

[Vol. 2 



116 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



face the fertile and sterile sporophylls, prevails in the earlier 

 orders of both classes, in the smaller, continuing through the 

 Alis mat ales, Liliales, Arales, Pahnales, and Graminales, and 

 aggregating more than 11,700 species. In the larger class the 

 strobiloid structure prevails throughout fourteen orders, from 

 the Ranales to the Lamiales, and aggregating more than 53,000 

 species. In these strobiloid flowers, as a result of the domi- 

 nance of the strobilar structure, we have what has been known 

 as the hypogynous form of flower. In both classes the strobi- 

 loid flowers show progressive modifications involving the 

 perianth (actinomorphy to zygomorphy, diplochlamydy to 

 achlamydy), the stamens (polystemony to oligostemony), the 

 carpels (polycarpy to oligocarpy), the ovules (multiovulate to 

 rariovulate). In the larger class the perianth modifications 

 proceed with such regularity that we may recognize lower 

 (apopetalous), and higher (sympetalous) groups of orders, 

 but this is not observed in the smaller class, where indeed 

 sympetaly is never more than sporadic, and does not become 



a fixed structure. 

 In summary fashion I may now outline the taxonomy of the 



flowering plants : 



The opposite-leaved class (Oppositifoliae, or dicotyledons) 

 is the first to emerge from the cycadean phylum, appearing 

 as the ranalean complex. 



From this Ranalean type arises the alternate-leaved class 

 of flowering plants (Alternifoliae, or monocotyledons) as apo- 

 carpous Alismatales, and these soon merge into the 

 syncarpous Liliales, which are successively more and more 

 modified in the Arales, Pahnales and Graminales. From 

 Liliales by a cotyloid modification the mostly actinomorphic 

 epigynous Iridales are derived, and from these again the 

 zygomorphic epigynous Orchidales. 



Eeturning to flie Ranales, we find that they give rise first 

 to five apopetalous, polycarpellate orders with gradually in- 

 creasing syncarpy, namely Malvales, Geraniales, Guttiferales, 

 Rhoeadales, and Caryophyllales. From the last arise three 

 orders of sympetalous, polycarpellate plants, the Ebenales, 

 Ericales and Primulales, and the latter have developed the 



