18 American Midland Naturalist Monograph No. 2 



13. Flowers all or mostly in spikes or terminal cymes or pani- 

 cles, or else all in dense, sessile, axillary clusters; styles 

 2 or 3, or I and branched. 

 14. Flowers subtended by scarious bracts, the sepals sharp- 

 pointed; leaves not linear or with spiny tips; plants 



never white-mealy 52. AmaranthacEAE 



14. Flowers not subtended by scarious bracts; sepals not 

 awn-pointed; leaves linear and with spiny tips, or the 

 plants whitish-mealy at least about the inflorescence 



or the lower surface of the leaves 



51. Chenopodiaceae 



10. Flowers not green; petals present, or the calyx colored and petal-like. 

 15. Leaves cordate, velvety-pubescent; petals yellow; carpels 12- 



15, pubescent, dehiscent at the apex 



Abutilon in 105. Malvaceae 



15. Leaves not cordate, or if so, not velvety-pubescent. 



16. Sepals 2 57. PORTULACACEAE 



16. Sepals more than 2 (rarely cohering in pairs). 



17. Flowers borne en the lower part of the stem near the 

 ground; calyx S-shaped; petals none; leaves petioled, 



cordate or halberd-shaped 



Arisiolochia in 49. Aristolochiaceae 



17. Flowers borne on the upper part of the stem; calyx never 

 curved. 

 18. Ovary inferior. 



19. Petals yellow or purplish; fruit a several-seeded 



capsule 115. Onagraceae 



19. Petals none, the sepals whitish and petal-like; fruit 

 I -seeded, indehiscent; plants glabrous, glaucous 



47. Santalaceae 



18. Ovary superior. 



20. Petals none, the 5 sepals petal-like; flowers in 



racemes; fruit a juicy dark purple berry 



53. Phytolaccaceae 



20. Petals 4-6; fruit a capsule or pod. 



21. Flowers regular; anthers opening longitud- 

 inally. 

 22. Style 1, or stigma sessile. 



23. Petals and stamens hypogynous. 



24. Sepals, petals, and stamens each 

 5; fruit a 5-loculed capsule .. 



87. LiNACEAE 



24. Sepals and petals each 4; stamens 

 6, four long and two short; 

 fruit a I- or 2-loculed capsule 



71. Cruciferae 



23. Petals and stamens inserted on the 

 calyx; branches usually more or 



less angled 113. Lythraceae 



22. Styles 2; petals 5; sepals 5, reflexed; 



stamens 10; leaves chiefly basal 



77. Saxifragaceae 



21. Flowers irregular; anthers opening by termi- 

 nal pores 93. Polygai.aceaE 



7. Petals united (the corolla sympetalous). 

 25. Corolla regular (actinomorphic). 



26. Flowers 4-5 cm. long, white; calyx enclosed or subtended by a pair of 

 broad bracts; leaves often more or less cordate at base; fruit a 

 capsule; plants with milky juice 130. CoNVOLVULACEAE 



