38a. Stem glabrous; leaves ovate to obovate (4-8 dm. high) =Downy Mint, Mentha gentilis.=

38b. Stem p.u.b.escent, at least on the angles (1-6 dm. high) --39.

39a. Princ.i.p.al leaves distinctly petioled and somewhat rounded at base =Wild Mint, Mentha arvensis.=

39b. Leaves tapering to the base --40.

40a. Leaves and stem p.u.b.escent =Wild Mint, Mentha arvensis var. canadensis.=

40b. Leaves glabrous; stem p.u.b.escent on the angles only =Wild Mint, Mentha arvensis var. glabrata.=

41a. Leaves linear; calyx-teeth awl-shape =Mountain Mint, Pycnanthemum flexuosum.=

41b. Leaves narrowly lanceolate; calyx-teeth triangular-ovate =Mountain Mint, Pycnanthemum virginianum.=

42a. Stems dec.u.mbent to diffuse; leaves cordate to nearly circular (stems 2-5 dm. long or high; flowers in spring and summer) (Dead Nettle) --43.

42b. Stem erect; leaves palmately cleft; calyx-teeth spiny (6-15 dm. tall; flowers pink, in summer) =Motherwort, Leonurus cardiaca.=

42c. Stems erect or ascending; leaves ovate-lanceolate to linear (summer) --45.

43a. Upper leaves closely sessile (flowers red-purple) =Dead Nettle, Lamium amplexicaule.=

43b. Leaves all petioled --44.

44a. Flowers red or purple =Dead Nettle, Lamium maculatum.=

44b. Flowers white =Dead Nettle, Lamium alb.u.m.=

45a. Flowers 2-2.5 cm. long, in loose terminal spikes (5-10 dm. tall; flowers rose-color) =False Dragon Head, Physostegia virginiana.=

45b. Flowers 1-2 cm. long, in axillary and terminal spiked whorls --46.

46a. Calyx-teeth spiny pointed (flowers pink or pale-purple) (Hemp Nettle) --47.

46b. Calyx-teeth acute to awl-shape, but not spiny (3-10 dm. high; flowers pale-purple) (Hedge Nettle) --48.

47a. Leaves ovate (3-8 dm. high) =Hemp Nettle, Galeopsis tetrahit.=

47b. Leaves linear to lanceolate (1-4 dm. high) =Hemp Nettle, Galeopsis ladanum.=

48a. Leaves glabrous --49.

48b. Leaves distinctly p.u.b.escent --50.

49a. Leaves ovate-lanceolate, serrate =Hedge Nettle, Stachys tenuifolia.=

49b. Leaves linear-oblong, entire or nearly so =Hedge Nettle, Stachys hyssopifolia.=

50a. Stem p.u.b.escent on the angles alone; leaves petioled =Hedge Nettle, Stachys tenuifolia var. aspera.=

50b. Stem p.u.b.escent on both sides and angles; leaves nearly sessile --51.

51a. Leaves oblong or oblong-lanceolate, more than 1 cm. wide =Hedge Nettle, Stachys pal.u.s.tris.=

51b. Leaves linear-lanceolate, 1 cm. wide or less =Hedge Nettle, Stachys arenicola.=

VERBENACEAE, the Verbena Family

Herbs, with simple opposite leaves and slightly irregular flowers in spikes or heads; petals 5, united and bearing the 4 stamens in the corolla-tube; ovary 1, 2-celled or 4-celled, with 1 style.

1a. Plants prostrate or spreading --2.

1b. Plants erect (flowers in summer) (Vervain) --3.

2a. Leaves serrate; flowers in short dense spikes (flowers pale-blue, summer) =Fog Fruit, Lippia lanceolata.=

2b. Leaves pinnatifid; flowers in loose bracted spikes (flowers light-purple, summer) =Vervain, Verbena bracteosa.=

3a. Spikes dense, continuous (flowers purple or blue, varying to white) --4.

3b. Spikes slender, interrupted, the flowers scattered (corolla white or pale-blue) --6.

4a. Leaves lanceolate, manifestly petioled (1-2 m. high) =Vervain, Verbena hastata.=

4b. Leaves sessile, not lanceolate (5-8 dm. high) --5.

5a. Leaves narrowly oblanceolate, tapering at the entire base =Vervain, Verbena angustifolia.=

5b. Leaves oblong to obovate, not tapering at the base =Vervain, Verbena stricta.=

6a. Leaves incised, tapering to a sessile base (5-10 dm. high) =Vervain, Verbena, officinalis.=

6b. Leaves serrate, petioled (1-2 m. high) =Vervain, Verbena urticaefolia.=

SOLANACEAE, the Nightshade Family

Herbs or shrubs, with alternate leaves and regular or slightly irregular flowers; sepals 5, united; corolla of 5 united petals, bearing the 5 stamens attached; ovary 1, 2-5 (usually 2)-celled, with a slender style.

1a. Corolla rotate; anthers close together (flowers in summer) --2.