36a. Flower-stalk without bracts below the raceme; flowers yellowish-green =Rein Orchis, Habenaria hookeri.=

36b. Flower-stalk bearing bracts below the raceme; flowers greenish-white --37.

37a. Spur 15-25 mm. long =Rein Orchis, Habenaria orbiculata.=

37b. Spur 30-50 mm. long =Rein Orchis, Habenaria macrophylla.=

38a. Lip fringed (Fringed Orchis) --43.

38b. Lip not fringed (Rein Orchis) --39.

39a. Lip with 2-3 evident teeth at apex --40.

39b. Lip without apical teeth --41.

40a. Stem-leaves 3 or more =Rein Orchis, Habenaria bracteata.=

40b. Stem-leaves 2 --35b.

41a. Flowers white =Rein Orchis, Habenaria dilatata.=

41b. Flowers greenish-yellow --42.

42a. Lip lanceolate, tapering toward the apex =Rein Orchis, Habenaria hyperborea.=

42b. Lip oblong, truncate at the apex =Rein Orchis, Habenaria flava.=

43a. Lip deeply 3-lobed, toothed or fringed --44.

43b. Lip not 3-lobed, but deeply fringed --46.

44a. Flowers purple =Purple Fringed Orchis, Habenaria psycodes.=

44b. Flowers white or nearly so --45.

45a. Spur 3 cm. long or more =Prairie Fringed Orchis, Habenaria leucophaea.=

45b. Spur 1-1.5 cm. long =Ragged Fringed Orchis, Habenaria lacera.=

46a. Flowers yellow =Yellow Fringed Orchis, Habenaria ciliaris.=

46b. Flowers white =White Fringed Orchis, Habenaria blephariglottis.=

PIPERACEAE, the Pepper Family

Herbaceous plants with alternate leaves, and flowers without either calyx or corolla.

One species in Michigan, a marsh plant with heart-shape leaves and slender racemes of white flowers =Lizard's Tail, Saururus cernuus.=

SALICACEAE, the Willow Family

Trees or shrubs, with dioecious flowers in catkins.

1a. Leaves less than twice as long as broad, on petioles 3 cm. long or more --2.

1b. Leaves more than twice as long as broad, on petioles 2.5 cm. long or less. (The genus Salix, or Willow, contains about 30 species in Michigan, of which only the commoner are mentioned here. For the others the Manuals should be consulted.) --8.

2a. Petioles strongly flattened laterally --3.

2b. Petioles not flattened laterally --6.

3a. Leaves broadly ovate or nearly circular --4.

3b. Leaves broadly triangular or deltoid in shape --5.

4a. Leaves coa.r.s.ely toothed =Large-toothed Aspen, Populus grandidentata.=

4b. Leaves finely crenulate or serrate =Quaking Aspen, Populus tremuloides.=

5a. Tree with narrow spire-shape crown =Lombardy Poplar, Populus nigra var. italica.=

5b. Tree with spreading crown =Cottonwood, Populus deltoides.=

6a. Lower side of leaf densely tomentose =White Poplar, Populus alba.=

6b. Lower side of leaf glabrous or nearly so --7.

7a. Petioles glabrous =Balsam Poplar, Populus balsamifera.=

7b. Petioles ciliate =Balm of Gilead, Populus candicans.=

8a. Trees --9.

8b. Shrubs --13.

9a. Petioles without glands --10.

9b. Petioles with glands --11.

10a. Petiole short (about 5 mm.), broad and flat =Black Willow, Salix nigra.=