Key to the Orders. 11 



PAGE 



14. Leaves pinnate; fruit [walnut or hickor>--nut naked Juglandacea. 27 



11. Leaves simple: fertile flowers and fruit in an involucre or cup. ./^aj-ac^t?. 32 



1-3. Ovary 1-celled, many-seeded: seeds with a down Salicacete. 29 



1.'). Ovary l-'J-celled, each cell 1-ovuled : fruit 1-seeded (16. 



If). Parasitic on trees: fruit a berry Loranlhacece. 36 



111. Trees or shrubs, not parasitic 17 



17. Calyx of the fertile flowers succulent in fruit Moracecr. 36 



17. Calyx none or rudimentarj- or scale-like ,18) 



18. Style and stigma, one, simple : the flowers in heads Plalanacecc. 60 



18. Styles or long stigmas two [19 . 

 19. Fertile flowers 2 or 3 under each scale of the catkin or each in a 



sac or with bractlets Betulaccer. .'A 



19. Fertile flowers single under each scale : nutlets naked, waxy-coated 



or drupe-like Myricacetr. 29 



20. Ovary or its cells containing many ovules 21 . 



20. Ovary or its cells containing 1-2 rarely 3-4 ovules 22. 



21. Ovary one and inferior: or 2 or more separate ovaries Z'l,. 

 21. Ovar\- one, superior: or the calyx entirely wanting :38 . 

 22. Pistils more than one, distinct or nearly so ,23,. 

 22. Pistil one, either simple or compound 2•^). 



23. Stamens on the calyx ; leaves with stipules Rosacea. 60 



23. Stamens inserted on the receptacle 21 . 



24. Leaves punctate with translucent dots Riitaceer. 97 



24. Leaves not dotted : calyx often petaloid Ranuncnlacecs. 42 



2."). 0\-arj- half inferior. 2-celled : styles 2, pod 2-beaked, -woody . Haiiiaineltdacece. .59 

 "2.'). Ovarv" wholly inferior in perfect or pistillate flowers 26 . 



2.J. Ovarj' reallj- free but invested by the cal>-x tube Rosacea. (K) 



25. Ovary plainly free from the calyx, or calyx wanting 29 . 



26. Aquatic herbs ; ovary 4-cened Callitricliacece. 74 



26. Woody plants or herbs : ovary 1-2-celled 27 . 



27. Stigmas running down one side of style Cornacecr. 89 



27. Stigmas terminal, with or without a stj'le 2.H . 



"28. Parasitic on branches of trees: anthers sessile Loranlhacece. 36 



28. Not parasitic above ground: anthers on filaments Sanlalacea. 37 



2'.i. Stipules sheathing the stem at the nodes :!0 . 

 2VI. Stipules none, dr not sheathing the stems 31 . 



30. Tree: calyx none: flowers monoecious in heads Platanaccce. 60 



:jO. Herbs : calyx present, usually petaloid PolygonacccE. 37" 



31. Aquatic herbs : leaves opposite, entire Callitrichaccir. 74 



31. Herbs, not aquatic 32 . 

 31. Shrubs or trees 33 . 

 32. Ovary 3-celled ; juice usually railk\-, fls. in an in\-o\ucrt. £up/iordiacea. 74 

 :-i2. Ovary 1-celled: juice not milky, stipules scarious. ... Caryop/iy//acea. 34 

 33. Ovules a pair or several in each cell of the ovarj- \M . 

 :>;. Ovules single in each cell of the ovary '3.') . 



34. Fruit a 2-celled, double .samara Aceiacece. 77 



;>1. Fruit a 1-celled, 1-seeded samara or drupe Oleacecr. 96 



Z\. Fruit a 2-beaked, woody capsule Hamamelidaceee. .59 



35. Ovary 3-celled : branches often thorny Rhamnacecr. 79 



35. Ovary 1 to 2-celled: styles or stigmas 2-cleft (36;. 



