1859.] MURAL PLANTS. 49 



in its yellow vest, diffuses its sweetness all around. Not so 

 agreeable its sulphur-scented relative Sinapis tenuifolia, an un- 

 frequent companion on the wall. This plant grows very readily 

 from slips in any garden-soil, but does not mature its seed there 

 as it does on the wall. Geranium lucidum, Co?'ydalis lutea, C. 

 claviculata, Draba verna, Parietaria officinalis, and the ferrugi- 

 nous Saxifraga tridactylites, Arenai'ia serpyllifolia, Cerastium 

 viscosum, C. semidecandrum, all denizens of the wall. Lactuca 

 muralis leaves its woodland shades, to perch upon the wall. For 

 a mural Flora none excel the Sedums ; enduring, hardy plants, 

 particularly Sedum acre, come from the hills to spread on our 

 walls and roofs its cloth of gold. Sedum reflexum and C. album, 

 are welcome guests, their corymbs studded with silver and gold ; 

 and Sedum dasyphyllum, a little chubby favourite, delights to sit 

 upon the wall. Sempervivum tectorum, rising in columnar ele- 

 gance from amongst its infant progeny, crowned with a diadem 

 of floral gems, subsisting on ethereal food, is a rich addition to 

 our mural Flora. 



Some of the cryptogamic tribes migrate to our walls and 

 buildings, especially Ruta-muraria, properly named, which abun- 

 dantly fringes the upper parts of our garden-walls. Grammitis 

 Ceterach cannot colonize so successfully. Polypodium vulgai'e 

 abounds, and occasionally Aspidium Filix-nias and Adiantum- 

 nigrum appear on walls. Plants even will get into difficulties, as 

 well as men. I once observed a plant of Scolopendrium vulgare 

 springing from a small fissure in an over-burnt brick in a wall. It 

 lived there about six years; it produced a very small frond annually, 

 not half an inch long ; at last, tired of its incarceration, it died. 



Procreative nature spreads abroad her redundancy of seed, 

 and where it falls it will vegetate, however inimical the situation 

 may be to its prosperity. 



Hieracium sylvaticum is often to be found on walls. To this 

 plant the term murorum would be more suitably applied than to 

 the plant now called Hieracium murorum, which I never saAv 

 growing on either walls or rocks. They both are found growing 

 together plentifully in our native woods, different in habit and 

 structure; but a novice in botany, by a little attention, may 

 easily discriminate the difference in the two plants. Very pro- 

 bably those two plants were once considered identical, at a time 

 when less acumen was observed in botanical science. The at- 



N. S. VOL. III. H 



