Flora of North America species comparison

Varieties 2 (2 in the flora).

Crataegus berberifolia is widespread from Texas to Missouri, Florida, and Virginia; it is particularly abundant in Louisiana.

Crataegus berberifolia is little differentiated from some forms of C. crus-galli, except in indumentum; it has relatively small and less variably shaped leaves. Its distribution is quite different. Intermediates with hairy leaves and glabrous inflorescences or nearly glabrous leaves and hairy inflorescences may represent hybrids with C. crus-galli (where they might be reached in the key). Such a situation is found in C. araioclada. Abrasion of the adaxial leaf pubescence may occur, rendering identification more difficult with fruiting material. Crataegus berberifolia has a plethora of yellow and orange-fruited forms, particularly from southern Louisiana. Crataegus fera and C. tersa are red-fruited, C. crocina yellow. The fruit color in the type is unknown; E. J. Palmer (in specimen annotation) called it yellow-orange. A form with exceptionally white-tomentose leaves near Copenhagen, Louisiana, is probably this species. Crataegus regalis var. paradoxa (Sargent) E. J. Palmer, from Missouri and adjacent Kansas and Arkansas, is probably a hybrid between the deeply serrated 'regalis' leaf form of C. crus-galli and a form of C. berberifolia. Two common forms of C. berberifolia occur, treated here as varieties: var. engelmannii with ten pink anthers and var. berberifolia with 20 cream anthers. Forms with 20 pink or ten cream anthers also occur sporadically.

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

Crataegus macracantha is the most widespread North American hawthorn and one of the more variable. Variation is particularly great in Quebec and Montana. Attempts to package the variation into named taxa have hitherto run into the problems that the type is an illustration of inadequate quality and that authors have been insufficiently aware of the total variation. Two common eastern forms are similar white-anthered and pink-anthered with abaxially glabrous, broadly elliptic-ovate leaves, shallowly and sharply lobed, and fruit ripening directly from green to red; these have the longest thorns in the species, and both have been treated as if typical.

Crataegus occidentalis, a white-anthered, intermontane form with leaves similar to the foregoing usually has shorter thorns and fruit ripening to red through a characteristic orange or salmon stage. Pink-anthered C. pertomentosa, with leaves of a similar shape but abaxially pubescent to tomentose grows on the Great Plains. The last two forms have been treated as varieties. Other striking variants have brilliant red bracteoles or strongly convex leaves (both from Montana) and entire-margined sepals (C. integriloba Sargent from Quebec). Some rare forms have glabrous inflorescences. Some populations in northwestern Montana, otherwise much like a common pink-anthered sympatric form, have glandular petioles and may represent introgression from another species.

Crataegus macracantha often forms suckering thickets in the east.

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