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.

Albizia julibrissin - Silk Tree

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

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.

Chamaecyparis obtusa - Hinoki Cypress

Chamaecyparis obtusa: Chamaecyparis from Greek chamai, meaning 'dwarf', and kuparissos, meaning 'cypress'; obtusa, meaning 'blunt', possibly referring to the leaf tip.

Slow growing formal pyramidal tree will stay small for many years.
Flat sprays of scale-like leaves, often in horizontal tiers.
1/4" female cones produced in fall. 'Aurea' cultivar has yellow new growth in the sun.
Reddish brown bark sheds in long narrow strips.
Often seen as a bonsai specimen.

Diospyros kaki - Japanese Persimmon

Diospyros kaki: Diospyros from Greek dios meaning 'divine' and pyros meaning 'wheat', so named for this tree's edible fruit; kaki from the Japanese name for this plant kaki-no-ki.

Upright, often wide-spreading habit
Somewhat large ovate leaves lend a coarse texture.
Small (3/4") white to yellow flowers. The calyx will harden into a brown 'wood rose' as seen on top of the fruit.
Bright orange fruit is the persimmon of commerce. Hachiya variety is pictured.
Exellent yellow-orange-red fall color.
Fruit persists after leaf drop in fall.
Gray bark is furrowed and checkered.

Ficus carica - Common Fig

Ficus carica: Ficus, Latin name for this species, the edible fig; carica refers to Caria, an area in Asia Minor (in what is now Turkey), where many figs were cultivated in ancient times.

Trees are often multi-trunked, but can be pruned to standard.
Palmately lobed leaves.
Flowers form inside fruit, and are pollinated by a burrowing wasp.
Fruit forms on old and new wood, producing two crops a year in summer and fall.
Fruit is the edible fig of commerce.

Pinus densiflora - Japanese Red Pine

Pinus densiflora: Pinus, from Latin for 'pine'; densiflora, densely flowered -- possibly so named for its proliferation of cones.

Common in a multi-trunk form.
Needles in fascicles of two. Trees are monoecious.
'Oculus Draconis' cultivar has two yellow bands on each needle.
Flakey bark can resemble Ulmus Parvifolia.

Malus floribunda - Japanese Flowering Crabapple

Malus floribunda: Malus, from Greek melon, meaning apple; floribunda, producing abundant flowers.