6b. Leaves opposite (1-2 dm. high; summer) =Eyebright, Euphrasia arctica.=
7a. Stem-leaves entire (2-6 dm. high; summer) =Painted Cup, Castilleja pallida var. septentrionalis.=
7b. Stem-leaves palmately lobed, bracteal leaves scarlet (3-6 dm. high; early summer) =Painted Cup, Castilleja coccinea.=
7c. Stem-leaves pinnately lobed or incised (Lousewort) --8.
8a. Flowers in spring (2-4 dm. high) =Lousewort, Pedicularis canadensis.=
8b. Flowers in late summer (3-8 dm. high) =Lousewort, Pedicularis lanceolata.=
9a. Upper lip of the corolla very different in size and shape from the lower lip --10.
9b. Upper lip of the corolla resembling the lower lip in shape, and not very different in size (5-12 dm. high; summer) (False Foxglove) --13.
10a. Leaves alternate (2-5 dm. high; summer) =b.u.t.ter-and-eggs, Linaria vulgaris.=
10b. Leaves opposite --11.
11a. Stem erect; leaves narrowed at the base --30b.
11b. Stem creeping or spreading (summer) --12.
12a. Leaves pinnately veined, ovate =Musk Flower, Mimulus moschatus.=
12b. Leaves palmately veined, circular or nearly so =Yellow Monkey Flower, Mimulus glabratus var. jamesii.=
13a. Stem glabrous --14.
13b. Stem p.u.b.escent --15.
14a. Princ.i.p.al stem-leaves pinnatifid =False Foxglove, Gerardia virginica.=
14b. Princ.i.p.al stem-leaves entire =False Foxglove, Gerardia laevigata.=
15a. Corolla hairy on the outside =False Foxglove, Gerardia pedicularia.=
15b. Corolla smooth on the outside =False Foxglove, Gerardia flava.=
16a. Leaves all basal; flowers on leafless stalks (1 dm. high or less; flowers pink or white, summer) =Mudwort, Limosella aquatica var. tenuifolia.=
16b. Leaves opposite (those subtending the flowers may be alternate) --20.
16c. Leaves alternate or irregularly scattered --17.
17a. Leaves entire --18.
17b. Leaves pinnately lobed or incised --8a.
17c. Leaves palmately veined and lobed; stem trailing (flowers blue, summer) =Kenilworth Ivy, Linaria cymbalaria.=
18a. Corolla-tube less than 1 cm. long, spurred --19.
18b. Corolla more than 2 cm. long, not spurred (3-8 dm. high; flowers red-purple, summer) =Snapdragon, Antirrhinum majus.=
19a. Stem and foliage p.u.b.escent (1-3 dm. high; flowers blue, summer) =Small Snapdragon, Linaria minor.=
19b. Stem and foliage glabrous (2-6 dm. high; flowers blue, summer) =Toad-flax, Linaria canadensis.=
20a. Leaves with 1 or 2 lobes near the base (3-5 dm. high; flowers purple, summer) =Gerardia, Gerardia auriculata.=
20b. Leaves linear (2-6 dm. high; flowers rose-purple, summer and autumn) (Gerardia) --21.
20c. Leaves lanceolate or broader, not lobed --26.
21a. Pedicels equaling or but little longer than the calyx, and conspicuously shorter than the subtending leaf --22.
21b. Pedicels much longer than the calyx, and generally equaling or exceeding the subtending leaf --24.
22a. Plants of moist ground, bogs, and sh.o.r.es --23.
22b. Plants of dry uplands =Gerardia, Gerardia aspera.=
23a. Corolla about 25 mm. long =Gerardia, Gerardia purpurea.=
23b. Corolla less than 20 mm. long =Gerardia, Gerardia paupercula.=
24a. Stem rough on the angles --25.
24b. Stem glabrous =Gerardia, Gerardia tenuifolia.=
25a. Leaves 2-5 mm. wide =Gerardia, Gerardia tenuifolia var. macrophylla.=
25b. Leaves thread-like, 1 mm. wide or less =Gerardia, Gerardia skinneriana.=
26a. Corolla 16 mm. long, or shorter --27.
26b. Corolla 20 mm. long, or longer --32.
27a. Corolla dull-purple, brown, or greenish; one sterile stamen present (1-2.5 m. high; flowers in summer) (Figwort) --28.
27b. Corolla blue or white (1-4 dm. high) --29.
28a. Sterile stamen purple =Figwort, Scrophularia marilandica.=
28b. Sterile stamen yellow =Figwort, Scrophularia leporella.=
29a. Flowers nearly or quite sessile (summer) --30.