Among the molds, grouping them can be done - by their mycelia (the hyphae forming the vegetative portion of the fungus as opposed to the aerial portion). These hyphae can be referred to as septate (having cross-walls) or
aseptate (without cross-walls).
Molds with septate hyphae are then grouped by their color as either hyaline (light-colored or lacking color) or
dematiaceous (pigmented).
In this course, the hyaline molds will be further subdivided into the scientific order Mucorales (containing the Mucormycetes, formerly known as Zygomycetes) - many of which are aseptate, the Dermatophytes, and the Other Opportunistic Hyaline Molds. The dematiaceous molds will be subdivided into slow-growing (typically more pathogenic) and fast-growing (usually, but not always, less pathogenic).
