XX 
KEY TO THE ORDERS. 
Plants with relatively firm stems and leaves, not succulent. 
Order 25. Ranales. 
Plants with succulent stems and leaves. 
Crassulacese in Order 27. Rosales. 
Stamens on the margin of a hypanthium (the hypanthium very small 
in some Saxifragaceae). Order 27. Rosales. 
2. Carpels several and united, 
a. Ovary superior. 
$ Stamens inserted at the base of the ovary or receptacle. 
§ Stamens numerous. 
Sepals imbricated. 
Calyx deciduous. Order 26. Papaverales. 
Calyx persistent. 
Styles or stigmas distinct or united, but not discoid ; land 
plants. Capparidacese in Order 26. Papaverales. 
Styles or stigmas united into a disk ; aquatic plants ; petals 
and sepals numerous. 
Nymphaeaceae in Order 25. Ranales. 
Sepals valvate; stamens with united filaments. 
Order 33. Malvales. 
§§ Stamens few, not over twice as many as the petals. 
Stamens as many as the petals and opposite them. 
Anther-sacs opening by hinged valves. 
Berberidaceae in Order 25. Ranales. 
Anther-sacs opening by slits. 
Flowers monoecious. Order 30. Euphorbiales. 
Flowers perfect. 
Portulacaceae in Order 24. Chenopodiales. 
Stamens as many as the petals and alternate with them, or 
more, sometimes twice as many. 
Stamens 6 : petals 4: sepals 2 or 4. 
Families in Order 26. Papaverales. 
Stamens, petals and sepals of the same number, or stamens 
more, usually twice as many as the sepals or petals. 
Ovary 1-celled. 
Ovules, or seeds, on basal or central placentae. 
Families in Order 24. Chenopodiales. 
Ovules, or seeds, on parietal placentae. 
Stamens with united filaments and no staminodia. 
Order 33. Malvales. 
Stamens with distinct filaments. 
Staminodia present. 
Parnassiaceae in Order 27. Rosales. 
Staminodia wanting. 
Families in Order 34. Hypericales. 
Ovary several-celled. 
Stamens adnate to the gynoecium. 
t Asclepiadaceae in Order 43. Asclepiadales. 
Stamens not adnate to the gynoecium. 
Stamens with wholly or partly united filaments. 
Anthers opening lengthwise. 
Families in Order 28. Geraniales. 
Anthers opening by pores. 
Order 29. Polygalales. 
Stamens with distinct filaments. 
Anthers opening by pores. 
Families in Order 39. Ericales. 
Anthers opening by slits. 
Stigmas or styles distinct and cleft, or foliaceous, 
or united by pairs. Order 30. Euphorbiales. 
Stigmas or styles all distinct or all united, neither 
cleft nor foliaceous. 
134 
169 
169 
148 
168 
147 
229 
148 
221 
125 
148 
113 
229 
175 
231 
270 
217 
221 
258 
221 
