Vine vigorous, sometimes climbing high upon trees, sometimes forming a bushy clump from two to six feet high; canes cylindrical, much rusty wool on shoots; tendrils intermittent. Leaves very large, almost as wide as long; entire or three-, five-, or rarely seven-lobed; lobes frequently divided; sinuses, including petiolar sinus, deep; smooth above, and with more or less rusty pubescence below. (The north-Texas, southwestern Missouri and northern Arkansas form shows little or no pubescence but has fine prickly spines at base of shoots and shows much blue bloom on shoots, canes and the under side of the leaves.) Fruit small to large, usually larger than typical AEstivalis, usually black, with heavy bloom. Seeds larger than AEstivalis, pear-shaped; chalaza roundish. Lincecumii inhabits the eastern half of Texas, western Louisiana, Oklahoma, Arkansas and southern Missouri on high sandy land, frequently climbing post-oak trees, hence the name, post-oak grape, by which it is locally known. Lincecumii has attracted considerable attention through the work of H. Jaeger and T. V. Munson in domesticating it, both of whom considered it one of the most, if not the most, promising form from which to secure cultivated varieties for the Southwest. The qualities which recommend it are: First, vigor; second, capacity to withstand rot and mildew; third, hardiness and capacity to endure hot and dry summers without injury; fourth, the large cluster and berry which were found on certain of the wild vines. The fruit is characteristic because of its dense bloom, firm, yet tender texture and peculiar flavor. The cultivated varieties have given satisfaction in many sections of the Central Western and Southern states. Like AEstivalis, it is difficult to propagate from cuttings. The north-Texas glaucous form of this variety mentioned in the technical description above is the _V. aestivalis glauca_ of Bailey. This is the type of Lincecumii that Munson has used in breeding work. _Vitis aestivalis Bourquiniana_, Bailey. Southern AEstivalis.