Flora of North America species comparison

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.)

Crataegus integra extends from Alabama to South Carolina and is concentrated in the northern half of peninsular Florida. The species is one of the more common members of ser. Lacrimatae in its main area of distribution.

Crataegus integra is relatively variable in leaf shape and is notable for its almost entire leaf blades, the margins of which often have numerous, barely detectible teeth. This species often displays a considerable variety of leaf size even on one short shoot and has more venous leaves than many species of ser. Lacrimatae. One of the most different entities in the C. integra complex is C. sodalis (= C. dolosa). It has densely glandular petioles, denticulate leaf margins, short-shoot leaves broadly elliptic to broadly obovate, and rather large suborbiculate extension-shoot leaves, and perhaps should be considered part of C. alabamensis. It is concentrated in south-central Alabama. Crataegus integra differs from the C. illudens form of C. lassa in its proportionately narrower and usually shorter leaves, lacking the distinctive cuneate-cuspidate shape of C. lassa but also sometimes obscurely subterminally lobed. Crataegus integra is particularly common in the northern half of peninsular Florida, where C. lassa is rare. Crataegus constans Beadle, with less copious inflorescence tomentum, longer petioles, and proportionately larger and thinner leaves, is perhaps a shade form of C. integra.

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