For the fairy called gruagach, see Brownie (folklore). For the other seaweed called landlady's wig, see Ahnfeltia plicata. For the other genus called mermaid's hair, see Cladophora.
Desmarestia is a genus of brown algae found worldwide. It is also called acid weed, acidweed,[2][3]oseille de mer, sea sorrel,[4]ウルシグサ (urushi-gusa), stacheltang, mermaid's hair, landlady's wig, or gruagach.[5] However, 'sea sorrel' can also specifically refer to Desmarestia viridis. Members of this genus can be either annual or perennial.[6] Annual members of this genus store sulfuric acid in intracellular vacuoles. When exposed to air they release the acid, thereby destroying themselves and nearby seaweeds in the process. They are found in shallow intertidal zones.[6]
Ingesting sulfuric acid can cause severe digestive disturbances.[7] but since sulfuric acid tastes extremely sour, members of the genus are unlikely to be eaten in harmful quantities.[7]
^Warneke, Alex (5 December 2014). "These are a few of my favorite species: Desmarestia". Deep Sea News. Retrieved 12 December 2017. Rightly named "Acid Weed," the internal pH of Desmarestia has been estimated as low as 0.6 pH.
^Dickinson, Carola I. (1963). British Seaweeds. Kew series. Vol. 3. London: Eyre & Spottiswoode. p. 76. OCLC1437555. Retrieved 13 December 2017.
^"Desmarestia". SuriaLink SeaPlants Handbook. Archived from the original on 5 January 2020. Retrieved 13 December 2017.
^ abTurner, Nancy J.; von Aderkas, Patrick (2009). "3: Poisonous Plants of Wild Areas". The North American Guide to Common Poisonous Plants and Mushrooms. Portland, OR: Timber Press. p. 116. ISBN9780881929294. OCLC747112294.