RANALES 403 



carpel margins, the consequent decurrent stigmatic crest — probably the 

 earliest stigma — and the broad laminar stamen are the outstanding 

 primitive features of the ranalian flower. The nondehiscent fruit with 

 many seeds that are freed only by decay of the fruit walls is perhaps a 

 first step in the development of the achene type of fruit. 



In restriction of the area of ovule-bearing from the "allover" pattern 

 of typical laminar distribution to broad lateral bands, Degeneria pre- 

 sents a stage in the evolutionary development of submarginal placenta- 

 tion. The vascular structure of the carpel demonstrates this. The ovule 

 traces are derived from both the dorsal and the median veins. Though 

 the ovules are restricted to two rows, their traces do not arise directly 

 below the ovules, as in submarginal placentation. ( This stage is seen also 

 in Drimijs.) 



The wood, though advanced over the vesselless type, is primitive, 

 with multiperforate, scalariform vessels and scalariform pitting. The 

 nodes are multilacunar, with five traces from five gaps. 



All characters considered, the Degeneriaceae are one of the most 

 primitive angiosperm families, similar in degree of primitiveness to the 

 Magnoliaceae, Eupomatiaceae, and Winteraceae. Thev seem to belong 

 to the magnolian alliance, forming another isolated family, with spe- 

 cialized perianth and gynoecium. 



Myristicaceae 



The Myristicaceae, a small tropical family, have small, apetalous, uni- 

 sexual flowers, extrorse anthers, connate stamens, and a solitary carpel. 

 At least ten families of the Ranales and Laurales have been considered 

 their probable relatives. The family is usually placed in the Ranales, 

 with closer affinities still uncertain. In taxonomic treatments, this family 

 has perhaps most often been placed close to the Lauraceae, which it 

 resembles in flower structure. Wood structure supports this treatment. 

 But its monocolpate pollen, its embryology, and its ruminate endosperm 

 have suggested affinity with the Annonaceae. Its members have been 

 called "apetalous annonads." In some opinions, the Annonaceae, Eu- 

 pomatiaceae, Magnoliaceae, and Myristicaceae form a complex of re- 

 lated ranalian families, with Myristicaceae approaching the Lauraceae 

 in some characters. But the wood of the Annonaceae and Eupomatiaceae 

 differs greatly from that of the Myristicaceae. 



In this family, the association of monocolpate pollen with unisexuality, 

 a solitary carpel, connate stamens, and wood with both scalariform 

 and simply perforate vessels is surprising. All genera have tanniniferous 

 ducts in the wood rays, a character unknown elsewhere. (Similar tubes 

 are present in the pith of Eupomatia.) Wood anatomy lends no support 

 to the frequently made suggestion of relationship to the Annonaceae. 

 The family appears to be close to the Lauraceae. A study of evolu- 



