Scrophulariaceae, the Figwort Family
Herbs with opposite or alternate leaves and usually irregular flowers; corolla of united petals, bearing the 2 or 4 (or rarely 5) stamens attached; petals actually 5, but sometimes apparently only 2 or 4; a sterile fifth stamen sometimes present; ovary superior, 2-celled.
| 1a. Anther-bearing stamens 5 (6-15 dm. high; flowers in summer) (Mullein) — 2. | |
| 1b. Anther-bearing stamens 4; a sterile fifth stamen may or may not be present — 3. | |
| 1c. Anther-bearing stamens 2 — 37. | |
| 2a. Leaves densely white-woolly; flowers yellow, in dense spikes | Mullein, Verbascum thapsus. |
| 2b. Leaves smooth or nearly so; flowers yellow or white, in loose racemes | Moth Mullein, Verbascum blattaria. |
| 3a. Flowers (not the bracts) greenish-yellow, yellow, or orange — 4. | |
| 3b. Flowers blue, purple, brown, red, pink, or white, never yellow — 16. | |
| 4a. Flowers in dense terminal leafy-bracted spikes — 5. | |
| 4b. Flowers in loose racemes or axillary — 9. | |
| 5a. Corolla 7 mm. long or less, or none — 6. | |
| 5b. Corolla 12 mm. long or more — 7. | |
| 6a. Leaves alternate (3-6 dm. high; early summer) | Synthyris, Synthyris bullii. |
| 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) | Butter-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 pubescent — 15. | |
| 14a. Principal stem-leaves pinnatifid | False Foxglove, Gerardia virginica. |
| 14b. Principal 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 pubescent (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 shores — 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. | |
| 29b. Flowers on pedicels 10 mm. long or more (spring) — 31. | |
| 30a. Foliage-leaves prominently toothed — 6b. | |
| 30b. Foliage-leaves entire, or with 1 or 2 small teeth at the base | Cow Wheat, Melampyrum lineare. |
| 31a. Corolla more than 10 mm. long, blue and white | Blue-eyed Mary, Collinsia verna. |
| 31b. Corolla 5-8 mm. long, blue and white | Collinsia, Collinsia parviflora. |
| 32a. Flowers solitary in the axils of the upper foliage-leaves (4-8 dm. high; flowers blue, in summer) (Monkey Flower) — 33. | |
| 32b. Flowers in dense terminal or subterminal spikes (3-9 dm. high; summer) — 34. | |
| 32c. Flowers in loose terminal panicles (flowers white or pale-violet) (Beard-tongue) — 35. | |
| 33a. Leaves clasping at the base | Monkey Flower, Mimulus ringens. |
| 33b. Leaves petioled, not clasping | Monkey Flower, Mimulus alatus. |
| 34a. Stem and foliage glabrous (flowers white) | Turtlehead, Chelone glabra. |
| 34b. Stem and foliage pubescent (flowers purple) | Blue Hearts, Buchnera americana. |
| 35a. Stem finely pubescent (3-6 dm. high; flowers pale-violet, late spring) | Beard-tongue, Pentstemon hirsutus. |
| 35b. Stem glabrous below the inflorescence (6-12 dm. high) — 36. | |
| 36a. Corolla-tube gradually enlarged from base to tip (flowers pale-violet, in early summer) | Beard-tongue, Pentstemon laevigatus. |
| 36b. Corolla-tube abruptly enlarged just beyond the calyx (flowers white, early summer) | Beard-tongue, Pentstemon laevigatus var. digitalis. |
| 37a. Corolla distinctly irregular, 2-lipped (1-4 dm. high; flowers yellowish or white, summer) — 38. | |
| 37b. Corolla regular or nearly so and 2-lobed, or none — 6a. | |
| 37c. Corolla regular or nearly so, 4-lobed — 40. | |
| 38a. Leaves narrowed at the base, with mid-vein | Hedge Hyssop, Gratiola virginiana. |
| 38b. Leaves rounded or somewhat clasping at the base, with 3-5 principal veins (False Pimpernel) — 39. | |
| 39a. Peduncles longer than the subtending leaves | False Pimpernel, Ilysanthes anagallidea. |
| 39b. Peduncles shorter than the subtending leaves | False Pimpernel, Ilysanthes dubia. |
| 40a. Leaves whorled (8-20 dm. high; flowers white or pale-blue, in spikes, summer) | Culver’s Root, Veronica virginica. |
| 40b. Leaves alternate or opposite (Speedwell) — 41. | |
| 41a. Flowers in racemes, which arise from the axils of the opposite leaves (flowers pale-blue to nearly white, late spring and summer) — 42. | |
| 41b. Flowers solitary in the axils of leaf-like bracts, or in terminal bracted racemes (1-4 dm. high; spring and summer) — 46. | |
| 42a. Stem and foliage glabrous; swamp plants 2-7 dm. high — 43. | |
| 42b. Stem and foliage pubescent; plants of dry ground, 1-3 dm. high — 45. | |
| 43a. Leaves linear or narrowly lanceolate | Marsh Speedwell, Veronica scutellata. |
| 43b. Leaves ovate or ovate-lanceolate — 44. | |
| 44a. Stem-leaves sessile and somewhat clasping | Water Speedwell, Veronica anagallis-aquatica. |
| 44b. Stem-leaves on short petioles | Brooklime, Veronica americana. |
| 45a. Leaves narrowed at base into a petiole | Speedwell, Veronica officinalis. |
| 45b. Leaves rounded or heart-shape at the base | Speedwell, Veronica chamaedrys. |
| 46a. Bracteal leaves entire; stem glabrous or minutely pubescent — 47. | |
| 46b. All leaves serrate; foliage pubescent (flowers blue) — 48. | |
| 47a. Flowers white, about 2 mm. wide | Speedwell, Veronica peregrina. |
| 47b. Flowers pale-blue with darker stripes, 3-4 mm. wide | Speedwell, Veronica serpyllifolia. |
| 48a. Flowers nearly sessile, about 2 mm. wide | Speedwell, Veronica arvensis. |
| 48b. Flowers on slender pedicels, 5-8 mm. wide | Speedwell, Veronica tournefortii. |