they do not
appear in either South America or Australia.
Click
on the picture to see some of the Ericas found at Wildcliff, from an
initial survey by Gael and Roger Gray.
Most of the Ericas
are smallish shrubs with small, hard, needle-like, often down-rolled
leaves with the stomata being positioned inside a very narrow slit,
upper surfaces which are hard and waxy, and delicate tubular flowers
The leaf characteristics are fairly common features of the Ericas
and are an adaptation to minimize water loss. Erica flowers have
eight anthers and four petals joined to form a tube or cup.
With one
of two exceptions, the ericoids store their seeds in the soil. About 80% of the
Ericas are insect-pollinated, and the pollinators are often flies. Another
characteristic of the Ericas is that they have evolved a symbiotic
relationship with fungi which helps them to maximize nutrient
absorption in the relatively deprived soils of the Cape.
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