BOTANY 
THE STONEWORTS (Characea)' 
The Charas or stoneworts constitute a well-defined group of aquatic 
plants, the English appellation being given to them on account of the 
quantity of lime that is secreted by some of the species. They are 
always submerged, and are to be found in ponds, pools, lakes and streams, 
affecting chiefly quiet waters, although sometimes occurring in rapidly 
running brooks. They are often the first kind of vegetation to occupy 
pools that have been newly formed, such as water holes in clay pits and 
reservoirs that are uncovered. In such situations they may sometimes 
be observed to have filled nearly the whole of the available space, to the 
temporary exclusion of other vegetation. It is also noteworthy that they 
occasionally die away rapidly from an apparently congenial habitat, and 
although they may have fruited abundantly, and the mud below con- 
tains multitudes of their fruits, they do not reappear for several years. 
Apparently they have exhausted the constituents in the water that are 
necessary to their existence, and do not start a fresh growth until the 
conditions are again favourable for that purpose. It may happen that, in 
the meantime, other aquatic plants, such as water-buttercups and pond- 
weeds, have occupied the site, and the Characee can only find a pre- 
carious existence, or fail to reappear for an indefinite period. In the 
waterways of the Fen districts they often occur in enormous quantities, 
and as their tissues contain a large proportion of mineral matter, they 
add annually in their decay an appreciable amount of soil. Their 
presence may often be detected by the fcetid odour they exhale when 
left uncovered by receding waters. 
The only two forms mentioned by Abbot (1798) are Chara 
vulgaris and C. tomentosa, the latter probably that now known as 
C. hispida. ‘The most noteworthy record given below is that of Nite//a 
mucronata, found in 1882 by C. H. Davis, after having been unrecorded 
in Great Britain for fifty years. 
° 
Chara fragilis, Desv. Frequent Tolypella glomerata, Leonh. Rare; Lea- 
var. Hedwigii. Leagrave, Sundon grave, near Bedford 
» capillacea. Totternhoe — intricata, A. Br. Rare; Brammingham, 
— contraria, Kuetz. ss Sundon 
— hispida, L. Not common Nitella mucronata, Kuetz. Rare; River 
— vulgaris, L. Frequent Ouse, Bedford, River Ivel, Sandy 
var. longibracteata. Buscot — opaca, Ag. Frequent 
ALG * 
Practically the only available information concerning the freshwater 
alge is in Abbot’s records. A few microscopists have examined speci- 
mens from time to time but have kept no records, and apparently have 
had no means of determining species. Mr. E. M. Holmes, curator of 
the Museums of the Pharmaceutical Society of Great Britain, has been 
1 By James Saunders, Luton. ; : 
2 Revised by E. M. Holmes, curator of the Museums of the Pharmaceutical Society of Great 
Britain. 
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