One species in Michigan, 1-3 dm. high; leaves less than 1 cm. long; flowers in summer =Crowberry, Empetrum nigrum.=

LIMNANTHACEAE, the False Mermaid Family

Low herbs with alternate compound leaves and minute axillary flowers; sepals 3, petals 3, stamens 6.

One species in Michigan, with stems 1-3 dm. long, and flowers in late spring =False Mermaid, Floerkea proserpinacoides.=

ANACARDIACEAE, the Cashew Family

Shrubs or small trees, with milky or resinous juice, alternate compound leaves sometimes poisonous to the touch, and small cl.u.s.tered greenish or yellowish flowers.

1a. Leaflets 7 to many (1-5 m. high) (Sumach) --2.

1b. Leaflets 3-5.

2a. Axis of the leaves wing-margined between the leaflets =Sumach, Rhus copallina.=

2b. Axis of the leaves not margined --3.

3a. Leaflets entire =Poison Sumach, Rhus vernix.=

3b. Leaflets serrate --4.

4a. Bark of the older stems glabrous =Sumach, Rhus glabra.=

4b. Bark of the older stems densely velvety-hairy =Sumach, Rhus typhina.=

5a. Terminal leaflet narrowed to a sessile base (5-20 dm. high) =Sumach, Rhus canadensis.=

5b. Terminal leaflet on a definite stalk, round or acute at base (3-8 dm. high, or climbing by hold-fast roots) =Poison Ivy, Rhus toxicodendron.=

AQUIFOLIACEAE, the Holly Family

Shrubs, with alternate simple leaves and small white or greenish axillary flowers in late spring and early summer; sepals, petals, and stamens each 4-6; fruit a berry.

1a. Leaves entire or nearly so, 1-3 cm. long (1-2 m. tall) =Mountain Holly, Nemopanthus mucronata.=

1b. Leaves sharply serrate, 5-8 cm. long (2-5 m. high) (Black Alder) --2.

2a. Leaves downy on the veins beneath; fruit red =Black Alder, Ilex verticillata.=

2b. Leaves nearly or quite glabrous; fruit orange =Black Alder, Ilex verticillata var. tenuifolia.=

CELASTRACEAE, the Staff Tree Family

Shrubs with simple leaves and inconspicuous flowers; sepals and petals each 4 or 5, the stamens of the same number and attached to a disk which fills the center of the flower; fruit showy, orange and red.

1a. Leaves alternate (climbing vine; flowers in racemes; late spring) =Bitter-sweet, Celastrus scandens.=

1b. Leaves opposite (flowers in axillary cl.u.s.ters) --2.

2a. Prostrate, with short erect branches; leaves broadest above the middle (spring) =Creeping Wahoo, Evonymus obovatus.=

2b. Tall shrub, with leaves broadest below or near the middle (early summer) =Wahoo, Evonymus atropurpureus.=

STAPHYLEACEAE, the Bladder Nut Family

Shrubs with opposite trifoliate leaves and small axillary cl.u.s.ters of white flowers in spring; sepals, petals, and stamens each 5; ovary 3-celled, ripening into a large inflated 3-celled pod.

One species in Michigan (2-5 m. high) =Bladder Nut, Staphylea trifolia.=

ACERACEAE, the Maple Family

Trees or shrubs, with opposite, lobed or compound leaves and inconspicuous flowers; sepals about 5; petals the same number, or none; stamens 4-12; ovary 2-lobed, ripening into a pair of winged fruits.

1a. Leaves compound (tree; flowers appearing before the leaves) =Box Elder, Acer negundo.=

1b. Leaves simple (Maple) --2.

2a. Shrubs or small trees; leaves 3-5-lobed; the lobes with regularly serrate margins (flowers greenish-yellow, appearing later than the leaves) --3.

2b. Trees; leaves 3-7-lobed; margins of the lobes entire or incised, but never regularly serrate --4.

3a. Leaves finely and sharply serrate; twigs smooth; bark conspicuously striped with white lines =Striped Maple, Acer pennsylvanic.u.m.=