Leiobunum politum is a species of harvestman in the family Sclerosomatidae. It is a medium-sized North American species widely distributed in the eastern and southeastern United States, and is especially common in the Appalachian Mountains.
Leiobunum politum is a medium-sized harvestman. Males are about 3.5âÂÂ5.0 mm in body length and females about 4.5âÂÂ6.5 mm. The body is generally yellow-brown, with a dark brown to black ocular tubercle bearing small sharp spines.
Males usually lack prominent dorsal markings, while females may show a variably developed median abdominal mark. The species can be distinguished from closely related species by the morphology of the male penis and the size of the genital operculum.
Leiobunum politum occurs widely across the eastern and southeastern United States. It has been reported from the Appalachian Mountains from Maryland south to northern Florida, and westward into Mississippi, Louisiana, eastern Arkansas, and Illinois.
Specimens have been collected throughout much of the Appalachian region and adjacent areas, where the species inhabits forested habitats.
Leiobunum politum was originally described by Clarence M. Weed in 1889 from Champaign County, Illinois. Early descriptions relied heavily on characters such as body size, leg length, and coloration.
Later studies found that many of these characters are highly variable and not always reliable for distinguishing species of Leiobunum. McGhee (1977) demonstrated that some specimens previously identified as L. politum actually represent the similar species Leiobunum bracchiolum, which had often been confused with it due to overlapping external features.
More reliable characters for separating the species include the morphology and size of the male penis and the length of the genital operculum.