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.)

Of conservation concern.

Crataegus flava ranges from southeastern Georgia to South Carolina and northern Florida. Wild specimens of the typical form have not been seen since the early 1900s; vegetative specimens resembling this species were collected from the Florida panhandle in the early part of the present century.

Crataegus flava has been widely confused with members of both ser. Apricae and ser. Lacrimatae (J. B. Phipps et al. 2007). Its stamen number has been wrongly credited as 10 or 20; stamen number in the type has recently been verified as 13–16 by S. Landrein (Kew). Recent collections with 13–16 stamens are unknown. The correct stamen counts are unusual for Crataegus, which are mainly narrowly dispersed around modes of 10 or 20, so this perhaps suggests, together with its somewhat flexuous twigs, and rarity, hybrid origin. Crataegus flava is similar to C. rubella, particularly in fruit shape and color as well as general glandularity, so its placement with members of sect. Intricatae seems appropriate. Lack of recent collections similar to the type suggests that modern attributions to C. flava may represent hybrids involving members of ser. Apricae.

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