170 MORPHOLOGY OF THE ANGIOSPERMS 



years later. The views now generally accepted are that the conifers 

 are not on the direct ancestral line of the angiosperms; that the ane- 

 mophily of the Amentiferae is derived, accompanying high specializa- 

 tion in inflorescence and flower structure; that the primitive flower was 

 bisexual, not unisexual. 



Without question, anemophily is advanced in some taxa: in Fraxinus, 

 a member of a highly specialized entomophilous family with petaloid 

 flowers; in the Platanaceae, a family of the petaloid Rosales, with 

 greatly reduced flowers and inflorescences; in the grasses and sedges, 

 likewise with greatly specialized and reduced flowers and inflorescences. 

 The recognition of the woody Ranales as the most primitive living 

 angiosperms further emphasizes entomophily as primitive. Pollination 

 in Eupomatia — in flower structure, one of the most primitive angio- 

 sperms — is by beetles, the ancient and primitive group of insects. The 

 flower structure of this genus is such that pollination by wind is impos- 

 sible; pollen can reach the carpels only by beetles eating through an 

 enclosing sheath of staminodia (Fig. 142). Pollination is also only, or 

 largely, by beetles in Cahjcanthiis, Magnolia, lUicium, Paeonia, and in 

 the herbaceous Nymphaeaceae, especially Victoria, now generally recog- 

 nized as primitive taxa. Little is known of methods of pollination in 

 other genera of the Magnoliaceae and in the primitive families, Winter- 

 aceae, Degeneriaceae, Himantandraceae, Trochodendraceae, and Tetra- 

 centraceae. 



There are strong similarities in features of floral structure related to 

 pollination in Eiipomatia and Cahjcanthiis. In both genera, the stigmas 

 are enclosed in a chamber readily accessible only to chewing insects; 

 food, also available only to chewing insects, is abundant. This food con- 

 sists of "food bodies," richly protoplasmic, succulent tissue. These food 

 bodies are pads on the surface of the inner staminodia in Eupomatia 

 laurina (Fig. 69F); apical clusters of cells on inner petals, stamens, and 

 staminodia in Cahjcanthus (Fig. 69A to D) (a small amount of nectar 

 has been reported in one species) and E. hennettii; in lUicinm, they 

 are "succulent knobs in the center of the flower." There are no nec- 

 taries as such in these taxa. In Eupomatia laurina, the beetles, trapped 

 inside the floral chamber, rarely escape until the outer floral organs 

 are shed; evidence of their long feeding and imprisonment is the 

 presence of debris and excrement. Pollination by beetles is crude but 

 effective. In higher families, it is replaced by true nectaries, surface 

 areas or organs that supply fluid food over a considerable period. 



Beetles are also associated in varying percentages with other pol- 

 linizing insects, especially in families with small flowers in dense in- 

 florescences, such as the Cornaceae, Caprifoliaceae, Fagaceae {Cas- 

 tanea), Saxifragaceae ( Hydrangeae ) . 



