LYTHRACEyE 79 



on old walls, and is certainly a naturalised plant. It 

 is quite likely that further investigation may reveal 

 it in natural surroundings, in which case there would 

 be nothing in its geographical distribution to prevent 

 it from being reckoned as a native of Britain. 



Sedum stellatum, L. Native of rocky places in 

 Southern Europe. Cultivated in gardens, and occa- 

 sionally occurring on walls and banks in their 

 neighbourhood. 



Sempervivum tectorum, L. Apparently native on 

 rocks in Southern Europe. Known from ancient times 

 as an introduction in the northern part of the Continent 

 and in England, growing on roofs and walls. 



LYTHRACE^. 



Lythriiin Graefferi, Ten. Very common in wet 

 ground in some parts of the Mediterranean area. It 

 has been recorded several times from waste ground 

 in England, but as yet no definite clue as to its origin 

 has been afforded. 



[Lythriiin Hyssopifolia, L. Native in wet places 

 throughout Europe, including probably some parts 

 of England. It is, however, a species which has been 

 known to spread very rapidly in waste places far 

 from its native range, as for instance in Australia 

 and New Zealand, where it has become locally abundant. 

 It may perhaps belong to the numerous class of grain 

 casuals, for it occurs in cultivated fields in the east 



