5d. ssp. schneckii (Rehder) Desmarais

A. saccharum var. schneckii Rehder

A. saccharum f. schneckii (Rehder) Deam

A. saccharum f. rugelii (Pax) E.J. Palmer & Steyerm.

A. nigrum F. Michx. var. schneckii (Rehder) Fosberg

Bark gray to dark gray or brown, somewhat roughened, becoming deeply furrowed and sometimes with peeling ridges on older trees. Leaf blades 6–15 cm long, the undersurface pale green, bluish green, grayish green, or whitish, sometimes glaucous and hairy along the veins, the lobes tapered but bluntly pointed or rounded at the very tip, usually lacking or with very few secondary lobes or teeth, the sinuses between the main leaf lobes mostly forming angles of less than 90°, the margins sometimes slightly curled under. Calyx frequently hairy, but without dense white hairs on the inner surface that extend past the lobes. Flower stalks elongating to 5–10 cm, usually hairy. Ovary and young fruit glabrous. April–May.

Uncommon in eastern and southern Missouri (Indiana to Wisconsin south to Tennessee and Missouri). Mesic to dry upland forests, margins of glades, ledges and bases of bluffs, and banks of streams.

Trees of ssp. schneckii tend to combine features of ssp. floridanum, ssp. nigrum, and ssp. saccharum, although visually they resemble ssp. nigrum most closely. They have the relatively shallowly lobed, dull leaves typical of ssp. nigrum but lack the yellowish green undersurfaces. The lobes are tapered but are blunt or even rounded at the very tips. In Missouri, trees are usually found as scattered individuals in areas where other subspecies are more common. Thus, there are some questions as to the status of this subspecies. Some authors, such as Gleason and Cronquist (1991) have expanded the definition of ssp. schneckii to include plants otherwise assignable to ssp. saccharum but with hairs on the leaf undersurfaces. However, this definition seems too broad and deviates from the original concept of ssp. schneckii (Desmarais, 1952; Steyermark, 1963); if it were adopted, nearly all Missouri sugar maples would have to be included in it.