ALGAE 



While in general the Red Sea is comparatively poor in 

 marine flora, where there are favourable environmental 

 conditions the flora abounds. 



Among the green algae {Chlorophyceae) we find the Ulva 

 lactuca, known as sea lettuce (which is common in the 

 Mediterranean and which, with its bright green tufts, does 

 in fact look like lettuce). The Ulva reticulata belongs to the 

 same genus and still under the Chlorophyceae it is possible to 

 include several species of the genera Valonica, Caulerpa^ 

 Halimeda, etc. In the brown algae class {Phaeophyceae) there 

 are numerous species of the Sargassum genus. Masses of these 

 vegetable forms are commonly met on the high seas. They 

 are torn away from the coastal shallows by the waves and 

 their air-filled vesicles keep them afloat. These algae bear 

 a strong resemblance to certain species of terrestrial flora in 

 their somatic form. They have, for example, a rhizoide which 

 is reminiscent of the root of a superior plant, a cauloide 

 which is like the trunk or stem, and filloidi which look like 

 leaves. When you dive into one of these 'submerged planta- 

 tions' of sargassus you really have the impression of moving 

 over or through a forest. Naturally it is a dwarf forest 

 because the algae reach a msiximum height of five feet. The 

 species of the genus Sargassum most commonly met in the 

 Red Sea are latifoliuniy cuneifolium and sentifolium. In the 

 same group of the Phaeophyceae we noted the Padina pavonia 

 which is common along the rocks of the Mediterranean 

 coasts. It was generally found in the calcareous residue of 

 dead madrepore formations on the coast. 



231 



