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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 9, No. 3 



I 



Duidaea. 



The distinctive genus Duidaea has pollen grains, in D. pinifolia, similar to 

 those of Gongylolepis. Grains of D. pinifolia (fig. 100 A-C) are sphaeroidal and 

 spinose, and have thick walls. Rods of the inner ektexine (fig. 100 C) are rel- 

 atively small. No features other than those found in Gongylolepis, however, 

 characterize D. pinifolia. The exine structure of D. tatei (fig. 101 A-C), therefore, 

 is surprising. Large lobe-like thickenings are found in intercolpar and polar areas. 

 These are distributed symmetrically, two on each intercolpar face and one on 

 each pole. In terms of the layers of the ektexine, this thickening is chiefly re- 

 flected by a widening of the outer ektexine (fig. 101 C), although the inner ekte- 

 xine is also thicker in these areas. In addition to these prominent emergences, 

 numerous minute spines are present on the unthickened areas of the exine. Pollen 

 of D. tatei is further distinguished from that of D. pinifolia in that the shape of 

 the grains is basically subprolate. 



FIG. 100. Duidaea pinifolia; A, pollen grain; B, optical section of grain at equator, C, 

 section of inner ektexine tangential to grain surface. FIG. 101. Duidaea tatei; A, pollen 

 grain; a germ pore is shown at extreme right; B, optical section of grain at equator; dotted 

 line, above, indicates outline of an intercolpar thickened area below the plane of the 

 optical section; C, longitudinal optical section of grain, showing a thickened area 

 such as is indicated at lower left in A. Figure 100, X 1000. All others, approximately X 

 800. Specimens represented are listed in table 1. 



