À. circinàtum.
12. Àcer circinàtum, Pursh. (Round-leaved or Vine Maple.) Leaves orbicular, with 7 to 11 serrated, acute lobes, a heart-shaped base, reddish-green color, and both surfaces smooth. Corymbs of purplish flowers, small and hanging on long peduncles; appearing after the leaves. Wings of the fruit diverging in a straight line. A small tree or tall shrub, 10 to 30 ft. high, of spreading habit, with smooth bark, and pale brown twigs; cultivated; from the Pacific coast of North America.
À. Tartáricum.
13. Àcer Tartáricum, L. (Tartarian Maple.) Leaves ovate, slightly cordate, rarely lobed, serrated, light-colored, expanding very early in the spring. Panicle of greenish-yellow flowers erect, blooming after the leaves have expanded. Wings of the fruit parallel or sometimes touching. A small tree, sometimes shrubby in growth, of irregular form, with brown twigs; rarely cultivated; from Europe.
Genus 26. NEGÚNDO.
Leaves pinnate, of 3 to 5 leaflets. Flowers rather inconspicuous. Fruit a two-winged key as in Acer, in drooping racemes.
N. aceroìdes.
Negúndo aceroìdes, Moench. (Ash-leaved Maple. Box-elder.) Leaves pinnate, of 3 to 5 (rarely 7) coarsely and sparingly toothed leaflets. Flowers staminate and pistillate on separate trees, in drooping clusters rather earlier than the leaves. Fruit on only a portion of the trees; wings forming less than a right angle. A rather small (30 to 60 ft. high), rapidly growing tree, with light pea-green twigs; wild from Pennsylvania and south, and cultivated throughout.