Where in the world can you find Hildenbrandia?
In short, everywhere (1). H. rubra and H. occidentalis are readily found on both coasts of North America, from Alaska down to Panama, and from New Brunswick down to the Caribbean and other Atlantic islands. H. rubra (recently reported to be non-monophyletic; see Taxonomy) has also been found on both coasts of South America, all over European shores, on both coasts of Africa, on islands in the Indian Ocean, up and down the east coast of Asia, on Australian shores, and on many Pacific islands. This enormous range is most likely attributable either to vage taxonomic divisions or to Hildenbrandia's incredibly flexible ecology.
Where on the shore can you find Hildenbrandia?
In short, everywhere. Hildenbrandia grows on rocks of all shapes and sizes. The habitat in which it is most conspicuous is high intertidal pools (2). But Hildenbrandia can be found in nontrivial abundances in pools and exposed rock literally through the intertidal, and subtidally to at least -12 m for H. rubra and -21 m for H. occidentalis (3). In general, the more physically stressful the habitat, the more likely it is that Hildenbrandia will be growing there (e.g., high pools, sea caves, intertidal cobbles, and freshwater seeps). Hildenbrandia's tolerance of harsh environmental conditions is exemplified by the 5 freshwater congeners (see Taxonomy), whose ability to deal with physical stress has allowed them to escape the ocean.