125 



cimens are, as a rule, oftener met with in the interstices of the 

 slabs of liniestone than on the knolls. The individuals can reach 

 a great age. 



In the early stages of their growth. the shoots of P. fniticosa are 

 thin, long and straight, but, låter on, the individuals become bushier. 

 The yoiing. light internodes possess larger stipules. Fig. 3 shows 

 a specimen which is trailing along the surface of the ground. The 

 individuals of this species sometimes get this peculiar appearance 

 where the limestone-slabs are covered with gravel. 



The factors reducing the transpiration in the case of this species 

 — the form of the surface of the leaves. the revolute margins of 

 the leaves and the hairiness — are subject to great variations. I 

 have observed all transitions, from individuals with large. broad, 

 almost flat, green leaves with relatively sparse hairiness to individ- 

 uals with small, narrow. pointed leaves covered with grey hairs, 

 and with the edges greatly turned down. I have met with individ- 

 uals varying in character, in the same kind of locality and even 

 in the same group of bushes. a fact that does not agree with what 

 Wolf states as to the connection between the hairiness and the 

 character of the locality where the specimen in question grows. 



FLOWERIXG AND FRUCTIFICATIOX. 



With respect to the period of flowering of the species growing 

 on the Southern ..alfvar" of Öland, the period of growth can be 

 arranged in the following four divisions, characterized by certain 

 predominant species: 



l:st. period: beginning of period of growth. to end of May in- 

 clusive. 



2:nd. June. 



3:rd. » July. 



4:th. * close of period of growth. from beginning of August 



inclusive. 



P. fruticosa flowers during the last three of these periods until 

 into October, and most luxuriantly. as a rule, during the last half 

 of June. As regards the great length of the flowering-period. this 

 species rivals or is surpassed by only a few other species from 

 this locality. such as Sagina nodosa for example. 



In this connection it may be mentioned. that the period of flower- 

 ing in Öland is, for many species, another and a longfr one than 



