Malus pumila
Rose family (Rosaceae)

Description: This small tree is typically 15-50' tall, forming a short crooked trunk about 1-2' across and a globoid crown with spreading crooked branches. Trunk bark is reddish gray, thin, and irregularly fissured, while branch bark is more gray and smooth. Twigs are reddish brown to brown with scattered white lenticels; they are glabrous or pubescent. Young shoots are light gray-green to purple, terete, and densely pubescent. Alternate leaves about 2-3" long and 1-2" across occur along the twigs and young shoots. The leaf blades are lanceolate-ovate to ovate in shape and finely serrated or crenulated along their margins. The upper surface of the leaf blades is yellowish green to dark green and hairless (or nearly so), while the lower surface is pale gray-green or whitish green and more or less downy from short fine hairs. The petioles are -1" long, whitish green to dull purple, and downy from short fine hairs. Bases of the leaf blades are rounded or slightly cordate, while their tips are blunt to pointed.

Relatively large flowers about 1-2" across are produced in small clusters from short spur twigs. Individual flowers have 5 rounded petals that are pinkish white to white and contracted at their bases, 5 lanceolate sepals that are pale gray-green and downy from short fine hairs, numerous stamens (about 20) with yellow anthers, and an inferior ovary with 5 styles. The sepals are much smaller than the petals. The slender pedicels are pale gray-green and downy from short fine hairs. The blooming period occurs during late spring for about 2 weeks (after the vernal leaves have unfolded). The flowers are fragrant. Fertile flowers are replaced by small green pomes that develop during the summer. At maturity during late summer or fall, the pomes are 1-4" across and more or less globoid in shape; each pome has a depression at its top and bottom. The exterior of mature pomes is usually greenish red or red (rarely yellow) and glabrous or nearly so; sometimes short fine hairs occur within the depressions of each pome. The fleshy interior of mature pomes is greenish white to pale yellow, crisp, and somewhat juicy; the flavor can be sour, sweet-sour, or sweet. Within the central portion of each pome, there are up to 10 brown seeds. These small seeds are ovoid and flattened. The deciduous leaves usually turn yellow during the autumn.

The preference is full sun, moist to mesic well-drained conditions, and fertile loamy soil. The cultivated Apple is vulnerable to many insect pests and disease organisms, although some cultivars have greater resistance to them than others. Dwarf cultivars are available that produce full-sized fruit on trees less than 10' tall.

Range & Habitat: As a naturalized tree, the non-native Apple is occasional in NE Illinois and uncommon elsewhere (see Distribution Map). It was introduced from Eurasia into North America. Habitats for naturalized trees include woodland borders, disturbed meadows, abandoned orchards and old homesteads, areas along roads, and fence rows. Apple is often cultivated for its large edible fruit and it is used as an ornamental landscape tree. When it escapes from cultivation, Apple is not aggressive and invasive. The fruits of escaped trees are usually smaller than those of cultivated trees. Apple is vulnerable to wildfires.

Faunal Associations:
The flowers must be cross-pollinated by insects from other compatible trees, otherwise Apple does not set fruit. Bees are the most important visitors of the flowers, where they seek nectar or pollen. Typical bee visitors include honeybees, bumblebees, Andrenid bees (Andrena spp.), long-horned bees (Synhalonia spp.), and mason bees (Osmia spp.). Other insects eat the foliage, suck plant juices, bore through the wood, or feed destructively on the fruit and flowers. The caterpillars of the following butterflies occasionally eat the leaves of Apple and other Malus spp.: Limenitis archippus (Viceroy), Limenitis arthemis astyanax (Red-Spotted Purple), Papilio glaucus (Tiger Swallowtail), and Satyrium liparops strigosum (Striped Hairstreak). The caterpillars of many moths also feed on these shrubs and small trees; they include such species as Choreutis pariana (Apple & Thorn Skeletonizer), Malacosoma americanum (Eastern Tent Caterpillar), Orthosia hibisci (Speckled Green Fruitworm), Phyllonorycter crataegella (Apple Blotch Leafminer), and Sphinx gordius (Gordian Sphinx). See the Moth Table for a more complete list of species. Larvae of the long-horned beetles Saperda candida (Round-Headed Apple Tree Borer) and Saperda cretata (Spotted Apple Tree Borer) bore through the wood of these trees, as do larvae of the Buprestid beetle Chrysobothris femorata (Flat-Headed Apple Tree Borer). Other insect feeders include Anthonomus quadrigibbus (Apple Curculio), Conotrachelus nenuphar (Plum Curculio), and Rhynchaenus pallicarnis (Apple Flea Weevil); Aphis pomi (Green Apple Aphid), Dysaphis plantaginea (Rosy Apple Aphid), Eriosoma lanigerum (Woolly Apple Aphid), and Rhopalosiphum insertum (Apple Grain Aphid); Typhlocyba pomaria (White Apple Leafhopper) and other leafhoppers; Ceresa bubalus (Buffalo Treehopper) and other treehoppers; Lygidea mendax (Apple Red Bug) and other plant bugs; Acrosternum hilaris (Green Stink Bug) and other stink bugs; and Rhagoletis pomenella (Apple Maggot). See the Insect Table for a more complete list of these species. In addition to these insects, another invertebrate feeder is Aculus schlechtendali (Apple Rust Mite).

Some vertebrate animals also use Apple trees as a food source. Their buds are eaten by the Ruffed Grouse, Purple Finch, and White-Throated Sparrow, while their fruits are eaten by the Black Bear, White-Tailed Deer, Red Fox, Opossum, Striped Skunk, and the introduced Monk Parakeet. The Cottontail Rabbit and Meadow Vole gnaw on the bark of saplings during the winter, occasionally girdling and killing them. White-Tailed Deer like to browse on the leaves and twigs of Apple trees, particularly those of smaller and more vulnerable trees. Mammals that eat the fruits can spread the seeds into new locations. Humans also spread the seeds when they throw apple cores out of car windows or toss them aside along paths in natural areas. Occasionally, the Apple and other Malus spp. provide nesting habitat for such birds as the Yellow-Breasted Chat, Song Sparrow, and Orchard Oriole.

Photographic Location: A small tree along a sidewalk in Urbana, Illinois.

This is the domesticated Apple tree that occasionally escapes from cultivation. In the published literature and on the internet, a confusing variety of scientific names refer to this tree: Malus communis, Malus domestica, Malus pumila, Malus sylvestris, and Pyrus malus. Of these, Malus pumila is the preferred scientific name for both cultivated and naturalized Apple trees. Because naturalized trees may hybridize with other Malus spp. (Crab Apples), identification of wild trees can be difficult, particularly around urban and suburban areas. In general, Apple has larger fruits (1" across or more) than Crab Apples. It also has leaves that are short-pubescent on their undersides and they lack lateral lobes. The native Crab Apples have smaller greenish yellow fruits and their leaves are often shallowly lobed. Another cultivated species that sometimes escapes, Malus baccata (Siberian Crab Apple), also has smaller fruits and its leaf undersides are hairless.