=Squashberry, Viburnum pauciflorum.=

25a. Outer flowers of the cluster enlarged and imperfect (1-3 m. high)
=Hobble-bush, Viburnum alnifolium.=

25b. All flowers of the cluster alike --26.

26a. Leaves finely serrate; the veins not prominent --27.

26b. Leaves coarsely serrate, all or most of the teeth terminating
in a prominent vein --29.

27a. Peduncle of the flower-cluster, below its branches, at least 2 cm.
long (1-3 m. high) =Withe-rod, Viburnum cassinoides.=

27b. Peduncle of the cluster 1 cm. long, or even shorter (3-8 m. high)
--28.

28a. Leaves distinctly acuminate =Sheep-berry, Viburnum lentago.=

28b. Leaves obtuse or barely acute
=Black Haw, Viburnum prunifolium.=

29a. Leaves densely pubescent beneath (6-15 dm. high)
=Arrow-wood, Viburnum pubescens.=

29b. Leaves glabrous beneath, or with tufts of hairs in the forks of the
veins (1-4 m. high) =Arrow-wood, Viburnum dentatum.=

VALERIANACEAE, the Valerian Family

Herbs with opposite leaves and small nearly or quite regular flowers;
petals 5, united; stamens 3; sepals minute or wanting; ovary inferior.

1a. Stem-leaves pinnately cleft (3-10 dm. high; flowers white or
pinkish, summer) --2.

1b. Stem-leaves entire or dentate (2-6 dm. high; flowers white, summer)
(Corn Salad) --3.

2a. Leaf-segments parallel-veined Valerian, Valeriana edulis.

2b. Leaf-segments net-veined
=Swamp Valerian, Valeriana uliginosa.=

3a. Upper stem-leaves entire
=Corn Salad, Valerianella chenopodifolia.=

3b. Upper stem-leaves dentate =Corn Salad, Valerianella radiata.=

DIPSACACEAE, the Teasel Family

Herbs with opposite leaves, and small pale blue flowers aggregated in
dense heads; calyx minute; petals 4, united; stamens 4, attached to the
corolla; ovary inferior.

One species in Michigan, 1-2 m. high, with prickly leaves and stem,
blooming in summer =Teasel, Dipsacus sylvestris.=

CUCURBITACEAE, the Gourd Family

Herbs, climbing by tendrils, with alternate palmately lobed leaves and
imperfect flowers; staminate flowers in showy clusters, with 5-6 petals
and 3 stamens; pistillate flowers small.

1a. Leaves 5-ang