ON NAIAS GRAMINEA DEI., VAK. DELILEI MAGNUS. 



25 



characters of the Eeddish plant agree with the description of 

 Z. repens in essential points, but the stigma is not usually more 

 enlarged than in Z. palustris, whereas this feature is a decided 

 character, both in the diagnosis and in Eeichenbach's plate.* In 

 the spring and early summer it has large reserve-buds, of the size 

 of peas, from which the shoots take their rise. 



One of its peculiarities is, that it has four or five rows of spines 

 or protuberances on the ' dorsal and ventral edges of many of its 

 carpels, and much more prominent than they are in Z. pedunculata, 

 Z. gibberosa, and Z. polycarpa. 



Delile reports t finding Zannichellia palustris in a lake near to 

 Fareskour in Lower Egypt, along with Naias muricata. It would 

 be interesting to determine whether the form is the same as that 

 which occurs in the canal at Eeddish. Local botanists also ought 

 to keep an eye upon the possible occurrence of the rare Naias 

 muricata, figured and described by Delile ; so far it has only been 

 recorded for Egypt and Arabia. 



The locality which produces such an extra-anglican species as 

 Naias graminea must be worth exploring for the animal life which 

 is fostered by the same high temperature which has sustained the 

 Char a and the Naias. 



XVII. — Geographical Distribution. 



Naias graminea is distributed over a wide area. It occurs in a 

 natural state in the northern and central parts of Africa, in Syria 

 (Plain of Sharon : ' Memoirs of the Palestine Exploration Fund,' 

 Fauna and Flora, p. 416), and Persia, in the Indian Archipelago 

 and other warm regions of Asia, and probably in Japan. It does 

 not occur in Europe except as a colonist, it having been introduced 

 (according to the Italian botanists) with East Indian rice, into 

 districts where that cereal is cultivated, as in the plains of 

 Lombardy and. Venice ; the Italian localities are given in Cesati's 

 ' Compendio della Flora Italiana,' as Alagna- in Novara, Balzola 

 between Vercelli and Casale, Merlato near Milan, Upper Ver- 

 cellese, Strasoldo nel Friuli near Palmanavo. It has also been 

 reported from the extreme north-eastern portion of Austria; but 

 it is not native in any of its European stations, and it is an 

 introduction in Lancashire. It becomes, therefore, an interesting 

 question to account for its appearance in a country which does not 

 grow the rice which it consumes. 



XVIII. — Its probable Source of Origin. 



When this plant was exhibited at the British Association at 

 Southport, in September last year, I expressed the opinion in the 

 Biological Section, that it had. probably been introduced into the 

 Eeddish locality with Egyptian cotton. This class of cotton is not 

 one of the staple articles of consumption in the Stockport district, 



* Ioones Floras Germanics, &c, vol. vii., fig. 20, pi. xvi. 



f ' Flore de l'Bgypte,' vol. ii., p. 281 ; and also on page 75 under No. 872. 



