Slippery elm

A dense, conical-to-narrow-pyramidal evergreen tree native to eastern and central North America, prized as a screening and foundation conifer. Flat, fan-like sprays of scale-like, aromatic yellow-green foliage clothe the tree from the ground up, and red-brown bark exfoliates on mature trunks. Wild trees can reach 40 to 60 feet but cultivated plants typically stay near 20 to 30 feet; small urn-shaped cones and dense evergreen cover make it valuable food and shelter for birds.

A medium-to-large native shade tree of central and eastern North America, reaching 50 to 80 feet with an ovate-rounded crown and large, asymmetric heart-shaped leaves. In June it carries pale-yellow, intensely fragrant flowers on pendulous cymes - each cluster hung from a distinctive strap-like leafy bract - that ripen into pea-sized nutlets. The fragrant June bloom is a premier nectar source: Missouri Botanical Garden lists it as attracting bees and butterflies, and the Lady Bird Johnson Wildflower Center flags it as having special value to both native and honey bees.

The only native U.S. holly with both spiny green leaves and bright red berries - an upright, pyramidal, broadleaf evergreen tree that slowly matures to 15 to 30 feet in cultivation (to 50 feet in the wild). Thick, leathery, deep green leaves bear spiny marginal teeth, and pollinated female trees carry showy red-to-orange drupes that ripen in fall and persist through winter as bird food. This is the classic "Christmas holly" of wreaths and decorations.

A small-to-medium understory tree of dry, rocky eastern-North-American woods, named for its drooping clusters of papery, sac-like seed pods that resemble the fruit of hops. The birch-like, sharply-serrated leaves turn an undistinguished yellow in fall, and reddish-brown male catkins persist on the bare branches through winter. Also called ironwood for its extremely hard, dense wood; tough, low-maintenance, and drought-tolerant once established.

A tough, medium-sized native tree of the eastern and midwestern United States, grown as much for its showy edible orange fruit as for its distinctive thick, dark gray bark broken into rectangular blocks. Small urn-shaped white-to-greenish-yellow flowers open in May and June, and the sweet fruit ripens after frost. Largely dioecious - a female tree needs a male pollinizer nearby to set fruit - and notably drought- and walnut-tolerant once established.

A small native deciduous tree (or thicket-forming, suckering shrub) of eastern and central North America, grown for clouds of fragrant white 5-petaled flowers that open in March before the leaves and for the edible red plums that follow in early summer. It forms a broad, spreading crown with attractive dark reddish-brown twigs that sometimes carry thorny lateral branchlets. A documented larval host for swallowtails and other butterflies, with flowers of special value to native, bumble, and honey bees.