120 Lichenes. — Pteridophyten. — Floristik etc. 



morphologischen Veränderungen durch den Nähr- 

 boden bei Coniothyrium tirolense und Phyllosticta pirina. (Intern, 

 agr. techn. Rundschau, p. 834—835. VIII. 9. 1917.) 



Die verschiedenen Nährböden haben einen Einfluss auf die 

 Grösse und die Farbentönungen der Stylosporen von Coniothyrium 

 tirolense Bubäk. Auf gelatiniertem Biermost hat der jetzt Phyllo- 

 sticta pirina Sacc. genannte Pilz abgeteilte, schwach gefärbte Stylo- 

 sporen, was auf das Genus Ascochyta hinweist. Abgeteilte, durch- 

 sichtige Stylosporen zeigen sich in den Kulturen: Gelatinezusatz und 

 mit Aetznatron neutralisierter Zitronensaft. Die folgenden Genera- 

 tionen zeigten die gleichen Stylosporen. Aenderte man den Nähr- 

 stoff, so brachten die folgenden Generationen wieder ungeteilte 

 Stylosporen. In der Kultur, stets vor der Erzeugung der Stylospo- 

 ren, entstanden bei Phyllosticta „Makrosporioden", lange, querge- 

 teilte Sondergebilde in Keulenform, ähnlich den Konidien von 

 Macrosporium. Aehnliche Gebilde traf W. B. Mercer bei Phoma 

 Richardiae Merc, er schreibt sie aber dem Genus Alternaria zu. 



Matouschek (Wien). 



Thompson, J. McLean and R. Donaldson. The Ana tomy and 

 Affini ties of Platysoma macrophyllum, R. Br. (Trans. Rov. Soc, 

 Edinb. LI. 3. p. 631-656. 4 pl. 10 text figs. 1917.) 



In 1810 Robert Brown described a rare fern from Australia 

 to which the generic name Platysoma was grven; he noticed that 

 the plant was heterophyllic, possessing pinnate leaves suggestive 

 of those of Gleichenioid forms, and also small compressed filiform 

 leaves devoid of pinnae. This distinction was overlooked by subse- 

 quent systematists. Regarding the anatomy of the genus, relatively 

 little has been hitherto known. The present writers describe in 

 detail the results obtained by the anatomical study of a Single her- 

 barium specimen. They show that the stem stele is little removed 

 from the protostelic State. It consists of a continuous ring which 

 has never been seen to be broken by leaf-gaps or Perforation s. The 

 xylem is differentiated into two zones, the outer consisting of 

 smaller tracheides in the occasional parenchymatous groups and 

 chains, the inner of larger storage tracheides intermixed with paren- 

 chyma. Centrally lies a bulky pith surrounded by an inner endo- 

 dermis. The leaf-trace draws off from the outer zone of xylem as a 

 crescentic mass of tracheides, accompanied by an outer arc of 

 phloem. The leaf-trace remains undivided throughout, and the pin- 

 nation, except towards the tip of the leaf, is always of the extra- 

 marginal type. The sporangia are distributed solitarily upon the 

 lower surface of the pinnae and terminally on the veins. The 

 annulus is typically oblique, but is irregulär in position and in 

 Constitution. 



Platysoma is regarded as a type somewhat anomalous in its 

 characters. Like Cheiropleuria it shows sporangial advance with a 

 relatively primitive vegetative condition. There seems to be some 

 relation to the Gleicheniaceous type, but it is impossible to retain 

 the view of close affinity. Agnes Arber (Cambridge). 



Maebride, J. F., A revision of Mentselia, section Trachyphy- 

 tum. (Contr. Gray Herb. N. S. N° 56. p. 24—28. Dec. 31, 1918.) '" 



Four species are segregated. The following new names appear: 



