Pinus echinata, the shortleaf pine, is a species of pine native to the eastern United States from southernmost New York, south to northern Florida, west to eastern Oklahoma, and southwest to eastern Texas. Shortleaf pine has the largest range of the southern US yellow pines, but reaches its ecological maxima around western Arkansas in the Ouachita Mountains. The tree is variable in form, sometimes straight, sometimes crooked, with an irregular crown. This tree reaches heights of 20–30 metres (65–100 ft) with a trunk diameter of 0.5–0.9 metres (1 ft 8 in–2 ft 11 in).