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.