Trees or tall shrubs with alternate, simple, pointed, 2-ranked, feather-veined, toothed leaves. Flowers inconspicuous, with the leaves in spring. Fruit a small, nut-like, scaly, globular drupe, ripe in autumn. Bark scaling off like that of the Sycamore.
P. aquática.
1. Plánera aquática, Gmel. (American Planer-tree.) Leaves ovate-oblong, small, 1 to 1½ in. long, on short stems, sharp-pointed, serrate with equal teeth, smooth, green above and gray below, not oblique at base. Flowers minute, in small heads, appearing before the leaves. Fruit a scaly, roughened nut, ¼ in., raised on a stalk in the calyx; ripe in September. A small tree, 20 to 50 ft. high; wet banks, Kentucky and southward; hardy as far north as Philadelphia.
P. acuminàta.
2. Plánera acuminàta. (Kiaka Elm or Japan Planer-tree.) Leaves large, glossy, smooth, deeply notched, on red stems; young shoots also red. This is a larger, more hardy, and finer tree than the American Planer-tree, and should be more extensively cultivated.
The Caucasian Planer-tree (Planera parvifolia), with very small leaves, is also occasionally cultivated.
Genus 76. CÉLTIS.
Trees or shrubs with alternate, simple, 2-ranked, oblique, serrate leaves. Flowers inconspicuous, greenish, axillary. Fruit berry-like, sweet, edible drupes, about the size of a currant, with one seed; color dark; ripe in autumn.