(The specific epithet is derived from the generic name of the host plant).

Chalara myrsines is distinct from all Chalara species described in the monograph by Nag Rai & Kendrick (1975), those noted by Morgan-Jones & Ingram (1976), Kile & Walker (1987), Kowalski & Halmschlagcr (1996), and from the two species described from the Chatham Islands (C. dracophylli and C. distans) by McKenzie (1993). It is close to Chalara australis Walker & Kile and C. neocaledoniae Kiffer & Delon but differs from both in conidial size and particularly in the collarette:venter ratio (see Table 3 for a comparison [not provided here]).

Most of the remaining stands of indigenous forest on the Chatham Islands are in poor condition, attributable to disturbance by introduced grazing animals which have been permitted to range and browse freely. Exclusion of stock from such stands in recent years has generally led to an improvement in stand vigour. Chalara myrsines was isolated from discoloured wood from the roots and lower stem of dying M. chathamica trees in a mixed stand which were in a state of decline although the stand was fenced off as a reserve. The trees were also being colonised by the pinhole borer Platypus apicalis White and by a pit weevil (Psepholax sp.). Chalara myrsines was commonly but not always associated with the tunnels of these wood-boring insects. Many species of Chalara are known as wilt pathogens (Nag Raj & Kendrick 1975) and it is possible that infection by C. myrsines is one of the causes contributing to the decline of M. chathamica in the Chatham Islands.