3b. var. rubrum

A. rubrum var. trilobum Torr. & A. Gray ex K. Koch

A. rubrum var. tridens A.W. Wood

A. rubrum f. tomentosum (Desf.) Dans.

Leaf blades with the undersurfaces lighter than the upper surface and often strongly white-glaucous, glabrous to sparsely hairy when young, glabrous or rarely sparsely hairy along the main veins at maturity. Fruits with the wings 1.5–2.5 cm long. 2n=78, 91, 104. March–April.

Scattered to common in the Ozark, Ozark Border, and Mississippi Lowlands Divisions (eastern U.S. west to Illinois, Missouri, and Texas; Canada). Mesic to dry upland forests and ledges of bluffs, rarely in bottomland forests, sinkhole ponds, and banks of streams.

The leaf blades in var. rubrum generally are glabrous or nearly so at maturity, the few hairs that were present initially having disappeared during development. Steyermark (1963) noted the existence of a few specimens from Camden, Douglas, and Shannon Counties that retained moderate leaf pubescence but had the smaller fruits typical of var. rubrum. He assigned these to f. tomentosa, which occurs sporadically throughout the overall range of the species. Vegetative samples of such plants might easily be mistaken for var. drummondii.