The Plants of Michigan Part 60

3b. Leaves coa.r.s.ely and bluntly serrate; young twigs p.u.b.escent; bark not striped =Mountain Maple, Acer spicatum.=

4a. Angles between the leaf-lobes rounded (flowers greenish-yellow, appearing with the leaves) --5.

4b. Angles between the leaf-lobes acute or obtuse, but not rounded (flowers purple, red, or yellowish, appearing before the leaves) --6.

5a. Leaves glabrous beneath, or minutely p.u.b.escent 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 cl.u.s.ters in early summer; sepals, petals, and stamens each 4 to 5, or petals none.

1a. Leaves with a single mid-vein; flowers in axillary cl.u.s.ters, greenish (Buckthorn) --2.

1b. Leaves with 3-5 princ.i.p.al veins; flowers in dense terminal cl.u.s.ters, white (Red-root) --3.

2a. Lateral veins 3-4 pairs (stout shrub, frequently th.o.r.n.y, 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 america.n.u.s.=

3b. Leaves elliptical-lanceolate, 2 cm. wide or less (3-8 dm. high) =Red-root, Ceanothus ovatus.=

VITACEAE, the Grape Family

Shrubs, climbing by tendrils or hold-fast roots, with palmately lobed or palmately compound leaves and small greenish flowers in panicles or flattened cl.u.s.ters; petals and sepals each 4 or 5; fruit a berry.

1a. Leaves compound (summer) (Virginia Creeper) --2.

1b. Leaves simple (late spring) (Grape) --4.

2a. Branches of the tendrils chiefly ending in adhesive disks --3.

2b. Branches of the tendrils twining, or rarely with a few disks =Virginia Creeper, Psedera vitacea.=

3a. Stem and foliage glabrous =Virginia Creeper, Psedera quinquefolia.=

3b. Stem and foliage p.u.b.escent, at least when young =Virginia Creeper, Psedera quinquefolia var. hirsuta.=

4a. Leaves conspicuously p.u.b.escent beneath --5.

4b. Leaves glabrous beneath when mature, or p.u.b.escent on the veins only --6.

5a. A tendril or flower-cl.u.s.ter opposite each leaf =Fox Grape, Vitis labrusca.=

5b. No tendril opposite each third leaf =Summer Grape, Vitis aestivalis.=

6a. Pith continuous through the joints of the stem =Fox Grape, Vitis rotundifolia.=

6b. Pith interrupted by the solid joints --7.

7a. Leaf-lobes with rounded angles between them =Summer Grape, Vitis bicolor.=

7b. Leaf-lobes with sharp angles between them --8.

8a. Leaves coa.r.s.ely toothed, unlobed or slightly 3-lobed =Frost Grape, Vitis cordifolia.=

8b. Leaves sharply toothed, prominently lobed =Frost Grape, Vitis vulpina.=