Recogn. Ram.: 69 (1870)
Basionym: Lichen aggregatus Sw., Nov. Gen. Pl.: 147 (1788).
Type locality: Jamaica, O.P. Swartz (S - lectotype). Lectotypification by Filson (1981).
Photobiont: Data lacking.
Chemistry: K-, C-, KC-, P-, barbatic acid, fumarprotocetraric acid, ursolic acid, protocetraric acid, 4-0-demethylbarbatic acid (trace) (Filson & Archer 1986: 218).
Ecology: On soil.
Thallus: fruticose, composed of pseudopodetia, variable in size, from as low as a few mm in exposed positions and to 80 mm tall in shertered habitats, hollow, horny, rigid and fragile when dry, dichotomously or irregularly branched, flexuose, prostrate or ascending; colour varied, cream, straw, brown to almost black, walls perforate, perforations round to elliptic, cortex smooth, dull to nitid, fertile pseudopodetia only slightly taller than the sterile pseudopodetia, more intricately branched and perforate towards the tips. Apothecia terminal on short branchlets, sessile, to 0.8 mm diameter, disk slightly concave to flat, matt, brownish-black to black, hymenium to 50 µm tall, brown, paraphyses simple, 1.5 µm diameter, apical cell expanded to 4 µm, asci 48 / 11 µm, ascospores 12 - 15 / 4 - 5 µm, simple, hyaline. Pycnidia on tips of sterile pseudopodetia, ellipsoidal, black, microconidia 5 / 1 µm, curved (Filson & Archer 1986: 218).