Comprehensive DescriptionRead full entry
A moderately sized, completely terrestrial salamander. The ground color is dark brown or black. A distinct broad yellowish to olive green dorsal stripe runs from the head to the tail, but does not reach the tip of the tail. Light spots occur on the sides. The belly is usually slate gray with white or yellowish flecks (Storm and Brodie 1970; Nussbaum et al. 1983; Petranka 1998). Occasional individuals and some populations are melanistic (black) (Stebbins 1985; Petranka 1998). Modal number of costal grooves is 15 (Petranka 1998). Adults measure from 5 up to 7.5 cm snout to vent length (10 - 15.5 cm total length), (Storm and Brodie 1970; Petranka 1998). Males have a relatively longer tail than females and also possess a mental gland, a raised region on the chin used in courtship (Storm and Brodie 1970; Petranka 1998). Juveniles are 13-16 mm SVL and have a brighter dorsal stripe with sharper edges (Storm and Brodie 1970; Petranka 1998).
Plethodon dunni sometimes co-occurs with the similar P. vehiculum. These species can be distinguished using the stripe that extends all the way to the tail tip in P. vehiculum, but does not reach the tip in P. dunni.(Stebbins 1985).
Melanistic populations in the area of Mary's Peak, Oregon, were described as a distinct species, P. gordoni (Brodie 1970). These populations are not genetically distinct from nearby P. dunni (Feder et al. 1978), and currently these are treated as P. dunni (e.g. Stebbins 1985; Leonard et al. 1993; Petranka 1998).
See another account at californiaherps.com.