Crataegus coccinea var. fulleriana
Phytoneuron 2011–29: 1. 2011.
Leaf-blades broadly elliptic to elliptic-ovate, 4–7 cm (length/width = 1.2), usually plane, rarely concavo-convex, base rounded to broadly cuneate, lobe sinuses often shallow. Stamens 20. Pomes usually suborbicular.
Phenology: Flowering May; fruiting Sep–Oct.
Habitat: Brush, woodland margins, fencerows, overgrown pastures
Elevation: 10–300 m
Ont., Mich., Wis.
The leaf shape of var. fulleriana is somewhat intermediate between var. coccinea, var. pringlei, and Crataegus holmesiana. In J. A. Macklin (2001), the placement of var. fulleriana indicates it is not simply a 20-stamen variant of one of the 5–10-stamen entities. Crataegus confragosa Sargent may represent a glabrate form. Very rare convex-leaved forms might also be interpreted as mutants of var. pringlei.
"glabrate" is not a number.