Monday, May 17, 2010

Sophora japonica - Japanese Pagoda Tree

also known as Chinese Scholar Tree

Seed pods (legumes) resemble a string of pearls.

Sunday, May 16, 2010

Robinia x ambigua 'Purple Robe' - Purple Robe Locust

Patented hybrid between Robinia ambigua 'Decaisneana' and R. hispida 'Monument.'

Pinnately compound leaves with ovate to oblong leaflets. Mostly thornless, but there are rounded thorn nubs at leaf nodes.

Purple flowers are mostly scentless, but a deep whiff with your nose buried in the blossoms can yield a faint rose scent.

Reddish brown to gray bark develops fissures and cracks. Wood is brittle and limbs tend to break on older trees.

Melia azedarach - China-Berry

Saturday, May 15, 2010

Gleditsia triacanthos inermis - Thornless Honey Locust

Cultivar 'Sunburst' has yellow foliage.

Leaves pinnately or bipinnately compound.

Friday, May 14, 2010

Crataegus phaenopyrum - Washington Thorn

Watch out for long thorns.

Celtis sinensis - Chinese Hackberry

Medium textured tree with leathery leaves.

Distal 1/3 of leaf margins are crenate to serrate with entire margins about the leaf base. Leaf base is oblique, as is typical of the Elm family (Ulmaceae).

Smooth grayish brown bark takes on blackish margins and warty growths with age, often with shallow furrows and ridges.

Thursday, May 13, 2010

Catalpa speciosa - Western Catalpa

Very coarse textured tree, often with a broad, round headed canopy at maturity. This species is taller than C. bignonioides.

Huge (6-12") cordate leaves.

Creamy white campanulate (bell-shaped) flowers with yellow and brown/purple markings. Inflorescences are smaller than in C. bignonioides.

Showy seed capsules resemble vanilla beans. Capsules are larger than in C. bignonioides.

Bark is thin grayish brown, becoing fissured with flat scaly ridges.

Albizia julibrissin - Silk Tree

See also this video of the leaves displaying thigmonasty (touch-induced movement).

Wednesday, May 12, 2010

Aesculus x carnea - Red Horeschestnut

Round-headed, coarse textured tree.

Palmately compound leaves (8-12" across) appear puckered or crinkly.

Showy upright panicles (8-10" long) of pink to dark red flowers. Fruits are a prickly capsule, similar to chestnuts.

Smooth to shallowly fissured and scaly white to grey to brown bark

Quercus robur - English Oak

Broad, irregular canopy with heavy, upward reaching limbs and small twiggy branchlets.

Lobed, oval leaves with a short petiole, if any.

Male flowers.

Dark brown oval acorns with flattened rounded ends and a blunt nib mature in fall. Warty cup scales cover up to one half of the nut.

Dark brown furrowed bark with flat peeling ridge plates.

Quercus palustris - Pin Oak

Moderately fast growing tree with a pyramidal form, often with upper branches reaching up, middle branches reaching horizontally, and lower branches swooping downward.

Simple leaves up to 10" long are 5-7 lobed with rounded sinuses and pointed pin-like protrusions at the tips.

Wide acorns with a shallow cup mature in the fall of the second season.

Smooth grayish brown bark with shallow vertical furrows.