Crataegus aestivalis, known as the eastern mayhaw, is a shrub or small tree of the southeastern United States that grows in low-lying or wet areas from eastern Alabama to central Florida and Virginia. It is one of several species of hawthorn with fruits known as "mayhaws", which are harvested for use in making mayhaw jelly, considered a delicacy in many areas of the South. Other species of mayhaws include Crataegus opaca, the western May Hawthorn, which is native from east Texas to Alabama.
Crataegus aemula, the Rome hawthorn, is a species of hawthorn that is common in some parts of Mississippi and Georgia, and also occurs in Alabama. It is a perennial shrub or tree. Its habitats include oak flatwoods and brush.
Crataegus fluviatilis is a species of hawthorn similar to C. flabellata and to C. macrosperma. The name C. apiomorpha has been applied to a form of the species that is most similar to C. macrosperma.
Crataegus populnea is a hawthorn native to the northeastern U.S. and southeastern Canada. The flowers have about 10 stamens with red to purple anthers, and the fruit are orange to red, about 1 cm in diameter, spherical or oblong. Crataegus compta is a variant with pear-shaped fruit.
Crataegus ellwangeriana is a named hawthorn species that has been poorly understood and often misidentified. It is now considered to be a synonym of C. coccinea var. coccinea. A study concluded, that C. pennsylvanica of series Molles has frequently been misidentified as C. ellwangeriana.
Crataegus flabellata is a species of hawthorn known by the common name fanleaf hawthorn. It is native to the northeastern United States and adjacent Canada. It is intermediate in appearance between C. macrosperma and C. chrysocarpa. C. macrosperma, which occurs throughout the range of C. flabellata and also in the southeastern U.S., is often misidentified as C. flabellata.
Crataegus pruinosa is a species of hawthorn known by the common name frosted hawthorn. It is native to a wide area of the eastern United States and southern Canada, and is sometimes considered to be several species, rather than just one.
Crataegus putnamiana is a rare species of North American hawthorn derived from hybridization between a species in Crataegus series Coccineae and a species in series Dilatatae.
Crataegus submollis, known as the northern downy hawthorn, northern red haw, Quebec hawthorn, or hairy cockspurthorn, is a species of hawthorn that grows to about 7 m in height and typically carries large crops of red fruit.
Crataegus visenda is a species of hawthorn from the southeastern United States, in Alabama, Florida, and Georgia. It is a large shrub or small tree to 10 m tall. It has been considered as a synonym of Crataegus flava Aiton
Crataegus rufula, or Crataegus × rufula, known as the rusty hawthorn or rufous mayhaw, is a shrub or small tree of the south eastern United States. It is one of several species of hawthorn with fruits known as "mayhaws", which are harvested for use in making mayhaw jelly. It is thought to be a hybrid between the other two species of mayhaw.
Crataegus pennsylvanica, known as the Pennsylvania thorn, is a species of hawthorn native to Delaware, New York, North Carolina, Ontario, Ohio, and Pennsylvania, that grows to about 8 m in height. The mature trees have few thorns.
Series Molles is a series within the genus Crataegus that contains at least six species of hawthorn trees and shrubs, native to Eastern North America. Some of the species are cultivated as ornamental plants. They have relatively large leaves, large flowers, and bloom early for hawthorns. The plant parts are usually hairy, particularly in early growth, and the fruit are generally red and are large for hawthorn fruit.
Series Populneae is a series within the genus Crataegus that contains at least eight species of hawthorn trees and shrubs, native to Eastern North America. Only one species, C. populnea is widespread.
Section Coccineae is a section within the genus Crataegus that includes the majority of North American hawthorn diversity. It includes at least 20 series as well as some species that have not yet been assigned to series.
Series Pruinosae is a series within the genus Crataegus that contains at least six species of hawthorn trees and shrubs, native to Eastern North America. They are similar in some respects to series Intricatae. They are very thorny, with medium to large leaves, and hard fruit that are usually pinkish in colour.
Series Tenuifoliae is a series within the genus Crataegus that contains at least seven species of hawthorn trees and shrubs, native to Eastern North America, with one disjunct species in the mountains of New Mexico.
Crataegus stolonifera is a hawthorn species native to the northeastern U.S. and southeastern Canada.
Section Douglasia is a North American section within the genus Crataegus of species with black fruit.
Section Sanguineae is a section within the genus Crataegus native to central and eastern Europe and parts of Asia. It includes about 20 species and three series.
