The Buckeyes & Horsechestnut: genus Aesculus

Scientific Name: Aesculus hippocastanum (EE·skew·luss HIP·po·CAST·uh·numb) from Greek hippo "horse" and Latin castanum "chestnut"
Common Name: Horsechestnut
Family: Hippocastanaceae (HIPpo·CAST·uh·NAY·see·ee) the Buckeye family
Bark: Medium gray, patchy scales.
Buds: Brown, imbricate. Terminal bud 2 cm. long, sticky and glossy.
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Distribution:
Flowers: May and June. Perfect, zygomorphic, in upright clusters, showy, white with red in throat of tubular corolla.
Fruit: Green dehiscent husks with strong prickles. Fruit contains three roundish seeds 4 cm. in diameter brown, smooth, with tan hilum over 1 cm. in diameter.
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Leaves: Opposite, palmately compound, broadly oblanceolate, with acuminate tip.
Similar trees Leaves grossly resemble native Aesculus (buckeyes), prickly fruit is distinctive. Buckeyes have smooth fruits and leaflets are lanceolate, lighter, shinier.
Twigs: Upcurved, stout.
Remarks: Messy, rather coarse textured (from landscaper's point of view), but charming tree. Seeds are excellent for hucking at dogs and cars, or just collecting. Seeds collected in spring will germinate readily.

Scientific Name: Aesculus octandra
Common Name: yellow buckeye, sweet buckeye
Family: Hippocastanaceae
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The Tree-of-Heaven: genus Ailanthus
Scientific Name: Ailanthus altissima (ey-LAN-thuss al-TISS-sim-uh)
Common Name: Tree of Heaven
Family: Simaroubaceae (sigh·muh·roo·BAY·see·ee)
Bark: Smoothish, not very thick, medium grey, .
Buds: Small for size of leaf. Large leaf scars (10 mm long, 7 wide) have 11 or so vascular bundle scars, are dirty-white.
Distinctive Characteristics: Fruits; habit of sprouts from stump; leaves; bark, to a degree.
Distribution: A weed, more common in the city than suburbs. Almost never cultivated. Native to China.
Flowers: Whitish, almost showy, in panicles 8" long. Monoecious.
Fruit: Clusters of samaras (narrowed at ends, twisted in shape, with seed in middle) that are tinged beautifully russet in August to September. The fruits cling until November, and rustle in the wind.
Habit: A very vigorous, weedy tree. Often cut down, it makes prodigious growth from the roots, often growing more than 8' in a single year. The sprouts have enormous leaf scars, and are quite stout.
Habitat: Vacant lots, front yards of indifferent land owners, cracks between sidewalk and buildings. Almost never planted. Tolerates city conditions better than any other tree in area.
Leaves: Alternate, pinnately compound. The leaflets have a pair of blunt teeth near the base, with glands on the underside of the teeth. Crushed leaves often smell bad. Length 45-65 cm, leaflets 8-13 cm, 20 or more per leaf.
Similar trees Staghorn Sumac, Rhus typhina has superficially similar leaves.
Twigs: Very stout. Upcurved. Rusty grey, with fine down. Smooth, scattered glands are brown.
The Silk Tree: genus Albizia
Scientific Name: Albizia julibrissin
Common Name: silktree, albizia, mimosa
Family: Mimosaceae (mim·o·ZAY·see·ee) the Mimosa family
Bark: horizontal lenticels
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Distribution: Not a very commonly planted tree. There is one to the north of Weld Hall in Harvard Yard.
Flowers: Pinkish clusters, August.
Fruit: A pale colored pod 10-12 cm. long.
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Habitat: Only in cultivation.
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The Alders: genus Alnus

Scientific Name: Alnus glutinosa
Common Name:European alder
Family: Betulaceae /bet·you·LAY·see·ee/
Bark: Medium grey, smoothish, with short horizontal pale lenticels.
Buds: Reddish-brown, stalked, naked, to 1 cm.
Distinctive Characteristics: Fruit.
Distribution: A European tree, escaped from cultivation. Often numerous along a given river bank.
Flowers: Brown catkins in spring.
Fruit: Like little woody cones, green then turning dark brown, with scales separating. 16 mm. long, 10 mm wide. Peduncle 1 cm. Often quite abundant.
Habit: Small to smallish tree, less than 10 m. high.
Habitat: River banks.
Leaves: Obovate, twice serrate, with concave or notched tip. 4-5 cm. wide, 5-6 cm. long. Straight, parallel veins.
Similar trees Other alders.
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Scientific Name: Alnus rugosa
Common Name: Speckled Alder
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Scientific Name: Alnus serrulata
Common Name:Smooth Alder
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The Juneberries: genus Amelanchier
The genus Amelanchier is fairly easy to identify. The alternate, elliptical, singly-serrate leaves 3-5 cm long, the smooth light grey bark, and shrubby habit are fairly distinctive.

Scientific Name: Amelanchier
Common Name: juneberry, serviceberry
Family: Rosaceae (roe·ZAY·see·ee) the Rose family
Bark: Light grey, smooth, with wavy lines running vertically up the trunk.
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Distinctive Characteristics: The smooth vertically striated light gray bark.
Distribution:
Flowers: Small white, 5 petals and 5 sepals.
Fruit: 8 mm in diameter, bright red.
Habit:A large shrub.
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Leaves: Elliptical, serrate, simple.
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The Birches: genus Betula


Scientific Name: Betula populifolia (BET·yew·luh POP·yew·lif·FOH·lee·uh) "poplar-leaved birch"
Common Name: Gray Birch.
Family: Betulaceae (BET-yew-LAY-see-ee)
Bark: Chalky white on mature trees, with black upside down vees beneath branches. Glossy and reddish when young, with horizontal lenticels. Does not peel. Dead trees often bear tan toadstools, with creamy undersides.
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Distinctive Characteristics: Leaf, bark (be careful of B. papyrifera and B. pendula).
Distribution: Native, widespread. Although not a landscaper's choice, it occurs regularly on suburban lawns.
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Habit: A small, short-lived tree. Often in clumps. Slender branches, leaning trunk.
Habitat: Sunny woods, old fields. Sometimes in waste places.
Leaves: Alternate, serrate. Glossy green above, with blunt base and long tip. Not at all poplar-like.
Similar trees Paper Birch and European White Birch strongly resemble this tree, but have larger, rounder leaves, thinner creamier bark that peels.
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Scientific Name: Betula lenta (BET·you·luh LENT·uh) "slow birch"
Common Name: Black Birch, Sweet Birch
Family: Betulaceae (BET·yew·LAY·see·ee)
Bark: Almost black when mature, with thick scales. Young bark is redder, glossy, with horizontal lenticels.
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Distinctive Characteristics: Twigs.
Distribution: All over the place. Native.
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Habit: A good-sized tree, fairly vertical, with smallish limbs.
Habitat: Woods. Not commonly cultivated.
Leaves: Alternate, serrate, elliptical, pubescent. Handsome yellow fall color, rivalling Red Maple.
Similar trees Trunk looks like a Black Cherry's. Distinguish the two by their twigs' different tastes.
Twigs: Slender, dark brown, with distinct wintergreen taste when chewed.
Paper Mulberry: genus Broussonetia

Copyright © 1989, 1997, 2013 Brian Laurence Hughes
Last modified: 2013 Jan 01 at 08:12 EST

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