SYNOPSIS OF THE ORDERS OF PLANTS CONTAINED IN VOLUME YII 



OF THE SILYA OF NORTH AMERICA. 



Class L DICOTYLEDONOUS or EXOGENOUS PLANTS. 



Stems increasing in diameter by the annual addition of a layer of wood inside the bark. Leaves netted-veined. Embryo 

 with a pair of opposite cotyledons. 



SuB-CiiAss L AngiospermSB. Pistil, a closed ovary containing the ovules and developing into the fruit. 



Division III, ApetalSB. Corolla 0. Stamens inserted on the petaloid calyx, or hypogynous. 



44. Lauracese. Flowers perfect or dioecious. Stamens 9 to 12, hypogynous. Ovary superior, 1-celled. 

 Ovule solitary, suspended, anatropous. Seed exalbuminous- Leaves alternate or opposite, exstipulate. 



45. Euphorbiaceae. Flowers unisexual. Stamens 1, few or many. Ovary superior, usually 1-celled. Ovule 

 solitary, or 2, collateral, descending, anatropous. Seed albuminous- Leaves usually alternate or opposite, stipulate. 



46. Ulmacese, Flowers perfect or polygamo-monoecious. Stamens as many as the lobes of the calyx, 

 hypogynous. Ovary superior, 1-celled. Ovule solitary, suspended, anatropous. Fruit a compressed winged 



samara, or drupaceous. Seed albuminous. Leaves alternate, stipulate. 



47. Moracese. Flowers unisexual. 



caljrx. Ovary superior, 1-celled. 



Ovule 



Seed albuminous. Leaves alternate or opposite, stipulate. 



48. Platanacese. Flowers monoecious In dense unisexual capitate heads. Stamens as many as the lobes of 

 the calyx. Ovary superior, 1-celled. Ovule usually solitary, suspended, orthotropous. Seed albuminous. Leaves 



alternate, stipulate. 



49. Leitneriaceae. Flowers amentaceous, dioecious. Stamens 3 to 12. Ovary superior, l-celled. Ovule 



solitary 



Fruit drupaceous. Seed albuminous. Leaves alternate, exstipulate. 



50. Juglandaceae. Flowers monoecious. Stamens indefinite. Ovary inferior, 1-celled. Ovule erect, ortho- 

 tropous. Fruit a nut inclosed in an indehiscent or 4-valved woody or fleshy involucre. Leaves alternate, exstipulate. 



