Flora of North America species comparison

Crataegus iracunda ranges from Louisiana to South Carolina and Georgia, and to Virginia, but only at low altitudes. Nearly all records of C. iracunda north of the listed distribution are referable to C. macrosperma or to various species in ser. Populneae.

The distinguishing features of Crataegus iracunda are most evident when it is in flower. The species can be construed as a smaller, more southern, allopatric relative of C. macrosperma distinguished by smaller leaves (particularly at anthesis), more slender thorns, and harder, drier pomes. Its distribution is almost wholly to the south of or in Appalachia, at lower elevations than C. macrosperma. The nearest records of C. macrosperma to the Louisiana populations of C. iracunda are from the Arkansas Ozarks.

Crataegus iracunda has been confused with C. gattingeri (ser. Pruinosae) but is readily distinguished in flower by adaxial leaf pubescence, stamen number, and by lacking the usually attenuate terminal leaf lobes of the latter. However, in fruit, unless the filament bases can be counted, one is left with the less reliable feature of the terminal lobe shape. Confusion with the larger-leaved C. populnea (ser. Populneae) is perhaps possible, but the two species are essentially allopatric and their leaves differ markedly in size and texture.

Earlier attempts to segregate varieties based on leaf size are not taken up here but may have merit as the relatively numerous Louisiana (Crataegus drymophila) form has much smaller leaves than North Carolina specimens.

Variety brumalis (Ashe) Kruschke (Crataegus brumalis Ashe) with syntype material from near Pittsburgh, Pennsylvania, is a different entity. Compared to C. iracunda, it has larger and differently shaped (often more or less truncate-based) leaves, proportionately larger at anthesis, and adaxially subglabrous, conspicuously glandular petioles, and larger flowers. This taxon (as a variety of C. iracunda) is primarily responsible for the northwards extension of the range of the latter species. In fact, north of the Mason-Dixon line, most of the specimens attributed to C. brumalis seen by the author appear to be forms of C. macrosperma.

(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.)