Banksia littoralis, commonly known as the swamp banksia, swamp oak, river banksia or seaside banksia and the western swamp banksia, is a species of tree that is endemic to the south-west of Western Australia. The Noongar peoples know the plant as pungura, boongura or gwangia. It has rough, crumbly bark, linear, more or less serrated leaves arranged in whorls, yellow flowers and up to two hundred follicles in each head.
Banksia littoralis
Banksia littoralis near Bunbury
Illustration from The Botanical Magazine (1831)
Banksia seminuda, commonly known as the river banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from Dwellingup (32°42′ S) to the Broke Inlet east of Denmark (34°57′ S). It is often mistaken for, and was originally considered a subspecies of, the Banksia littoralis. Stephen Hopper described the subspecies remanens as a short-leaved shrubby form found in the coastal sands below granite outcrops in the Walpole-Nornalup National Park, however George does not feel this form warrants taxonomic recognition as it lies within the normal variability of the species and there was no clear distinction between it and the other populations of B. seminuda.
Banksia seminuda
Red-flowered form in late bud
fissured trunk on 20-year-old tree, Banksia Farm, Mount Barker, WA