140 LESSONS IN BOTANY 



17. Leaves opposite 18, 



17. Leaves alternate 19. 



18. Fruit a pyxis, opening by a lid. 

 18. Fruit a capsule, opening by 4 or 5 valves. 

 19. Fruit a capsule, 5-cellcd, 5-liorned. 

 19. Fruit a fleshy, 4-oo-seeded berry. 

 19. Fruit dry, 1-seeded, opening by a lid. 

 20. Flowers on a spadix with a spathe. 

 20. Flowers in a long, naked spike. Stamens 6 or 7. 

 20. Flowers solitary, axillary, minute. Water-plants.. ..21. 

 21. Stamen 1. Leaves opposite. 

 21. Stamens 2. Leaves alternate, dissected. 

 21. Stamens 12-2-4. Leaves whorled, dissected. 



22. Flowers, none of them in aments 23. 



22. Flowers (imperfect), the sterile only in aments.... 34. 



22. Flowers (imperfect), both the sterile and the fertile in aments. . .35. 



23. Leaves opposite 24. 



23. Leaves alternate 27. 



24. Stamens 2. * Order 99 



24. Stamens 3. Parasites. Mistletoe — Lor anths. 108 



24. Stamens 4-9 25. 



25. Fruit a double, 2-winged samara. * Order 40 



25. Fruit not winged 26. 



26. Seeds 6. Low shrubs. Box. Spurgeworts. 112 



26. Seed 1. Shrubs. Oleasters. Ill 



27. Style or stigma 1. Seed 1 28. 



27. Styles or stigmas 2 31. 



27. Styles or stigmas 3-9 32. 



28. Calyx free from the ovary. . . .29. 



28. Calyx adherent to the ovary 30 



29. Anthers opening by valves. * Laurels. 107 



29. Anthers opening by slits. Daphnads. 11(? 



SO. Seeds 2-4. Shrubs. ^andalworts. 109 



80. Seed 1. Trees. * Order 65 



31. Stamens numerous. * Order 62 



31. Stamens as many as the calyx lobes. Uhmvorts. 113 



32. Leaves pinnate. Pistils 5. {Prickcy Ash.) Order 37 



82. Leaves simple, linear, evergreen. Crowberries. 116 



32. Leaves simple, not linear 33. 



33. Flowers 3- parted. Fruit dry. {StiUingia.) Spurgeworts. 112 



83. Flowers 4 or 5-parted, Fruit fleshy. {Buckthorns.) Order 43 

 34. Nut or nuts in a cup or involucre. Leaves simple. * Mastworts. 119 

 84. Nut naked, a tryma (§ 172). Leaves pinnate. Eichory worts. 118 



