14 American Midland Naturalist Monograph No. 7 



22. Sepals 2 Claytonia in 25. Portulacaceae 



22. Sepals 5. 



23. Styles 2; anthers opening longitudinally; 

 leaves not evergreen; fruit 1-loculed 



62. Saxifragaceae 



23. Style 1 ; anthers opening by terminal 

 pores; leaves evergreen; fruit a 5- 



loculed capsule 93. Ericaceae 



10. Scapes or peduncles 1 -flowered. 



24. Leaves toothed or lobed ; petals separate, or absent. 



25. Leaves large, peltate, palmately 7-9-lobed; petals 6-8, white; 

 sepals 6, petaloid, fugacious; fruit a yellowish green berry 



9. Podophyllaceae 



25. Leaves not peltate. 



26. Fruit an achene; flowers yellow, bluish or white; petals 

 sometimes absent, the sepals then petal-like; juice 



watery 3. Ranunculaceae 



26. Fruit a capsule ; petals present. 



27. Plants with red juice; leaves thickish; petals 4-15 (usu- 

 ally 8), white; flower regular; capsule acute 



Sanguinaria in 13. Papaveraceae 



27. Plants with colorless juice; leaves thin; petals 5; flowers 



irregular, blue, yellow, or white; capsule obtuse 



1 1. Violaceae 



24. Leaves entire. 



28. Leaves reniform. cordate, or ovate; fruit a capsule. 



29. Leaves pubescent beneath, reniform; flowers brownish 

 purple; calyx 3-lobed ; petals none; stamens 12; ovary 



inferior; woodland plants 



Asarum in 87. Aristolochiaceae 



29. Leaves glabrous; flowers blue or white. 



30. Petals, sepals, stamens each 5; staminodia present; stig- 

 mas 4; plants of bogs and springy places 



63. Parnassiaceae 



30. Perianth 6-parted ; staminodia none; stamens 3; stig- 

 mas 3; plants of muddy shores 



Heteranthera in 134. Pontederiaceae 



28. Leaves not as above. 



31. Flowers on a spadix surrounded by a spathe; fruit a berry 



141. Araceae 



31. Flowers not on a spadix; spathe none; fruit not a berry. 

 32. Leaves orbicular, peltate; flowers 10-25 cm in diameter, 



pale yellow; petals and stamens numerous 



6. Nelumbonaceae 



32. Leaves not peltate; flowers smaller. 



33. Flowers irregular; ovary inferior; stamens 1 or 2 .... 



140. Orchidaceae 



33. Flowers regular. 



34. Pistils numerous, simple, borne on a slender 

 spike-like receptacle; stamens 5-20; sepals 5, 

 minutely spurred at base; petals 5; leaves all 



basal, linear-spatulate 



Myosurus in 3. Ranunculaceae 



34. Pistil 1, compound. 



