10 American Midland Naturalist Monograph No. 7 



1. Plants with stems bearing 1 or more leaves. 



7. Flowers borne in a dense head on a common receptacle surrounded or 

 subtended by an involucre of bracts; fruit an achene: stipules none 



125. COMPOSITAE 



7. Flowers not borne in a dense head on a common receptacle surrounded or 

 subtended by an involucre. 



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



Arisaema in 141. Araceae 



8. Flowers not borne on a spadix surrounded by a spathe. 

 9. Flowers in umbels; petals 5; stamens 5; ovary inferior. 



10. Fruit dry. composed of 2 carpels; styles 2 92. Umbelliferae 



10. Fruit a berry; styles 5, or 3, or 2 91. Araliaceae 



9. Flowers not in umbels, or if so, the flowers not as above in all re- 

 spects. 



11. Corolla papilionaceous; fruit a legume or loment; leaves alter- 



nate, usually stipulate 54. Leguminosae 



11. Corolla not papilionaceous. 



12. Stem bearing only a single leaf or a pair or whorl of leaves. 

 13. Pistil 1. 



14. Style or stigma 1. 



15. Sepals and petals each 4; fruit a pod; leaflets 3 or 



5, toothed Dentaria in 18. Cruciferae 



15. Sepals 6; petals small, gland-like; seeds berry-like 



9. Podophyllaceae 



14. Styles 4 or 5 ; fruit a drupe 64. Adoxaceae 



13. Pistils several to many, separate, simple; fruit achenes or 



follicles 3. Ranunculaceae 



12. Stems with usually 2 or more alternate leaves, or 2 or more 

 pairs of leaves. 

 16. Leaves, or some of them, opposite. 

 17. Leaves pinnate or pinnately lobed. 



18. Sepals 4, purple, petaloid ; petals none; stamens 

 numerous; plants climbing; achenes with per- 

 sistent styles Clematis in 3. Rani;nculaceae 



18. Sepals not as above; corolla present; stamens few; 

 plants not climbing. 

 19. Flowers blue or white; fruit a capsule. 



20. Corolla regular; stamens 5 



106. Hydro? hvllaceae 



20. Corolla 2-lipped; stamens 4 



108. ScROPHt'LARIACEAE 



19. Flowers yellow or pink. 



21. Flowers yellow; stamens 10; fruit 5-angled, 



spiny Tribulus in 40. Zygophyllaceae 



21. Flowers pink; stamens 3; fruit 1 -seeded .... 



123. Valerianaceae 



17. Leaves palmately lobed, or digitate, or trifoliolate; 

 petals none; fruit an achene. 



22. Flowers small, green, unisexual; leaves digitately 

 divided into 5-11 serrate, acuminate divisions 

 72. Cannabinaceae 



22. Flowers not green; sepals petal-like 



3. Ranunculaceae 



