422 Fr. J. Mathiesen. 



p. 142; Poppius, 1903, p. 48; Sylvén, 1905, p. 88; Silen, 1906, p. 92; 

 Simmons, 1906, p. 34. 



Hemicrytophyte, with a primary root which dies away 

 rather quickly; it spreads by means of slender, subterranean 

 runners. As a rule, these are monopodial: their short ver- 

 tical portion bears leaf-rosettes, usually through a limited 

 number of growth-periods (1 — 3), the floral shoots arising 

 as lateral axes on the rosette-axis. 



As shown in Fig. 20, A and В the horizontal portion 

 of the runners has elongated internodes, with small scale- 

 leaves; in the axils of these, buds are formed which grow 

 out into new runners. New runners arise only in the hori- 

 zontal portion of the parent-shoot. The runners are provided 

 with adventitious roots, which must be described as "re- 

 stricted to one position only", inasmuch as they arise in 

 connection with the axils of the scale-leaves, as a rule one 

 at each. Haustoria were found on the roots. 



When the runner bends upwards, its internodes become 

 short, and the scale-leaves pass without intermediate forms, 

 into long-stalked foliage-leaves, of which it bears 3 — 7 in 

 the first year (at x in Fig. 20, A and В the dead stalks of 

 the rosette-leaves of the previous year are seen); at the end 

 of the season of growth a number of scale-leaves are again 

 formed, which function as bud-scales for the winter-bud. 

 Some runners pass over directly into their winter-rest, with- 

 out having succeeded in forming leaf-rosettes in the first year. 



Both the scale-leaves under the rosettes, and the rosette- 

 leaves, as well as the scales of the winter-bud, can subtend 

 buds (Fig. 20, Л, В and D); the lowermost buds must prob- 

 ably be regarded as reserve-buds; any true principal bud 

 does not occur. 



At the beginning of the next season of growth, one or 

 several — as many as 3 — of the buds can grow out into 



