Also known as Japanese Holly-fern, Native to Eastern Asia, and escaped cultivation in much of Europe, North America, the Atlantic Islands, Australia, New Zealand, and South America. That’s the kind of thing that can happen when you have a hardy, frost-tolerant ornamental that can also survive as a houseplant.
In the wild it thrives in crevices in coastal cliffs, stream banks, rocky slopes, and other moist, stable areas. In this case, on my last visit back to Sydney, i found at the bottom of rocky outcrops near the shore at Bare Island.
Found among the rocky outcrops in the cliffs overlooking Bare Island, Botany Bay, Sydney. It’s entirely likely that Sir Joseph Banks and his fellow botanical lunatics would have noticed this species as they ransacked the place, but it first appeared in scientific literature in the year 1810, in the Prodromus Florae Novae Hollandiae, published by the prolific Scottish botanist, Robert Brown.
Its habitat is cracks in rocky headlands beside the sea. Check. Its found in eastern Australia and Norfolk Island. Check. Its fronds are thick and waxy to protect it from sea spray. Check again. The specific epithet difforme refers to the irregular shape of the fronds.
Spleenworts earned their common name via the Doctrine of Signatures, a once widespread belief that the medical applications of a plant were determined by shape. Hence other plant names, like liverwort. In the case of these ferns, the sori, or sporing structures under the fronds, are shaped like spleens.
The spleenworts are also famous for their genetics, which can be most easily described as unrestrained bullshit. Even the chloroplast genome has evolved in complex and highly unusual ways that make a laughing stock of traditional cladistic methods, and even very sophisticated computational phylogenetics yield little information on the relationships between species. In addition to hybridization running rampant in parts of this genus, some species like the mother spleenwort mainly reproduce asexually, and while most species are diploid or tetraploid, some like A. shuttleworthianum are octoploid.