About Lithophyllum incrustans Philippi, 1837
Lithophyllum incrustans Philippi, 1837 is a small, encrusting calcareous alga. It grows epiphytically as a flat, lobed plant that forms thick, adherent crusts, reaching up to 10 cm in diameter and up to several millimeters thick. Its lobes may overlap, giving the alga a knobbly texture, and it has a smooth surface. It is typically pinkish in color, but individuals may become bleached. This species is found all around Great Britain, Ireland, the Isle of Man, and the Channel Islands, and is rarer on the east coast of England. Within Europe, it has been recorded from the Faroes, and ranges from Norway to the Mediterranean. For reproduction, tetrasporangial and bisporangial conceptacles form in sunken pits. Most individuals are gametangial; spermatangial conceptacles develop in shallow chambers, while carposporangial chambers are flask-shaped. It is common in shallow pools and under cover, and grows abundantly from the mid-littoral zone down to 8 metres depth.
