414 The Ohio Naturalist. [Vol. XII, No. 2, 



THALAMIFLORAE. 



Herbs or woody plants with hypogynous, choripetalous or 

 apetalous flowers, calyx commonly of distinct sepals and inserted, 

 with the other parts of the flower, directly on the floral axis. 



Synopsis. 

 I. Carpels many to one, spiral or cyclic, usually free or only 

 shghtly united; stamens usually numerous. Ranales. 

 II. Carpels more or less united, cyclic. 



1. Herbs with insectivorous leaves; carpels .5-3. Sarraceniales. 



2. Herbs or woody plants with normal leaves, not 



insectivorous. 



a. Carpels 2 or more with parietal placentae; perianth 



usually with an even number of segments, the 

 flowers commonly isobilateral. Brassicales. 



b. Carpels mostly 5 or 3; stamens mostly 10 or 5, or a 



reduction from 10; ovules pendulous. Geraniales. 



c. Carpels many to 3, ovules few; stamens indefinite, 



monadelphous, branched or clustered, or by reduc- 

 tion separate and few; sepals valvate. Malvales. 



d. Carpels 2 or more, commonly with parietal placentae; 



stamens usually indefinite ; sepals and petals usually 

 5, sepals imbricated or convolute. Guttiferales. 



CENTROSPERMAE. 



Mostly herbaceous plants Avith hypogynous syncarpous 

 flowers; usually apetalous except in the lowest families; ovulary 

 usually with a central basal ovule or with many ovules on a 

 central placenta. 



Synopsis. 

 I. Perianth present consisting of a calyx and corolla or of a 

 calyx only. 



1. Embryo curved, coiled, or annular, fruit not an achene. 



a. Emit a capsule, berry, or anthocar]r, calyx present; 



corolla present or absent. Caryophyllales. 



b. Fruit a utricle; calyx present, corolla none. 



Chenopodiales. 



2. Embryo straight or nearly so; fruit an achene. Polygonales. 

 II. Perianth none or vestigial; ovules usually orthotropous. 



Piperales. 



CALYCIFLORAE. 



Perianth and stamens usually borne on a perigynous disk or 

 hypanthium which is sometimes united with the ovulary; carpels 

 free or united; calyx usually of united sepals, petals when present 

 separate. 



