50 B Canadian Arctic Expedition, 1913-18 



abundant in clearings and newly burned lands. It is also called Willow-herb 

 on account of the seeds bearing a tuft of long hairs through the help of which 

 the plant is readily disseminated over areas of great extent. However, the 

 species possesses also another means by which its dispersal is effected, namely, 

 by the long horizontal roots developing root-shoots; these roots with buds 

 may persist for many years in the soil in a dormant state waiting for the oppor- 

 tunity favourable to their farther development. And this opportunity is the 

 cutting down or burning of the forest. This is a fact so well known that it is 

 hardly worth mentioning but, among the many reports that have been given 

 about the sudden and abundant appearance of the species, one might be cited 

 here which is quite interesting. Mr. I. W. Chickering ^ writes: "In northwestern 

 Maine, on a tract of land of some 4,000 acres, over which lumbering operations 

 had been carried on some years ago, leaving a tangled mass of limbs and under- 

 brush a fire broke out June 8th and swept over this entire tract, lasting for two 

 weeks, burning with such fury that it was almost impossible for the stage to 

 travel along the road. A new vegetation began to start in three weeks after the 

 fire, and the whole region of 4,000 acres was covered with Epilobium angusti- 

 folium as far as the eye could reach, over hill and valley, ridge and interval was 

 one mass of colour from the Fire-weed." This sudden and so abundant appear- 

 ance of the plant must necessarily have been caused by the rapid development 

 of root-shoots, which thus were in the soil in the state of buds waiting for the 

 opportunity. From the writings of Irmisch * we have learned about this plant 

 that it often reaches the flowering stage in the first year. But, of course,. the 

 vegetation mentioned by Mr. Chickering could not possibly owe its appearance 

 to seeds, three weeks after the fire. But Irmisch describes also the root-system, 

 and this author made the interesting observation that the primary as well as 

 the secondary roots of the young seedling develop buds freely which sometimes 

 give rise to new plants in the succeeding year. The wide distribution in the 

 north of the species evidently depends 'on its dissemination by the wind; its 

 persistence, on the other hand, it owes to the development of root-shoots. 



UMBELLIFERAE. 



Bupleurum americanum C. et R. 



The only arctic representative of the genus and in no particular morpho- 

 logically distinct from its numerous,' more southern, congeners among the 

 perennial forms. The primary root persists as a relatively slender tap-root 

 crowned with a rosette of long, narrow leaves and a few or only a single flower- 

 bearing stem, somewhat taller than the leaves; the tallest specimen measured 

 about 14 cm. in height. 



Selinum cnidiifolium Turcz. 



A few flowering specimens of this very conspicuous plant were collected on 

 Herschel island; it shows the same habit as Pachypleurum, but is more robust, 

 the stem taller, about 20 cm., and the ample, baisal leaves deeply cut; the largest 

 umbel me3,sured 10 cm. in diameter. 



ERICACEAE. 

 Ledum palustre L. 



In all the specimens collected the leaves are remarkably short, sometimes 

 barely 1 cm. in length, and very narrow; the inflorescence is also much smaller 

 than in the typical plant. Some of these specimens may be referable to the 

 variety decumbens Ait., but in others the stems appear to have been erect, and 

 attaining a height of about 23 cm. 



» Bot. Gazette, Vol. 9, p. 193. Chicago, 1884. 

 * Botan. Zeitung. Leipzig, 1857, p ■ 459. 



