Fronds of the earth
Amid the flotsam and jetsam on our beaches lies a rich abundance of brown, green and red seaweeds, many of which can be put to good culinary and cosmetic use, recommends naturalist John Wright
Take another look at our native seaweeds, urges John Wright
Rather surprisingly, there is a (small) canon of poetry about seaweed. Some are firmly in the Moby Dick school of literature and a few dwell tumescently on the unsuitability of seaweed as clothing for sea nymphs. Most, however, speak only of seaweed’s most notorious characteristic: its smell. Sadly lacking is any reference to the astounding beauty of seaweeds; no one paddled lonely as a cloud.
Should you feel inclined to remedy this dereliction of poetic duty, this is what you need to do. Go to a rocky shore on a bright day in late spring when there has been almost no wind all week and there is a low, spring (big) tide. Find a rock pool and put on your most fetching neutral-colour, polarising sunglasses.
the many browns, greens and reds of the seaweeds are naturally arranged for greatest artistic effect and currents and small waves
dramatically change the view every few seconds as the fronds slip over one another and the light changes. Flashes of iridescent blue from the tiny clustered bubbles of oxygen that collect on the seaweed fronds sometimes outshine those sombre colours. No gardener can match the perfection of beauty found in a rock pool.
That seaweeds are beautiful is beyond dispute, but what are they? Seaweeds have proved troublesome to biologists, as it’s not easy to say where they belong in the great scheme that is life. The great classifier, Linnaeus, lumped them all with the plants in a section he called the
cryptogamae. His classification depended on reproductive organs (the stamens and pistil of flowers), yet seaweeds conspicuously lack flowers. Linnaeus was fond of sexual references and cryptogamae means ‘hidden marriage’, because he couldn’t see what was going on.
Seaweed is really a name of convenience for what is, in truth, a group of unrelated organisms. ‘Seaweeds’ refers to an ecological group. Within this informal group are brown, red and green seaweeds, respectively the Phaeophyta, Rhodophyta and Chlorophyta. The important point here is that these three are as distantly related to each other as plants are from animals! The Chlorophyta are classified as plants, the Rhodophyta with things such as slime moulds and the Phaeophyta find themselves on an obscure branch on the tree of life, unmemorably known as the SAR supergroup.