Bd.2 • DANSK BOTANISK ARKIV • Nr. i 



UDGIVET AF DANSK BOTANISK FORENING 



— 1914 = 



Studies in the genus Entorrhiza C Weber. 



By 



C. Ferdinandsen and Ö. Winge. 



I. The spore formation in Entorrhiza digitata Lagerh. 



A. rich material belonging to this species was benevolently- 

 sent to us by professor G. Lagerheim in Stockholm. It was 

 fixed in chrom-acetic acid and very well preserved so that micro- 

 tome cuts, which were stained with Heidenhains hematoxyline, 

 proved good objects for a closer study of the spore formation. 

 The three spore forms as they are described and figured by 

 Lagerheim were found mixed together (cfr. our figures 1, / — n 

 from Danish material), viz. l ) some very coarsely and unevenly 

 warted, 2 ) some others lower and more evenly warted, while 

 3 ) a third form of spores were entirely smooth and very thick- 

 walled. The shape was always exactly globular and the size varied 

 near 18 y. in diameter, some few however reaching 30 [x or more 

 across. 



Already P. Magnus (1878) and C. Weber (1. c.) state that 

 the spores in Entorrhiza are formed apically on screw-shaped 

 »sterigmata«, and Weber figures these organs in E. Aschersoniana, 

 while P. Magnus gives a picture from E. cypericola, a copy of 

 which is found in our fig. 8. Using the highest power of the mi- 

 croscrope, however, we saw that the spores in E. digitata are 

 formed not on a single »sterigma«, but as a rule by joining of 

 two. The most common case is figured in fig. l,a, where the two 

 spore-forming filaments are seen like somewhat screwed strings 

 adhering to the ripe spore. In some successful slides we happened 

 to see that the spore no doubt is formed by the working-together 

 of two spiral filaments twining around each other, and that the 

 outside walls of the filaments simply are continued into the spore- 



Dansk Botanisk Arkiv, Bd.2. Nr. 1. 1 



