Sapindaceae s.l. (Aceraceae) - maple! family Acer saccharinum silver maple Sight ID characteristics Vegetative Features: • Leaf: 4-6" long, simple, opposite, deciduous, deeply, palmately 5-lobed – light green above and silvery below. • Twig: lustrous with small lenticels, buds usually blunt, leaf scars V-shaped, 3 bundle scars unpleasant odor when crushed; buds reddish brown, large scales, flower buds often in conspicuous dense clusters. • Bark: smooth and gray on young trees but develops distinctive loosely attached scales on older trees. Often distinctive vase-shape – forking/y-shaped trunk. Reproductive Features: • Polygamous (mixture of perfect and imperfect flowers) with reduced perianth, emerging very early in the spring before the leaves. • Fruit a samaroid schizocarp, mericarp wings slightly divergent, 1 1/2 - 2 1/2" long.

69 NOTES AND SKETCHES

70 Sapindaceae s.l. (Aceraceae )- maple! family Acer rubrum red maple Sight ID characteristics Vegetative Features: • Leaf: 2 1/2-4" long, simple, opposite, deciduous, palmately 3-5-lobed with serrate margins, sinuses at right angles, light green above, pale and glaucous below. • Twig: lustrous with small lenticels, buds usually blunt, green or reddish (fall and winter) with several loose scales, leaf scars V-shaped, 3 bundle scars. • Bark: smooth and gray on young trees but breaks into scaly plates on older trees. Reproductive Features: • Polygamous with reduced perianth, emerging very early in the spring before the leaves. • Fruit a samaroid schizocarp, mericarp wings slightly divergent approximately 3/4" long.

71 NOTES AND SKETCHES

72 Sapindaceae s.l. (Aceraceae) - maple! family Acer saccharum sugar maple Sight ID characteristics Vegetative Features: • Leaf: 3 1/2-5 1/2" long, simple, opposite, deciduous, palmately 5-lobed, margin entire or nearly so, sinuses acute angles and rounded, apex acuminate, base cordate, bright green above and pale below with both surfaces glabrous, base of petiole red in spring. • Twig: brown, slender and shiny with lighter lenticels; terminal buds brown, very sharp pointed, with tight scales. • Bark: gray and deeply furrowed on older trees. Reproductive Features: • Polygamous, yellow, long pubescent pedicels, emerge with the leaves. • Fruit a samaroid schizocarp, mericarp wings 1-1 1/4" long and parallel to slightly divergent.

73 NOTES AND SKETCHES

74 Sapindaceae s.l. (Aceraceae) - maple! family Acer negundo box-elder Sight ID characteristics Vegetative Features: • Leaf: opposite, deciduous, pinnately or ternately compound, 3-7 leaflets are short-petioled, variably toothed. • Twig: green to purplish green, moderately stout, leaf scars narrow, often glaucous; buds white and hairy. • Bark: thin, gray to light brown, with shallow interlacing ridges. Reproductive Features: • Dioecious, flowers, apetalous and yellow-green, emerging with or before the leaves. • Fruit a samaroid schizocarp, 1 1/2 inches long, in drooping clusters, light tan in fall, persist throughout winter.

75 NOTES AND SKETCHES

76 Sapindaceae s.l. (Aceraceae) - maple! family Acer macropyhllum bigleaf maple Sight ID characteristics Vegetative Features: • Leaf: simple, opposite, deciduous, 6-10" long, palmately 5- lobed, bright green above paler below, petioles with milky sap, • Twig: stout, smooth, terminal bud large, with 3 or 4 greenish red scales. • Bark: light gray-brown and smooth on younger trees, becomes furrowed on older trees. Reproductive Features: • Polygamous, flowers are yellow-green, showy with perianth, borne in puberulent racemes. • Fruit a samaroid schizocarp, mericarp wings are 1-1 1/2" long and densely pubescent.

77 NOTES AND SKETCHES

78 Sapindaceae s.l. (Aceraceae) - maple! family Acer glabrum rocky mountain maple Sight ID characteristics Vegetative Features: • Leaf: opposite, deciduous, variable, usually 3-5-lobed, but often pinnately compound with 3 leaflets in the S. Rockies, bright green above, whitish below. • Twig: slender, pale green to red, buds red and pointed. • Bark: thin, tight, smooth and gray. Reproductive Features: • Polygamous, small yellow flowers, 4 sepals, 4 petals, emerging with leaves. • Fruit a samaroid schizocarp, mericarp wings moderately divergent, 3/4-1" long.

79 NOTES AND SKETCHES

80 Sapindaceae s.l. (Aceraceae) - CULTIVATED maple! family ornamental Acer platanoides escaped Norway maple naturalized Sight ID characteristics Vegetative Features: • Leaf: simple, opposite, deciduous, 4-7" long, 5-lobed with acuminate apex with a very pinched sharp tip, acute angled and rounded sinuses (similar to Acer saccharum, light green above and paler below. • Twig: stout, brown with a large, green to purple terminal bud, large bud scales. • Bark: dark gray-brown, tightly furrowed into narrow ridges on mature trees. Reproductive Features: • Usually dioecious, yellowish green flowers emerge before leaves. • Fruit a samaroid schizocarp, mericarps widely divergent, 1 1/2-2" long.

81 NOTES AND SKETCHES

82 Sapindaceae s.l. CULTIVATED (Hippocastanaceae)! ornamental Aesculus hippocastanum horsechestnut Sight ID characteristics Vegetative Features: • Leaf: opposite, deciduous, palmately compound, 7 obovate (occasionally 5) leaflets. • Twig: stout, leaf scar large, shield-shaped; terminal bud large (1/2 - 1”); shiny, sticky, reddish brown. • Bark: gray-brown and loosely scaled on mature trees. Reproductive Features: • Flowers showy and perfect, white with pink or yellow blotches on petals. Arranged in erect panicles. • Fruit is a large leathery and moderately spiny capsule that contains a single hard brown, smooth seed • Seed poisonous.

83 NOTES AND SKETCHES

84 Simaroubaceae – tree-of-heaven CULTIVATED family! escaped Ailanthus altissima naturalized tree-of-heaven invasive Sight ID characteristics Vegetative Features: • Leaf: alternate and deciduous, pinnately compound with 11-41 ovate-lanceolate leaflets, 1-2' long, leaflets 3-5" long with 1-5 basal teeth with gland below. • Twig: stout and pithy, very weak; large, shield shaped leaf scars. • Bark: gray-brown and smooth on young trees, becomes fissured on older trees. Reproductive Features: • Dioecious, flowers small and inconspicuous, yellowish in terminal clusters. • Fruits are twisted samaras with seed in the middle; borne in terminal clusters and often remaining on the tree over winter.

85 NOTES AND SKETCHES

86 Altingiaceae – sweet gum family Liquidambar! styraciflua sweetgum

Sight ID characteristics Vegetative Features: • Leaf: alternate, deciduous, palmately lobed, palmately veined, star-shaped, margins finely serrate. • Twig: shiny green to yellow-brown, often with corky outgrowths, terminal bud large, sticky, bud scales shiny, green to orange-brown. • Bark: Gray-brown, irregular furrows. Reproductive Features: • Monoecious, flowers imperfect, inconspicuous, arranged in globose heads. • Fruit a woody, 2-celled, beaked capsule arranged in globose heads.

87 NOTES AND SKETCHES

88