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.