54 BRITISH CHAEOPHYTA. 



A marked peculiarity of C. as f era is the production from the 

 lower nodes of the numerous nearly spherical whitish bulbils, 

 which are very conspicuous when the plant is pulled up. These 

 are usually in clusters of 2 to 6, though sometimes solitary, and 

 attain a diameter of about 1"5 mm. The only other British 

 species known to produce similar bulbils are the allied C. desma- 

 cantha and Lamprothamnium papulosum, C. aspera does not 

 fruit very freely, and no doubt relies partly on this very efficient 

 method of reproduction. Dr. Giesenhagen {I. c.) has published 

 the results of a careful investigation of its root-bulbils and pro- 

 embryonic growth, with illustrations, two of which are repro- 

 duced in our Vol. I, p. 38. 



Var. b. subinermis. 



KiJTZiNG Sp. Alg. p. 521 (1849) ; Geoves, Exsicc. 32. 



(Plate XXXIX, fig. 8.) 



Spine-cells, stipulodes and bract-cells for the most 

 part very short and obtuse. Spine-cells often reduced 

 to minute papillae. 



In many of the counties enumerated for the type, 

 especially in Scotland and Ireland. 



Usually more slender and of weaker habit than the type, 

 often having elongated spine-cells on some of the internodes. 

 In its extreme form a distinct-looking variety, but connected 

 by intermediates with the type. 



Var. c. lacustris. 



H. & J. Geoves in Jom-n. Bot. XVIII, p. 129, t. 207, f. 4a (1880). 

 Exsicc. Gr. & B.-W. 36. 



(Plate XXXIX, figs. 9-11.) 



Stem very short, stout, internodes short, hranchlets 

 short, stout, strongly incurved. Spine-cells short, thick, 

 obtuse. 



Abundant in Lough Neagh, from vrhence it was 

 originally described, and in Lough Beg. Somewhat 

 similar forms, not so extreme, have been found in several 

 other Irish lakes. 



Growing in dense tufts, much resembling the var. annulata of 

 C. delicatula. 



