Adult Morphology: On average, E. wightmanae measures 19 mm (3/4 inch) in total body length (Rivero 1998), with females measuring a maximum of 22.5 mm SVL (Joglar et al. 2005). The head is slightly smaller than the body, and the eyes protrude from the head (Joglar 1983). Pupils are oval-shaped and horizontal. The tympanum is not distinct. The forelimbs are very slender but the hind limbs are more robust. Digits are long and slender and bear circummarginal discs, with Toe III being the longest on the hind limbs (Joglar 1983). Digital pads are slightly enlarged on the fingers but are much smaller than similar species (E. coqui and E. cooki), which reflects its life on the ground or in small bushes (Miranda-Castro et al. 2000). The texture of the skin on the dorsal surface is fairly warty while the ventral surface is granular (Joglar 1983). Males have a single external vocal sac for calling (Joglar 1983).
Adult Coloration: The dorsal surface is brown or gray in background color, with small dark spots on the back and flanks, and often a tinge of salmon or rosy yellow (Schmidt 1920; Rivero 1998). Limbs are barred on the thighs and tibia (Rivero 1998). The ventral surface is white to a greenish-yellow color (Rivero 1998). The upper eye is golden or golden-gray in color (Rivero 1998). Behind the tympanum is a dark line and on the dorsal surface of the hind limbs are dark bands (Schmidt 1920; Rivero 1998). Males have a gray throat with green flecks, yellow-green abdomen and yellow-green (or yellow with a touch of rosiness or salmon) ventral surfaces on the extremities (Rivero 1998).
Larval Morphology/Coloration: no larval stage; direct development (Joglar et al. 2005).
Species authority: Smith (1920).
Phylogenetic Relationships: Joglar (1983) examined the phylogenetic relationships within the Eleutherodactylus genus of Puerto Rico. In this paper, E. wightmanae was classified into the auriculatus group, along with ten other species. Morphological characters defining this group included a granular abdomen, patches of vomerine odontoids , well-developed toe pads, and vocal sacs in males. Ecological characteristics of this group included having a male advertisement call, and calling from above the ground. E. wightmanae was found to be most closely related to E. eneidae, E. portoricensis, and E. coqui.
Etymology: Eleutherodactylus is derived from a Greek word meaning "free-toed," while wightmanae honors Margaret Wightman Schmidt, the wife of the scientist who discovered this frog in 1919 (Schmidt 1920).