Flower:

Flat-topped, branching cluster of 5 to 15 flowers at tips of branch twigs, emerging after the leaves in mid to late spring. Flowers are ½ to ¾ inch across with 5 round white petals. In the center are usually 5 to 10 stamens with white tips (anthers), occasionally 15 to 20 stamens, rarely about 20 stamens with pink anthers.

The 5 sepals around the base of the flower are narrowly triangular, the edges dotted with glands or with gland-tipped teeth. The cup-shaped hypanthium below the sepals and flower stalks are both usually covered in long, soft hairs, occasionally with short hairs; occasionally the hypanthium is hairless.

Leaves and stems:

Leaves are alternate, 1 to 2¾ inches long, up to about 2¼ inches wide, egg-shaped to nearly round in outline, mostly widest near the middle, rounded to pointed at the tip, mostly wedge-shaped at the base but may be somewhat rounded. Edges are toothed nearly to the base with minute dark glands at the tips of most teeth, and usually have 2 to 5 small but distinct lobes per side. The upper surface is hairless to sparsely covered in stiff, appressed hairs, the lower hairless or with with longer, softer hairs along veins and may become hairless with age. The leaf blade tapers at the base to a narrowly winged stalk about half as long as the blade that is usually hairy on both surfaces with a few to several glands along the edges; the wing does not usually extend to the base of the stalk and stalks may become hairless with age.

Young twigs are hairy, yellowish to gray-brown, turning gray the 3rd year and developing straight to slightly curved thorns 1 to 2½ inches long. Thorns are usually abundant and are shiny dark reddish-brown to blackish when young.

Mature bark is thin, gray to gray-brown and splits into narrow plates. Stems are multiple from the base and may reach 6+ inches in diameter on larger stems. Compound thorns are absent, branches are erect to ascending. Plants may be colony-forming but usually not.

Fruit:

Fruit is fleshy and berry-like, oval-elliptic to round, about 3/8 inch diameter, dull, bright red to dark crimson at maturity, hairy or hairless.

Notes:

Fireberry Hawthorn is the most common Crataegus species in Minnesota, found in a variety of habitats and soil conditions, but most often around forest edges and open grassy or brushy areas in full sun to part shade. It is a rather variable species; Flora of North America (FNA) lists 9 varieties, though these are not universally accepted with some references lumping most vars under a single var. chrysocarpa and others calling at least some them separate species. We are following the current treatment in FNA, with guidance from Welby Smith's book “Trees and Shrubs of Minnesota”. In any case, this can be a confusing species. Note that the distribution of vars in Minnesota is unknown, since few herbarium records are identified to a specific var.

The common traits of Fireberry Hawthorn are: multi-stemmed shrub lacking compound thorns; erect to ascending branches with abundant straight to slightly curved thorns 1 to 2¾ inches long; leaves up to 2¾ inches long, mostly wedge-shaped at the base, egg-shaped to nearly round in outline with 2 to 5 small but distinct lobes on each side, leaf stalks narrowly winged near the tip with at least a few glands and usually hairy on all surfaces; sepal edges dotted with glands or with gland-tipped teeth; fruit oval-elliptic to round, dull, bright to deep red at maturity. The leaves are relatively small compared to some other Hawthorns, often not more than 2 inches long.

The variability mostly comes into play with stamens and hairiness. The vars noted by FNA or the DNR to be in Minnesota are:

• var. chrysocarpa: the most common (probably), 10 stamens with white anthers, flower stalks and hypanthia covered in long, soft hairs, leaf underside hairless or veins variously covered in long, soft hairs, fruit red and hairy at maturity.
• var. faxonii (a.k.a. Crataegus faxonii): 5 to 10 stamens with white anthers, flower stalks and hypanthia densely covered in long, soft hairs, leaf base rounded to broadly wedge-shaped, leaf underside with matted, woolly hairs (tomentose) especially along veins, fruit dark crimson and hairy at maturity. This is on the DNR's list but FNA does not list it present in Minnesota.
• var. blanchardii (a.k.a. Crataegus irrasa var. blanchardii): 15 to 20 stamens with pink anthers, flower stalks and hypanthia covered in short, soft hairs, leaf underside hairless or hairy on veins, fruit red and hairless at maturity.
• var. vigintistamina: 15 to 20 stamens with white anthers, hypanthia hairy, flower stalks covered in short, soft hairs, leaf underside hairless to sparsely hairy, veins hairy, fruit red and hairless at maturity.

Crataegus chrysocarpa is most likely to be confused with Crataegus macrosperma, which also has leaves about the same size and similar in shape, but its leaves are more consistently rounded at the base and always hairless on the underside, leaf stalks and hypanthia both hairless, and flowers have pink anthers, only rarely whitish. By comparison, C. chrysocarpa usually has some hairs along leaf veins and on the hypanthia. C. chrysocarpa may also be confused with C. macracantha, the second most common species in the state, which has leaves with less distinct lobing and a more narrow wedge shape at the base, leaf stalks only up to about ¾ inch long that lack any glands and are more broadly winged near the tip.

A final note on this species' vars: along with taxonomy differences in other references are conflicting descriptions of identifying traits, such as the type and density of hairs (or lack thereof). We cannot begin to resolve these conflicts so have to stick with the FNA treatments until there is more universal consensus.