909 



3. Vegetative ppopagation and structure of the shoots. 

 The hapaxanthic species propagale by seeds alone, whereas 

 many of the perennials propagate both by seeds and vegetatively. 

 It will be of interest to examine which species and how many of 

 them possess both modes of propagation. In the Hst pp. 896 — 902, 

 abbreviations are given relative to the vegetative propagation of the 

 perennial species in the Færoese flora. I have dealt with them 

 linder three categories: 



1. Spot-boiind (sedentary) species, i. q. species, which have 

 no stolons, creeping rhizomes nor bud-producing roots, or the rhi- 

 zomes are so short that the piants have little, if any, power of 

 wandering vegetatively. 



2. Wandering species with epiterrean (above-ground) 

 runners. 



3. Wandering species with subterrean shoots: stolons, 

 creeping rhizomes or bud-producing roots. 



In preparing this part I have used the excellent paper by E. 

 Warming (1884) on the structure of the shoots, hibernation and 

 rejuvenescence. The reference of the species to one of the three 

 categories is based on this same paper, on Raunkiær's book on 

 the Danish Monocotyledons (Raunkiær 1895—99) and on my own 

 researches. In many cases it has been difficult to decide whether 

 a species with only a slight power of wandering should be taken 

 as spot-bound or as wandering; my decision will be seen as regards 

 all the species in the list. Some of the spot-bound species have 

 another kind of vegetative propagation, viz. the power of producing 

 bulbils or hibernacles, but as this phenomenon falls from a biolo- 

 gical point of view nearer to that of propagation by seeds, I have 

 kept the species in question among the spot-bound. They are the 

 following: Aira alpina, Festitca ovina, Lycopodiiim selago, Poa alpina, 

 Polygonum viuiparum, Potamogeton piisillus, Sedum villosum and 

 Utricularia vulgaris. The following also fall naturally among the 

 spot-bound since they produce bulbils exceptionally : Cardamine 

 pratensis, Drosera rohindifolia, Malaxis palndosa and Saxifraga stel- 

 laris. 



Of the 269 perennial species not less than 151 (56 p. cent) are 

 spot-bound, while 118 (44 p. cent) have wandering power; of the 

 latter 42 (16 p. cent) have epiterrean runners and 76 (28 p. cent) sub- 

 terrean wandering shoots. The percentage-figures are much the 

 same, if we consider only the species of commoner occurrence in 



