494 Fr. J. Mathiesen. 



b. Rosette- or semi-rosette piants: Pediciilaris spp. 



1. With Runners: P. lapponica and P. capitata. 



In P. lapponica the runners are most frequently mono- 

 podial, and during a limited number of grow-th-periods they 

 form few-leaved rosettes at their apex, Nvhile the floral 

 shoots, Nvithout any preceding vegetative stage, arise later- 

 ally on the rosette-axis. Sometimes the runners may ter- 

 minate their growth by the formation of a floral portion. 

 Floral shoots may also arise laterally on the basal portion 

 of older shoots of the same kind, so that a small rhizoma 

 multiceps is developed. 



In P. capitata the runner terminates its growth after a 

 vegetative period of 1 — 3 years, by the formation of a floral 

 portion, often without foliage-leaves (a peduncle). 



The \^^nter-buds of both species are protected by seale- 

 leaves. Adventitious roots are developed and vegetative 

 reproduction takes place. 



In the Arctic regions P. lapponica (and certainly alsa 

 P. capitata) requires a snow-covering during its winter-rest. 



2. Without Runners: P. sudetica, eiiphrasioides, Scep- 

 triim carolinum, hirsuta, lanata, flammea and Oederi. 



All these species have a short vertical rhizome ("meso- 

 corme", E. Warming^); with reference to the duration of 

 the main root, they may be divided into two groups, a& 

 stated by E. Warming (1890, p. 206 et seq.), viz., those in 

 which it is of long duration, a faet connected with its vigour^ 

 and often rather copious branching (P. euphrasioides, hir- 

 suta and lanata), and those in which it is of short duration 

 {P. flammea and Oederi^ to which may be added P. sudetica 

 and Sceptrum caroliniim). 



1 E. Warming, 1918: Om Jordudlobere (Underground Runners). 

 With a resumé in English. Kgl. Danske Vid. Selsk. Skrifter. 8. Række. 

 II. No. 6. 



