140 



LESSONS IN BOTANY 



17. Leaves opposite .... IS. 



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-celled, 5-horned. 

 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. 12-24. Leaves whorled, dissected. • 



22. Flowers, none of them in amenta" . . .28. 



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



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



23. Leaves opposite 24. 



23. Leaves alternate 27. 



24. Stamens 2, 



24. Stamens 3. Parasites. MistUtoe- 



24. Stamens 4^9 25. 



25. Fruit a double, 2-winged samara. 



25. Fruit not winged 26. 



26. Seeds 6. Low shrubs. Box. 

 26. Seed 1. Shrubs. 

 27. Style or stigma 1. Seed i:... 28. ' 



27. Styles or stigmas 2 81. 



27. Styles or stigmas 8-9 32. 



28. Calyx free from the ovarj'. . . .29. 



Calyx adherent to the ovary 30 



29. Anthers opening by valves. 

 29. Anthers opening by slits. 

 30. Seeds 2-4. Shrubs. 

 80. Seed 1. Trees. 

 Stamens numerous. 

 Stamens as many as the calyx lobe's. 

 82. Leaves pinnate. Pistils 5. 

 - 32. Leaver simple, linear, evergreen. 



82. Leaves simple, not linear 83. 



83. Flowers 3-parted. Fruit dry. , {ShUingia.) Spurgeworts. 112 

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



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



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



28. 



31. 

 81. 



* Ordir 22 

 » Order 21 



* Order 60 

 " I'okeweeda. 103 

 Amaranths. 106 



* Order 131 

 Lvaard-tmU. 123 



Starworts. 124 



Threadfoots. 125 



• Bornwoi'ta. 126 



..35. 



* Order 99 

 -Zoi'anths. 106 



* Order 40 



Spurgeworts. 112 

 Oleasters. Ill 



* Laurels. 107 



Daphnads. 110 



Sandaheorts. 109 



* Order 65 



. * Order 62 



Blmaiiorts. 113 



(Friokty Ash.) Order 37 



Orowberi'ies. 116 



