FLORINITES 



57 



the bars of the reticulum which may be 

 extended as much as 2 or 3 microns away 

 from the membrane surface. The body 

 wall inside the bladder is everywhere thin, 

 oftentimes less than a micron, and shows 

 no structural differentiation. Because of 

 its tenuousness, it may not be exosporal 

 in nature although it would seem rather 

 precisely equivalent to the thicker and 

 presumably exosporal body wall of Endo^ 

 sporites. The body wall of Florinites is 

 slightly less translucent than the bladder 

 due in considerable part, at least, to its 

 rather numerous folds. 



Affinity. — Florinites is known to be re- 

 lated to Cordaianthus (pars), Lehachia, 

 Ernestiodendron and Walchianthus 

 through the investigations of Florin 

 (1936, 1938-40); thus it seems evident 

 that it represents a part of the upper Pale- 

 ozoic gymnospermic alliance. 



That some cordaitaleans possess pollen 

 grains of the Endosporites type is shown 

 by Cordaianthus cf. C. shuleri Darrah 

 represented in collections made by Wilson. 

 Similar pollen grains are shown by Oliver 

 (1940) to be present in the pollen cham- 

 ber of ''Stephanospermum" caryoides 

 which, according to Florin (1937, p. 310), 

 is no doubt a cordaitalean seed. Oliver's 

 figures 40 and 42 show a characteristic, 

 and no doubt functional, trilete apparatus. 

 Florin's study o{ Cordaianthus saportanus 

 pollen and pollen grains of Florinites 

 type associated with it (his Cordaianthus 

 sp. 1 and 2) indicates that the suture was 

 entirely absent and the trilete marking 

 completely vestigial. In the walchian 

 conifers not even a vestigial remnant of 

 the haptotypic marking has been reported 

 but it might be present (just as in the 

 Cordaianthus sp. 2) and still not be easily 

 demonstrable from coalified compression 

 material. The agreement in pollen struc- 

 ture between the Cordaianthus material 

 studied by Florin, and his walchians is 

 such as to leave little doubt that a direct 

 relationship exists between them. Just 

 how this relation evolved and should be 

 systematically expressed cannot now be 

 stated. The pollen structure is so spe- 

 cialized, particularly when compared with 

 the expression of spore characteristics 

 elsewhere in the plant kingdom, as to per- 

 mit no conclusion other than direct re- 

 lationship. The possibility of convergent 

 evolution being responsible for the struc- 



tural similarity in the two instances is 

 entirely remote. 



These gymnospermic groups, often- 

 times regarded as distinct, thus have a 

 community of relationship which is mea- 

 gerly expressed for the present in the 

 genus Florinites. The probability is that 

 this group will also be of continuing value 

 for classification of these spores. If 

 plants of the cordaito-coniferous type 

 were partially restricted to upland habi- 

 tats their pollen grains may offer the only 

 widespread available record of their ex- 

 istence. For this reason it is essential 

 that they be classified as precisely as pos- 

 sible. 



Florinites is also related to Endospo- 

 rites, Pityosporites, Alisporites, and Para- 

 s pontes, all of which have the character- 

 istic bladder-forming perisporal (?) mem- 

 brane. The study of these in conjunc- 

 tion with fructifications and other organs 

 with which they are more or less definitely 

 correlated cannot fail to add greatly to 

 our knowledge of gymnospermic phylo- 

 geny during a critical period in the evo- 

 lution of this plant group. The defini- 

 tion of the age at which these genera are 

 first recognizable will be of geologic as 

 well as botanical significance. 



Remarks. — This genus is proposed to 

 apply to gymnospermic plants whose pol- 

 len generically corresponds with the type 

 species as expressed, in general, by the 

 foregoing definition. Florin has given 

 rather similar data in description of the 

 species ''cordaitiformis" which he places 

 under the genus name Pollenites (see be- 

 low). There is little doubt that such a gen- 

 eric designation is inadequate but question 

 may arise concerning the validity of the 

 specific epithet. 



Pollenites cordaitiformis was estab- 

 lished to include pollen which elsewhere 

 in his monograph Florin had assigned to 

 five other species of plants. The only 

 illustrations given to validate the name 

 had also previously been allocated differ- 

 ently to the other five species. Florin's 

 photographs still serve as an excellent 

 basis for discussion of the character of 

 isolated Florinites pollen but none of 

 those he illustrated are properly identified 

 with this genus because no single organ- 

 ism can have more than one valid name. 

 Specimens properly assigned to Lehachia, 



