Flora of North America species comparison

Varieties 6 (6 in the flora).

Crataegus pruinosa extends from Arkansas to Wisconsin, through the southern Great Lakes to southern New England, and, in the south, mainly in the Appalachians to northern Georgia.

In the north of its range, Crataegus pruinosa is mainly a shrub of open successional habitats but in the south may commonly be a taller tree of open or thin woodlands.

Many hawthorns have a little waxy bloom on their pomes; it is particularly prominent on Crataegus pruinosa and C. cognata compared to others. Some authors include in C. pruinosa their white-anthered counterparts, here assigned to C. cognata. Whereas C. pruinosa characteristically has entire or subentire sepal margins, some forms in the southwest of the range of the species (for example, C. calliantha Sargent, C. seducta Sargent) may have glandular-serrate sepal margins. They may represent introgression with C. coccinioides. The varieties of C. pruinosa are weakly differentiated from each other, most of them on leaf shape and size characters. The more widespread varieties constitute a range of morphotypes held together by common traits. Crataegus gaudens Sargent is a strikingly distinct form from Pennsylvania that has more or less elliptic leaves with lobes absent; it is clearly related to C. pruinosa. Note that 159. Crataegus ×coleae, a Michigan endemic, will key out here if its laterally scarred pyrenes are missed.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Crataegus castlegarensis occurs from around the northern Okanagan, British Columbia, to the northern California Coast Ranges, to northwestern Montana, and the Rocky Mountains to northeast of Salt Lake City, Utah. The species occurs also in the Cypress Hills of Alberta and Saskatchewan; it is found in habitats similar to those of C. douglasii and is at least as abundant as that species in a number of parts of its range.

Crataegus castlegarensis is readily recognized by a combination of hairy inflorescence branches, pomes more or less orbicular, crimson or burgundy (with irregular earlier ripening) around the third week of August, soon becoming purple, often when nearby C. douglasii is already black, as well as a tendency to possess thorns on the young twigs branched at the base to become double, triple, or even sometimes quadruple. Such multiple thorns, though sometimes abundant on a bush, are more often few and may require searching for. Inflorescence pubescence, as in other species with this characteristic, may become sparse by fruiting. Crataegus castlegarensis is most similar to C. douglasii; its fruit is usually more orbicular, even oblately so, than is normal in that species, sometimes even with a recessed junction to the pedicel like an apple.

(Discussion copyrighted by Flora of North America; reprinted with permission.)