104 



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 yerna. 



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, Buclinera 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 laeyigatus. 



36b. Corolla-tube abruptly enlarged just beyond the calyx (flow- 

 ers white, early summer) 



Beard-tongue, Pentstemon laeyigatus 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 midvein 



Hedge Hyssop, Gratiola yirginiana. 



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 Boot, Veronica yirginica. 



40b. Leaves alternate or opposite (Speedwell) 41. 



