352 Floristik, Geographie, Systematik etc. 



bracteata, Galeottiana, panamensis and Maxonii. They occur from 

 the states Vera Cruz, Mexico to the Isthmus of Panama. One 

 of them is a nevv species. D. Maxonii is like D. bibracteata, but 

 easily distinguished from that species by its much broader, acumi- 

 nate leaves, the much shorter and thicker stipes of the fruit and 

 the absence of constrictions between the seeds. It is remarkable 

 for the bananalike fragrance of its flowers. 



A fifth species has been found in the material collected by 

 Oersted in Costa Rica and named D. Oerstedii. The fru its differ 

 from the fruits of all the other species observed in their larger 

 size, and the alternate arrangement of the seeds. The leaves differ 

 from those of D. panamensis in the indument of the midrib beneath, 

 which is densely fulvous hirtellous. The species is easily distin- 

 guished from D. Maxonii by its much shorter floral pedicels. It is 

 distinguished from D. bibracteata by the shape of the leaves. 



D. panamensis (Robinson) Safford, D. Maxonii Safford and D. 

 bibracteata (Robinson) Safford are illüstrated on the plates. 



Trigyneia Galeottiana Baillon also belongs to the new genus. 



Jongmans. 



Starr, A. M., A mexican Aytonia. (Botan. Gazette. LXI. p. 48 — 58. 

 PI. I-IV. 4 F. 1916.) 



The material was collected in Mexico. The species cannot be 

 determined definitely. Of the four mexican forms described by 

 Gott sehe, it resembles most closely his Plagiochasma crenulatum. 

 The description of the material is summarized as follows: 



Two appendages may be present on the ventral scales. Rhizoids 

 are absent among the first pairs of ventral scales. Old rhizoids 

 are often replaced by new ones that form within them. 



Fungi are prevalent in the compact tissue of the thallus. They 

 enter through the rhizoids and may also pass out through them. 

 No „pseudoparenehyma" was found. 



The secretion of mucilage seems to have nothing to do with the 

 „protection" of the growing point, but to be most pronounced about 

 the egg and the antheridia. 



Pitted cells show no tendency to become tracbea-like. 



The origin of air Chambers in the thallus and receptacles is 

 schizogenous. The horizontal increase in the size of the Chambers 

 is due to a tearing of the tissues. The pore of the Chambers of the 

 thallus and of the antheridia! reeeptacle is simple, but that of the 

 archegonial reeeptacle has an elaborate margin. 



The development of the sex organs follows the Marchantiales 

 type. The archegonia form early in the history of the reeeptacle 

 and parallel the increase in size of the reeeptacle by great increase 

 in length of the neck. Following fertilization an exceedingly mas- 

 sive venter is developed about the embryo. Five archegonia may 

 begin to develop on one reeeptacle, but no more than three come 

 to maturity. 



The conditions of the cells of the foot and of the adjacent parts 

 of the thallus indicate the parasitic nature of the sporogonium. No 

 elaterophore appears. Jongmans. 



Ausgegeben: SO November 1018. 



Verlag von Gustav Fischer in Jena. 

 Buchdruckerei A. W. Sijthoif in Leiden. 



