eath, or minutely pubescent on the veins
=Sugar Maple, Acer saccharum.=

5b. Leaves downy beneath =Black Maple, Acer saccharum var. nigrum.=

6a. Middle leaf-lobe usually more than half the length of the leaf,
narrowed at its base; broken twigs with a strong odor
=Silver Maple, Acer saccharinum.=

6b. Middle leaf-lobe usually less than half the length of the leaf,
its sides parallel or broadened at the base; broken twigs
without strong odor =Red Maple, Acer rubrum.=

SAPINDACEAE, the Soapberry Family

Trees, with opposite palmately compound leaves, and showy white or
yellowish flowers in panicles in spring; sepals 5; petals 4 or 5;
stamens about 7; fruit a smooth brown nut.

1a. Leaflets 7; buds viscid; corolla of 5 petals
=Horse Chestnut, Aesculus hippocastanum.=

1b. Leaflets 5; buds smooth; corolla of 4 petals
=Buckeye, Aesculus glabra.=

BALSAMINACEAE, the Touch-me-not Family

Smooth herbs, with alternate simple leaves and showy flowers; one
petal-like sepal prolonged into a spur; fruit explosive when ripe (5-10
dm. high; summer).

1a. Flowers pale-yellow, with a few red-brown spots
=Touch-me-not, Impatiens pallida.=

1b. Flowers orange, thickly spotted with red-brown
=Touch-me-not, Impatiens biflora.=

RHAMNACEAE, the Buckthorn Family

Shrubs, with simple leaves and small flowers in axillary or terminal
clusters in early summer; sepals, petals, and stamens each 4 to 5, or
petals none.

1a. Leaves with a single mid-vein; flowers in axillary clusters,
greenish (Buckthorn) --2.

1b. Leaves with 3-5 principal veins; flowers in dense terminal clusters,
white (Red-root) --3.

2a. Lateral veins 3-4 pairs (stout shrub, frequently thorny,
escaped from cultivation) =Buckthorn, Rhamnus cathartica.=

2b. Lateral veins 6-9 pairs (1 m. high or less; in swamps and bogs)
=Buckthorn, Rhamnus alnifolia.=

3a. Leaves ovate, rounded or cordate at the base, 2-5 cm. wide or more
(4-8 dm. high) =Red-root, Ceanothus americanus.=

3b. Leaves elliptical-lanceolate, 2 cm. wide or less (3-8 dm. high)