Xll KEY TO THE OKDEKS. 



Leaf -blades compound : fruit a samara. 



Oleaceae in Order OLEALES. 

 Ovules many : flowers aggregated into dense heads. 



Altingiaceae in Order ROSALES. 



Fruit many-seeded : seeds each with a tuft of hairs. Order SALICALES. 

 Calyx present at least in the staminate or in the perfect flowers. 

 Flowers, at least the staminate, in aments, or ament-like spikes. 

 Leaf-blades simple : ovule pendulous and anatropous. 



Pistillate flowers separate at maturity : fruit a nut or an achene. 



Order FAGALES. 

 Pistillate flowers forming aggregate fruits : fruit drupe-like. 



Artocarpaceae in Order URTICALES. 

 Leaf -blades pinnately compound : ovule erect and orthotropous. 



Order JUGLANDALES. 



Flowers, at least the staminate, not in aments. 

 a. Ovary superior. 



Gynoecium of 1 or several and distinct carpels : stigma and style 



solitary. 

 Carpel solitary. 



Ovary neither enclosed nor seated in a hypanthium or a calyx- 

 tube. 

 Flowers not solitary in axils : land plants. 



Urticaceae in Order URTICALES. 

 Flowers solitary in axils ; aquatic plants. 



Ceratophyllaceae in Order RANALES. 

 Ovary enclosed in or seated in a hypanthium or a calyx-tube. 



Order THYMELEALES. 

 Carpels several : 



Stamens inserted below the ovary. Families in Order RANALES. 

 Stamens inserted on the edge of a cup-shaped hypanthium. 



Rosaceae in Order ROSALES. 

 Gynoecium of 2 or several united carpels : stigmas or styles 2 or 



several. 

 * Ovary, by abortion, 1-celled and 1-ovuled. 



Leaves with sheathing stipules (ocreae). Order POLYGONALES- 

 Leaves estipulate, or if stipules are present they are not 



sheathing. 

 Trees or shrubs. 



Anthers opening by slits : ovary not seated in a hy- 

 panthium. Ulmaceae in Order URTICALES.. 

 Anthers opening by hinged valves : ovary seated in an- 

 accrescent hypanthium. 



Lauraceae in Order THYMELEALES. 

 Herbs or vines. 



t Leaves with stipules. 



Stipules herbaceous : inflorescence spicate or racem- 

 ose : leaf-blades palmately veined. 



Cannabinaceae in Order URTICALES. 

 Stipules scarious or hyaline : inflorescence cymose : 

 leaf-blades pinnately veined. 



Families in Order CHENOPODIALES. 

 ft Leaves without stipules. 



Stigmas entire. Order CHENOPODIALES.. 



Stigmas 2-cleft. 



Euphorbiaceae in Order EUPHORBIALES. 



** Ovary several-celled, or with several placentae, several-ovuled. 

 Stamens hypogynous, inserted under the gynoecium in the per- 

 fect flowers, not on a disk in the pistillate flowers. 

 Herbs. 



Flowers perfect. 



Ovary several-celled. 



Fruit baccate or nut-like, or a circumscissile cap- 

 sule, the carpels terminal on the receptacle. 



Families in Order CHENOPODIALES.. 

 Fruit of several carpels, lateral on the receptacle,, 

 each carpel circumscissile. 



Penthoraceae in Order ROSALES. 

 Ovary 1-2-celled. 



Stamens not tetradynamous, 4-8 : ovary 1-celled. 

 Order CHENOPODIALES.. 

 Stamens tetradynamous : ovary 2-celled. 



Brassicaceae in Order PAPAVERALES. 

 Flowers monoecious or dioecious. 



Euphorbiaceae in Order EUPHORBIALES. 

 Trees or shrubs. 



Ovary 4-celled : fleshy maritime shrubs. 



Batidaceae in Order CHENOPODIALES. 

 Ovary 2-celled : plants not fleshy. 



Oleaceae in Order OLEALES. 



