[1] The genus is currently monotypic, with a single recognized species, Hobsonia mirabilis.

The type species, H. gigaspora, and H. ackermannii are considered to be synonyms[2] and additional lichenicolous species have now been transferred to the ascomycete genera Hobsoniopsis and Illosporiopsis.

[3] Hobsonia mirabilis is only known in its anamorph form, which is whitish, gelatinous, pustular, and occurs on dead woody plant remains.

[2] The species was formerly of uncertain disposition, but molecular research, based on cladistic analysis of DNA sequences, has shown that it belongs within the Atractiellales.

[1][4] Though originally described from New York, the species is more commonly found in the tropics and subtropics.