212 ENGLISH BOTANY. 



8 to 10 in a whorl ; the 5 inner ones longer, and usually exceeding 

 the nucule ; those on the outside of the branchlet shorter, and those 

 at the upper nodes of the branchlet, which do not produce nucules, 

 shorter, and often rudimentary. Bracts in the male plant usually 

 shorter than in the female, and only 2 of them longer than the 

 others, which are sometimes rudimentary. Nucules in the axils of the 

 bracts, at 2 to 5 of the lowest nodes of the branchlet, oval-ovoid, 

 deeply 12- to 14-striate, with a prominent erect-spreading persistent 

 crown. Grlobules on separate plants from those bearing nucules, 

 solitary in the axils of the bracts, at several of the lower nodes of 

 the branchlets, [or rarely on the same plant and placed below the 

 nucules (C. tenuispina).] 



In lakes, ponds, and ditches, and more rarely in brackish pools ; 

 rather rare, but widely distributed, reaching from Cornwall and 

 Hants, north to Orkney and Shetland ; more common in Scotland ; 

 also more common in Ireland, where it extends from north to south of 

 the island. 



England, Scotland, Ireland. Perennial. Summer, Autumn. 



Stems slightly branched, slender, often capillary, 3 inches to 

 1 foot long, with the internodes usually rather distant. Branchlets 

 ^ to ^ inch long. The more spinous and condensed states resemble 

 0. crinita, but the stems are much more faintly striate from the 

 cortical cells being smaller ; the bracts and stipule-cells are usually 

 shorter and less spine-like, particularly the bracts towards the ex- 

 tremity of the branchlets ; the nucules are much more strongly 

 striate, and the whole plant is much more brittle when dry. The 

 stouter states of 0. aspera often much resemble small forms of 

 C. hispida, particularly its var. pseudocrinita, [as for example C. aspera 

 var. dasyacantha, A. Braun, in which the stem is densely covered 

 with long setaceous spine-cells] ; but the stems and branchlets are 

 more slender, the cortical cells smaller, and the plant is dioecious, and 

 usually of a much brighter green tint. 



C. tenuispina, A. Braun (Char. Europ. Exsicc. No. 74), is doubt- 

 less a monoecious form, [the hermaphrodite plant,] variety, or at most 

 subspecies, of C. aspera. 



[Occasionally the spine-cells are reduced to mere rudiments like 

 those of some states of 0. fragilis, from which it is then difficult to 

 distinguish this species. See remarks under 0. fragilis. 



One of the most marked forms is C.fallax, Ag., a small state in 

 which the spine-cells are papilliform, and the branchlets variously 

 ecorticate, sometimes having the lowest joint or joints clothed with 

 cortical cells, and the rest naked, and sometimes having all the joints 



