﻿Contributions to Japanese Characeae. — III. 



By T. F. Allen. 



A.-NEW SPECIES OF NITELLA. 



The following Japanese species of Nitella seem to belong, 

 properly, to the subdivisions diarthrodactylae , liomoeophyllae , mo- 

 noicae, snbflabcllatae, congestae, microsporae. This group, founded 

 on A r . axillaris A. Br. (from Caracas, S. Am.), is, in general, charac- 

 terized by a condensation of the fertile verticils in close spike- 

 like racemes (the new N. ngida, Saitoiana and Tanakiand); or in 

 dense axillary clusters (N. axillaris A. Br. and N. Morongii Allen). 



The group has been divided by Nordstedt into two: (i) With 

 small spores, 290 to 340 long, and (2) With large spores, 400 to 

 450 long ; the capitula of the latter are either terminal or axillary. 

 The species with smaller spores may be arranged as follows 

 (according to size of spore) : 250, N. Morongii Allen ; 275, N. Saito- 

 iana ; 285, N. rigida; 290, N. axillaris A. Br.; 306, N. Tanay 

 kiana ; of these N. rigida Allen bears fruit in elongated axillan 

 and terminal spikes ; N. Tanakiana Allen also, but the spikes are 

 rather like condensed upper verticils ; N. Saitoiana Allen has 

 more open upper fertile verticils ; while N. Morongii Allen bears 

 fertile verticils in dense axillary clusters. 



Nitella rigida sp. nov. 



Plants erect, strict, almost rigid, 15-20 cm. long; branches 

 strictly erect, not spreading, lower sterile leaves 4 to 6 in a whorl 

 6-8 cm. long ; divided near the apex into 3-5 short branches, 

 which usually are once again divided into two short terminals. 

 From the sterile verticils, long "spikes" of fertile leaves arise, 

 which may exceed the length of the stem ; the fertile verticils 

 are at first remote, but become crowded above; the entire 

 spread" of a fertile verticil is "scarcely more than 3 or 4 mm.; 



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5 in a whorl, are 2- ( 

 the first segment 54-60 'in diam.; the first node bears 5 divisions; 

 the second node carries 2 or 3 terminals ; the second segment of the 

 leaf is 45-60 in diam.; the terminals are about 25 in diam., rarely 

 3-celled and very rarely subdivided ; the ultimate cell is a mucro 

 15 at base bv 100 long; the obgonia are single at the node of the 

 leaf, tapered ; the oospore is 285 long by 272 broad, with five rarely 

 six, prominent, sharp ridges ; the membrane of the spore is cov- 



(73) 



