Vines have insufficient cells with secondary cell walls to resist bending and stems buckle without external support. Some vine species have furrowed xylem that may have less mechanical support compared with vine species with normal xylem. Analyses were performed to quantify anatomical differences between vine stems with and without furrowed xylem. Seven species with and 13 species without furrowed xylem were analyzed with standard histological procedures. The first analysis was done with tissue samples of two furrowed xylem Aristolochia species that had stem areas from 5 to 30 mm². Xylem and sclerenchyma areas increased as stem areas increased so that the largest stem samples had the 20–30% xylem and 20% sclerenchyma areas. These percentages were typical for all the furrowed species. The second analysis compared 5 mm² area terminal stem samples of furrowed and nonfurrowed species. Mean xylem areas of samples with and without furrows were 1.28 and 2.11 mm², respectively. For these samples, results of a t-test produced no statistically significant differences between these two groups even though xylem comprised 18.7% and 35.0% for stems with and without furrows, respectively. All species with furrowed xylem had peripherally located sclerenchyma layer that formed a continuous ring within 10% of the stem surface, while vine species without furrowed xylem had no sclerenchyma. The sum of xylem and sclerenchyma areas in furrowed species were similar to the area of xylem in non-furrowed species. The data suggest that sclerenchyma cells provide significant resistance to stem bending in vines.