GAMOPETALJE. KEY TO THE ORDERS. 65 



(13) Flowers regular. (14). 

 Flowers irregular. (37). 



(14) Stamens hypogynous. (15). 

 Stamens epipetalous. (18). 



(15) Ovary 1-celled, ovule 1, pendulous. Herbs Plumbagineae, 



Ovary 5-celled, cells many-ovuled. (16). 



(16) Trees, shrubs or shrubby herbs, leafy. (17). 



Leafless herb, parasite Monotropeae. 



(17) Anthers opened by terminal pores Ericaceae. 



Anthers opened by longitudinal slits Diapensiaceae. 



(18) Ovary of two free carpels with connate styles or stigmas, or carpels 



separable. Carpels not confluent. (19). 

 Ovary of two or more confluent carpels. (21). 



(19) Leaves opposite. (20). 



Leaves alternate, carpels each 2-lobed Apocynaceae, (Cerbera}. 



(20) Pollen grains free, Apocynaceae. 



(in Melodinm carpels confluent, in Rwnvdfia they are partly confluent). 

 Pollen in waxy or granular masses Asclepiadeae. 



(21) Ovary 1-celled, placenta free central, stamens opposite collora-lobes (22). 

 Ovary 1 or more celled, placenta not free central. (23). 



(22) Herbs, fruits capsular Primulaceae. 



Trees or shrubs, fruits baccate or somewhat Iraccate, not dehiscing. . . . 



Myrsineae. 



(23) Leaves opposite, rarely ternate. (24). 

 Leaves alternate or all radical. (29). 



(24) Trees or slirubs. (25). 

 Herbs. (28). 



(25) Stamens 2, ovary 2-celled, cells 1-oruled Oleaceae. 



Stamens 4-5. (26). 



(26) Anthers coiinivent, adnate to stigmas Apocynaceae. 



Anthers free. (27). 



(27) Ovary 1-4-cellcd, placenta axile or sub-bnsal. (28). 



Ovary 1-celled, placenta parietal, ovules very many. . . Gentian aceae. 



