Phymatolithon

Phymatolithon
Phymatolithon calcareum
Scientific classification
Clade:	Archaeplastida
Division:	Rhodophyta
Class:	Florideophyceae
Order:	Corallinales
Family:	Hapalidiaceae
Genus:	Phymatolithon Foslie, 1898
Species
At least 11, including Phymatolithon bornetii Phymatolithon calcareum Phymatolithon elatum Chamberlain, 1990 Phymatolithon laeve Phymatolithon lenormandii (Areschoug) W.H.Adey
Synonyms
LeptophytumAdey, 1966

Phymatolithon is a genus of non geniculate coralline red algae, known from the UK, ^[1] and Australia. ^[2] It is encrusting, flat, and unbranched; it has tetrasporangia and bisporangia borne in multiporate conceptacles. ^[1] Some of its cells bear small holes in the middle; this distinctive thallus texture is termed a "Leptophytum-type" thallus surface, and has been posited as a taxonomically informative character. ^[1] It periodically sloughs off its epithallus, reducing its overgrowth by algae by as much as 50% compared to bare rock. ^[3]

References

1. Chamberlain, Y. M. (1990). "The genus Leptophytum (Rhodophyta, Corallinaceae) in the British Isles with descriptions of Leptophytum bornetii, L. elatum sp. nov. and L. laeve". European Journal of Phycology. 25 (2): 179–199. doi:10.1080/00071619000650171.
2. Wilks, K.; Woelkerling, W. (1994). "An account of southern Australian species of Phymatolithon (Corallinaceae, Rhodophyta) with comments on Leptophytum". Australian Systematic Botany. 7 (3): 183. doi:10.1071/SB9940183.
3. Johnson, C.; Mann, K. (1986). "The crustose coralline alga, Phymatolithon Foslie, inhibits the overgrowth of seaweeds without relying on herbivores" (PDF). Journal of Experimental Marine Biology and Ecology. 96 (2): 127. doi:10.1016/0022-0981(86)90238-8.^{[ permanent dead link ‍]}