1957] 



ANATOMY OF GUAYANA MUTISIEAE 



471 



Duidaea. 



Portions of a flower of Duidaea tatei are shown in fig. 114. The corollas of 

 this species (fig. 114A) exhibit the simplified type described above for Gongylo- 

 lepis fruticosa. Although the five corolla- tube veins continue into the achene, 

 fewer than five additional exterior bundles may be present (fig. 114 C, E). Stamen 

 traces unite with the associated corolla veins in the corolla-tube. In the style 

 (fig. 114 B) four bundles are present. The dorsiventral pair of these unites with 

 achene wall bundles in the achene summit. In the flower studied, only one of the 

 lateral bundles was seen to form an interior bundle in its extension into the 

 achene. A simple ovule trace is present, and all of the bundles in the achene 

 unite at the base into a single strand. Duidaea pinijolia was found to have a 

 vasculation pattern like that shown for D. tatei. 



Achnopogon. 



The corolla of the monotypic genus Achnopogon (fig. 115 A), like that of 

 Duidaea, has a simplified venation. In the achene, the full complement of ten 

 bundles is present, half of them continuing upwards into the corolla-tube. Stamen 

 traces unite with the corolla-tube bundles in the achene top. In the style of 

 Achnopogon (fig. 115 B), as in that of Duidaea tatei, four bundles are present, the 

 lateral two uniting with the dorsiventral pair at various points along the length of 

 the style. Rather than joining with exterior achene wall bundles, however, all four 

 continue into the achene as interior bundles, (fig. 115 E). In the achene illustrated, 

 one of the lateral interior bundles is double along part of its extent. At the base 

 of the achene, the dorsiventral pair of interior bundles unites with nearby ex- 

 terior bundles, while the lateral interior bundles and the ovule trace unite as a 

 central plexus; this plexus joins, further down, with the single strand formed by 

 the union of all of the exterior bundles. 



Glossarion. 



Flowers of the monotypic genus Glossarion (fig. 116) are of particular interest 

 in that they are ligulate in form, all the lobes being united except at the tips 

 (fig. 116 A-C). Although the lobes are histologically united, the vascular anatomy 

 suggests that the corolla form is basically actinomorphic, with some degree of 

 modification. As the corolla in figure 116 A shows, some of the lateral veins 

 unite beneath the short sinuses at the "ligule" tip. It seems significant, how- 

 ever, that each of the five veins of the corolla- tube divides into two laterals at 

 the same level as the vein beneath the single deep sinus in the corolla. Portions 

 of two otner corollas are shown (fig. 116 B, C) to indicate the variation in vena- 

 tion at the corolla tip. In each of these, however, ten laterals are present in the 

 more basal portion. Occasionally one of the outer lobes may be separate for a 

 short distance (fig. 116 B). The vascular pattern of the corolla, then, shows little 

 modification from an actinomorphic form, although the tissues between these 

 lobes are continuous. This is a stage in union of corolla lobes beyond that found 

 in Fitchia (Carlquist 1957b), where sinuses are histologically formed between the 

 lobes, although only the adaxial sinus usually opens during anthesis. Stamen 

 traces unite with their associated corolla bundles in the achene top. In addition 

 to the five exterior bundles, which continue into the corolla, five additional 

 bundles, terminating at the achene summit, form the complement of ten exterior 

 achene bundles (fig. 116 E). The style of Glossarion (fig. 116 D) contains four 

 bundles, uniting to two above. These four bundles continue downward into the 

 achene as interior bundles. Occasionally one of the dorsiventral interior bundles 

 may unite with a nearby exterior bundle (fig. 116 H). The lateral pair, however, 



