GYMNOSPEEMS— CORBAITALES— CORDAITES. 257 



GYA/ENOSPERIVIS. 



CORDAITALES. 

 CORD AIT AOE^E. 

 CORDAITES Unger, 1850. 



1822. Flabellaria Sternberg, Fl. d. Vorw., vol. i, fasc. 1, p. 32 (pars). 



1849. PychnophyUunt Brouguiart (uou K'einy), Tabl. d. Geu., p. 65. 



1850. Gordaites Unger, Geu. et Spec. PI. Foss., p. 277. 



The study of the structure of the plants long- known as Gordaites has 

 revealed an organization having- some of the characters of the Cycads, some 

 in common -with the Taxinecs, yet presenting an ensemble quite foreign to 

 either. Hence they have more recently been set apart as constituting- a 

 distinct family, which, while it may have been ancestral to other later types, 

 is without direct relation to any known living plants. 



Recognizing from the great diversity of fruits in the Carboniferous, 

 that can hardly have been produced by any other group of associated 

 plants, that several genera must exist in this family. Grand 'Eury divided 

 the original genus, as we have known it in our American literature, into 

 three genera, viz, Gordaites, Dorycordaites, and Poacordaites} Still another 

 type, Scutocordaites,^ was later differentiated by Renault and Zeiller, while 

 the discovery of a peculiar form in the Devonian of Pennsylvania about 

 the same time led to the description of a fifth genus, Dictyocordaites, by Su- 

 William Dawson.^ The characters of the leaves of these genera may be 

 briefly summarized as follows: 



Gordaites. — Leaves thick and transversely enlarged at the point of 

 attachment, simple, sessile, entire, lanceolate, spatulate, rounded at the 

 summit or obovate, 20 to 90 cm. long, usually very large, coriaceous, 

 traversed for nearly their whole length by fine, equal, or unequal parallel 

 nerves, which dichotomize several times. To this section or genus belono- 

 some of the species of wood described as JDadoxylon, Gordaioxylon, and 

 Araucarites or Araucarioylon, the bark, Gordaijloyos, the fragments of pith 



1 La flore carboniffere de la Loire, 1877, pp. 208-227. 



^Comptes Eendus, vol. C, 1885, p. 869; Fl. foss. bassin houUl. Commentry, pt. 2, 1890, p. 203. 

 'Amer. Jour. Sci., (3) vol. xxxviii. 18S9, p. 2; Canad. Rec. Sci., vol iv, 1S90, p. 2. 

 MON XXXVII 17 



