CALLITRICHE TEUNCATA. 157 



mention, as a further example of Borrer's accuracy, that among his 

 specimens of the Sussex plant, in the Smithian herbarium, now at the 

 Linnean Society, he has labelled one " C. pedunculata, DC. : I have it 

 from Sardinia under this name." As C. truncata is a common plant 

 in that island {teste Hegelmaier), it was probably that species which 

 Borrer received, and rightly identified with the plant from Amberley. 



The length of the fruit-stalk, on which some stress has been laid in 

 the genus, appears to be a character of veiy little importance in dis- 

 tinguishing this subspecies ; in Gussone's description, the lower fruits 

 are said to be considerably stalked, and the upper ones subsessile ; 

 Todaro's Sicilian examples have long fruit-stalks throughout, though 

 shorter to the younger seed-vessels. In the Sussex plants, as was noticed 

 by Borrer and correctly figured in the E. B. figure, all the fruits are 

 shortly stalked, whilst in the Normandy specimens they are very nearly 

 sessile, as is also, 1 am informed, the case in the plants from Algeria, 

 Veglia, and Santa Maura. 



I append a description of the Amberley plant, sufficient to distin- 

 guish it from the other British species or subspecies : — 



C. truncata, Guss. Plant entirely submerged, without stellate scales. 

 Leaves all similar, sessile, one-nerved, of a clear translucent green, strap- 

 shaped, from \-\ inch long, and about four to six times as long as 

 broad, not wider at the base, truncato-bifid at the apex. Flowers 

 naked. Stigmas reflexed-patent, caducous or sub-persistent. Fruit 

 shortly stalked, circular in outline, about -^ inch across, furrows between 

 each lateral pair of carpels very deep, reaching to the axis of the fruit, 

 which, when ripe, is thus nearly divided into halves ; carpels with a 

 blunt dorsal ridge not keeled or winged. 



When we remember how generally submerged aquatics are neglected 

 by collecting botanists, and, in consequence, how rare is a good series 

 of Callitriche in herbaria, we need not be surprised that no other 

 English station for C. truncata can be given. It is, however, scarcely 

 to be doubted that others exist, and the foreign distribution indicates 

 the neighbourhood of the sea-coast in the south and west of England 

 as their probable situation. According to Sowerby, the flowers are 

 produced in May. 



