176 ENGLISH BOTANY. 



I have seen neither Scotch nor Irish specimens, but Professor 

 Babington and Messrs. Groves have it from both these countries. 



England, Scotland, Ireland. Perennial. Summer. 



Stems slender, flexible, 6 to 18 inches long or more; "often 

 annularly encrusted" (Groves). Branchlets J inch to 2 inches long ; 

 nucules minute, yellowish, ultimately black. 



[The variety crassa (Braun, Rabenh. and Stiz. Exsicc. No. 101), 

 distinguished from the type by its greater stoutness and shorter 

 terminal segments ; and variety nidifica (Wallm. in Kongl. Yet. Akad. 

 Handl. Stockh., 1854, p. 262), which has the sterile branchlets often 

 simple, and the fertile branchlets very short and collected into com- 

 pact heads ; — are stated by Messrs. H. and J. Groves (Journ. of Bot., 

 1883, p. 22), both to have been found in Perthshire; the former in 

 Watson Loch, Doune, and Marlee Loch ; the latter in Marlee Loch.] 



There can be little doubt that the name " flexilis " was intended by Linnaeus to 

 include under it other forms besides the present, and it would have been much better 

 to have adopted some later but more specially applied name ; but " flexilis " is now in 

 general use, so that little confusion is likely to occur. 



Flaccid Nitella. 



SPECIES II. (?) NITELLA SYNCARPA. CkevaUier. 



Plate 1900. 



Dioecious. Bright green or olive. Stem slender, translucent, with- 

 out cortical cells or spine-cells or stipule-cells. Branchlets usually 6 

 (more rarely 7 or 8) in a whorl; those of the primary whorls in the 

 male plant elongated and forked or trifid, in the female simple, forked 

 or trifid, with acute but not mucronate 1-celled rays. Primary 

 whorls always lax ; those of the secondary whorls usually more 

 compact, and in the female plant always so, often so short as to appear 

 capitate. Nucules 2 or 3, rarely 4, at the middle of the simple 

 branchlets, or in the angle between the rays when they are forked, 

 without bracts, subglobular-ovoid, 5- or 6- (rarely 7-) striate, with a 

 minute deciduous crown. Globules at the angle between the rays of 

 the branchlets. 



Var. a. genuina. 



Braun, Rabenh. & Stiz. Char. Europ. Exsicc. No. 76. 

 Nordst. & Wahlst. Char. Scand. Exsicc. Nos. la, lb, and 2. 



