Waxy-Fruited Hawthorn
Crataegus pruinosa
Rose family (Rosaceae)

Description: This species is a shrubby tree about 10-20' tall, branching irregularly and widely. The small trunk is up to 8" across with gray bark that is rough and scaly. Branch bark is gray and more smooth, sometimes appearing glaucous. Young twigs are reddish brown and smooth; they are usually crooked. Long thorns up to 2" long appear occasionally among the branches and twigs; they are usually straight, but sometimes slightly curved. The alternate leaves are 1-2" long and 1-2" across; they are oval-ovate or oval-deltate in shape and widest below the middle. The leaves are rounded, truncate, or slightly cordate at the base, and they have broad-pointed tips. Leaf margins are shallowly cleft with 3-4 lobes on both sides and doubly serrated. The upper surface of the leaves is blue-green, green, or yellowish green, while the lower surface is more pale; both surfaces are glabrous. Small emergent leaves are often reddish before they assume the coloration of mature leaves. Leaf venation is pinnate; the primary lateral veins terminate at the tips of the teeth and lobes, rather than their sinuses. The slender petioles are relatively long (-2" in length), light green to red, and hairless.

Short-stalked corymbs of flowers are produced from the axils of the leaves; usually only a few flowers are produced per corymb. The peduncle and pedicels of the corymb are light green and glabrous. Individual flowers are -1" across, consisting of a light green calyx with 5 lanceolate teeth, 5 white petals, 20 stamens, and a pistil with 3-5 styles. The calyx is hairless; its teeth have serrated margins. The anthers of the stamens are pink (less often yellow); they become brown with age. The blooming period occurs during late spring for about 2 weeks. Fertile flowers are replaced by small globoid pomes (about " across) containing 3-5 seeds. Pomes become mature during the fall. At this time, they have a red to purple exterior that is glabrous and sometimes glaucous; the fleshy interior is dry and hard. Waxy-Fruited Hawthorn spreads by reseeding itself.

Cultivation: The preference is full to partial sun, mesic to dry conditions, and soil containing loam, clay-loam, or rocky material. For some species in this genus, cedar-apple rust can discolor and weaken the foliage.

Range & Habitat: Waxy-Fruited Hawthorn is occasional in NE, east-central, and southern Illinois, while in other areas of the state it is uncommon or absent. However, it may be more common than records indicate. This species is native to Illinois and other areas of eastern United States. Habitats consist of upland rocky woodlands, upland savannas, woodland edges, thickets, fence rows, and abandoned pastures. Like many other hawthorns, this is a pioneer species that spreads into disturbed areas where there is sufficient sunlight.

Faunal Associations: The nectar and pollen of the flowers attract primarily bees and flies; to a lesser extent, wasps, beetles, and butterflies also visit the flowers. Bee floral visitors include honeybees, bumblebees, little carpenter bees (Ceratina spp.), Halictid bees, and Andrenid bees, while fly floral visitors include Syrphid flies, dance flies (Empis spp., Rhamphomyia spp.), blow flies (Calliphora spp., Lucilia spp., Phormia spp.), and Muscid flies. Other insects feed on the leaves, fruit, wood, or other parts of hawthorns (Crataegus spp.). The caterpillars of the butterfly Satyrium liparops strigosum (Striped Hairstreak) occasionally feeds on these shrubs, as do the caterpillars of many moth species (see Moth Table). Other insect feeders include leafhoppers (see Leafhopper Table), the Quince Treehopper (Glossonotus crataegi), aphids, plant bugs, the Hawthorn Lace Bug (Corythucha cydoniae), larvae of long-horned beetles, the flea beetle Crepidodera violacea, weevils, and larvae of gall flies (see Insect Table for a listing of these various species). While it is not a preferred source of food, several species of upland gamebirds and songbirds eat the fruit (see Bird Table), as do the Black Bear, Coyote, Gray Fox, Raccoon, Striped Skunk, Fox Squirrel, and Gray Squirrel. Cottontail Rabbits and White-Tailed Deer also browse on the leaves and twigs. Because of their dense branching patterns and thorns, hawthorns provide good nesting habitat for the Yellow-Breasted Chat, Brown Thrasher, Loggerhead Shrike, and other birds that like to construct nests in shrubs. The Loggerhead Shrike also uses the thorns to impale its prey. These shrubby trees also provide good protective cover for roosting birds and secretive mammals, particularly when they form colonies. Overall, the ecological value of hawthorns to wildlife is high.

Photographic Location: A woodland edge at Orchid Hill in Vermilion County, Illinois.

Comments: This is one of many hawthorn species in Illinois; across different populations, it is rather variable. As a group, hawthorns (Crataegus spp.) are difficult to identify; the number of species varies with the taxonomy. Several hawthorn species are regarded as identical to, or variants of, Waxy-Fruited Hawthorn. As a result, Crataegus gattingeri, Crataegus leiophylla, and Crataegus platycarpa, and several others are usually regarded as scientific synonyms of Crataegus pruinosa (Waxy-Fruited Hawthorn). Critical features for identification include flower size, the number of stamens, the color of anthers, the shape and hairiness of the leaves, terminal points of the lateral leaf veins, hairiness of the pedicels, length and curvature of the thorns, and characteristics of the fruit. Waxy-Fruited Hawthorn is somewhat unusual in lacking hairs on its leaves, young leafy shoots, and pedicels, while its flowers (with 20 stamens) are larger than average in size for species in this genus. Another common name of Crataegus pruinosa is Frosted Hawthorn.