Type: Radicicolous Fungi; Description: Colonies on agar white and cottony at first, becoming brownish black. Chlamydospores intercalary or terminal, usually in a series of 5–7, soon breaking apart, short-cylindrical, 0-septate, 6–14 × 9–13 μm, dark brown, smooth. Conidio-phores erect, branched a few times, 3–5-septate, 70–95 μm long, subhyaline to pale brown, each terminating in a phialide; phialides lageniform, 55–80 μm long, sub-hyaline. Conidia extruded in long chains, cylindrical, 8–19 × 3–5 μm, with truncate ends, hyaline to pale brown.

Distribution: Northland, Auckland, Bay of Plenty, Taranaki, Wanganui, Wellington, Gisborne, Hawkes Bay, Nelson, Marlborough.; 1st Record: Anonymous (1944).

Significance: Of no importance in forestry. This fungus is an important pathogen of tobacco.; Host(s): Acacia baileyana, A. riceana, Actinidia deliciosa, ×Citroncirus webberi, Daphne odora, Lupinus angustifolius, L. luteus, Passiflora edulis, Rhododendron sp., Telopea oreades × speciosissima, Ulex europaeus, Vaccinium corymbosum, Vitis rupestris.

Results of this study, which included analyses of sequences for six gene regions and a large collection of isolates, confirmed the previous findings of de Beer et al.(2014) that the important root pathogen T. basicola is unrelated to species of Thielaviopsis in the Ceratocystidaceae. This provided adequate support for the establishment of a new genus for these isolates, and this study consequently introduces Berkeleyomyces for them. Furthermore, a relatively large global collection of isolates of T. basicola was shown to represent two distinct phylogenetic lineages. Based on a decision relating to the geographical occurrence of the fungus first described by Berkeley & Broome (1850), one of these taxa represents T. basicola sensu stricto. It is now treated as B. basicola and a reference specimen has been assigned for it (CBS 142796). The lineage accommodating the remaining isolates has been described as the new species B. rouxiae.