DISPERSAL BY WIND. 



821 



as their habitat narrow ledges in rocky places, it is inevitable that some of the 

 separated rosettes should fall over the steep wall, and should not come to rest 

 till they have travelled a considerable distance from the mother-plant. Roots are 

 soon developed from the base of the detached rosettes, by which they become fixed 

 to the substratum. Usually a parent plant produces 2-3 rosettes, but frequently as 

 many as six, and the neighbourhood of the terraces overgrown with the species 

 of House -leek figured, and with other allied species (Sempervivum arenarium, 



the true proportions of the offshoots. 



8. Neilreichii, S. Urtum) often looks as if it had been sown with the ball-like 

 rosettes, which have rolled down 



Sedum dasyphyllv (see fig. 454'), which grows in rocky crevices 

 niches of old stone walls, develops offshoot* partly in the floral and parUy ^n 

 foliage region. In the floral region the offshoots origmate by the *^* 

 floraf-leaves into foliage. Instead of flowers there are small rosettes fig. 464 ) 

 Z e, green scales, like those which take the place of flowers m 

 and 1 ce^ua (cf. P . 455). These rosettes in the autumn -k -y 



-ed eye It is em,dded in the 



