10b. Petiole slender, about 10-20 mm. long =Peach-leaved Willow, Salix amygdaloides.=

11a. Leaves green beneath =Crack Willow, Salix fragilis.=

11b. Leaves pale beneath --12.

12a. Branches and twigs conspicuously drooping =Weeping Willow, Salix babylonica.=

12b. Branches and twigs not conspicuously drooping, yellow =Yellow Willow, Salix alba var. vitellina.=

13a. Shrubs of bogs --14.

13b. Plants of sand-dunes along the Great Lakes --15.

13c. Plants of dry upland hills --16.

13d. Plants of wet ground, river-banks, and swamps --17.

14a. Leaves densely white-tomentose beneath =Willow, Salix candida.=

14b. Leaves pale beneath but not tomentose =Willow, Salix serissima.=

14c. Leaves glabrous and green beneath =Willow, Salix pedicellaris.=

15a. Leaves linear =Willow, Salix longifolia.=

15b. Leaves ovate-lanceolate, tomentose beneath =Willow, Salix syrticola.=

15c. Leaves ovate-lanceolate, glabrous =Willow, Salix glaucophylla.=

16a. Leaves about 3 times as long as broad =Willow, Salix rostrata.=

16b. Leaves narrower, nearly sessile =Willow, Salix tristis.=

16c. Leaves narrower, distinctly petioled =Willow, Salix humilis.=

17a. Leaves linear or nearly so =Willow, Salix longifolia.=

17b. Leaves shining =Willow, Salix lucida.=

17c. Leaves silky =Willow, Salix sericea.=

17d. Leaves not as in the preceding 3 species --18.

18a. Leaves rounded at base =Willow, Salix cordata.=

18b. Leaves acute at base --19.

19a. Leaves finely serrulate =Willow, Salix petiolaris.=

19b. Leaves remotely serrate or nearly entire =Willow, Salix discolor.=

MYRICACEAE, the Sweet Gale Family

Shrubs, with monoecious or dioecious flowers in catkins, and aromatic foliage.

1a. Leaves pinnately lobed =Sweet Fern, Myrica asplenifolia.=

1b. Leaves merely serrate --2.

2a. Shrub of sandy soil, sh.o.r.e of Lake Erie =Bayberry, Myrica carolinensis.=

2b. Shrub of bogs and sh.o.r.es, northern half of state =Sweet Gale, Myrica gale.=

JUGLANDACEAE, the Walnut Family

Trees with alternate pinnately compound leaves and flowers in catkins.

1a. Leaflets 11-23; pith divided by part.i.tions into chambers --2.

1b. Leaflets 5-11; pith not part.i.tioned (Hickory) --3.

2a. Pith brown; bark with flat longitudinal ridges =b.u.t.ternut, Juglans cinerea.=

2b. Pith cream-color; bark of trunk without flat ridges =Black Walnut, Juglans nigra.=

3a. Bark of the trunk essentially smooth, not deeply furrowed or s.h.a.ggy --4.

3b. Bark of the trunk deeply furrowed or s.h.a.ggy --6.

4a. Leaflets glabrous beneath; buds greenish --5.

4b. Leaflets somewhat p.u.b.escent beneath; buds bright yellow =Bitter Nut, Carya cordiformis.=

5a. Twigs hairy =Small-fruited Hickory, Carya microcarpa.=

5b. Twigs smooth =Pignut Hickory, Carya glabra.=

6a. Twigs and leaves both p.u.b.escent --7.

6b. Twigs nearly smooth; leaves smooth beneath =s.h.a.g-bark Hickory, Carya ovata.=