The majority of the human opportunistic fungi of "Cladophialophora" can be found within "Herpotrichiellaceae" which forms two major clades. The first clade, is known as the "C. carrionii"-clade and contains the species "C. carrionii" and "C. boppii". The second clade, the "C. bantiana" clade includes the species "C. bantiana, C. devriesii, C. mycetomatis, C. immunda, C. emmonsii, C. saturnica" and "C. arxii." It has been found that the environmental strain "C. minourae" is a sister strain to "C. arxii"   "Cladophialophora" is a genus of black yeast fungi whose natural habitat consists of soil and rotting plant material. Several of the species pertaining to the "Cladophialophora" have been reported in both tropical and subtropical regions of the world. "Cladophialophora arxii" is a clinical strain that has generally been found in humans "C. arxii" is also capable of acting as an opportunistic fungus of other vertebrates. "C. arxii" is a slow growing fungus that grows to about 36-40 mm in size when cultured on a growth medium of SDA agar and PDA agar at 25° C over a span of 35 days. The colonies formed contained dark grey aerial hyphae and black-brown coloured hyphae located on the margins of the SDA agar. On the PDA the colonies were dark black-brown with felty radial furrows. The fungus contained olive brown septated hyphae with both lateral and terminal acropetal conidial chains with branching. The overall morphology of the conidia of "C.arxii" are very similar to "Cladophialophora devriesii" the conidial chains of "C.arxii" are longer. Additionally, the conidial chains are fragile and borne on dentricles. The conidia of "C.arxii" are pale brown, smooth, thick walled with a lemon-spindle shaped morphology. Initially the fungus contained muriform cells from tissue samples but following corticosteroid therapy the cells changed their shape and become irregularly shaped hyphae.