24 B Canadian Arctic Expedition, 1913-18 



According to Warming (I.e. p. 255) "the primary root lives for a long time," 

 but in none of the very numerous specimens of the typical plant and the varieties 

 which I have examined was the primary root preserved. Characteristic of this 

 plant is the profuse development of long stolons with small scale-like leaves 

 and stretched internodes (Fig. E). 



These aerial shoots are ascending and the leaves are more or less crowded 

 on account of the shortness of the internodes. As pointed out by Kjellman i 

 the leaves are still attached to the shoots when the winter commences but they 

 are in a withered condition; the stems, on the other hand, remain alive and 

 persist throughout the winter. 



At the beginning of the spring small buds become visible in the axils of the 

 faded leaves which soon develop into small leafy shoots (Fig. E: 6-8). These 

 shoots frequently remain vegetative for one or two years until they become 

 terminated by an inflorescence or a single flower. In specimens from Port Ep- 

 worth the flower appeared already in the first season, as figured (Fig. E: 6). 

 We have thus in this species of Stellaria a very interesting example of herbaceous 

 aerial stems which winter over and produce axUlary buds the function of which 

 is to develop assimilating leaves, new axillary buds, and finally to produce 

 flowers and fruit. This method of reproduction I observed also in the alpine 

 plant in Colorado,^ but in this the axillary shoots frequently reach the flowering 

 stage already in the first year of their growth. 



Several other species of Stellaria exhibit this type of vegetative reproduc- 

 tion, for instance: S. longifolia Muehl., S. humifusa Rottb., and S. Holostea L. 



In S. crassifolia Ehrh. the withered stem-leaves subtend large buds, hibern- 

 acula, which winter over; they have been described by Norman', viz: "forma 

 gemmificans. Caules saepe steriles vel pauciflori. Rami gemma terminali, 

 compacta, saepius sordide violacea, ovato-globosa v. ovalia v. elliptica, usque 

 ad 5 m.m. longa, e foliis katalyticis, carnosis, brevibus, ovalibus, obtusis, densis 

 formata. Gemma sequen,te anno a ramo delapsa sensim elongatur, fibrillas 

 radicales ramosas plures ex omni axilla protrudit, demum in caulem procumben- 

 tem, internodiis longioribus gaudentem, se producit." 



Merckia physodes Fisch. 



The primary root was not preserved in any of the specimens collected. For 

 a comparison I have also examined material from Port Clarence, Alaska, from 

 Moosehide mountain near Dawson, Yukon, and from Jakutsk, Siberia. Subter- 

 ranean stolons are developed with minute gcale-like leaves and with stretched 

 internodes; capillary secondary roots develop freely from the nodi. The aerial 

 shoots are long, prostrate, very leafy, and while many remain purely vegetative 

 during the first season, some others develop a single, terminal flower; very 

 often a long vegetative branch may develop from the axil of one of the leaves 

 beneath the flower; thus it may look as if the flower were lateral but it is only 

 apparently so. The prostrate aerial shoots develop no roots in the first year 

 but in specimens which represented bases of old shoots roots were present, and 

 these basal stem portions had gradually become buried in the soil. Characteristic 

 of Merckia is thus the ability to wander not only by means of subterranean 

 stolons but also by means of the long, prostrate, aeriaLshoots. 



Cerastium alpinum L. 



This forms large cushions borne upon a deep but slender primary root 

 which branches freely. The numerous persisting stem-bases constitute a pseudo- 



^ TJr Polar vaxternaa lit. I.e. 



' Method of hibernation and vegetative reproduction in North American species of Stellaria. ' (Am 

 Journ. of Science, Vol. XXV. New Haven, 1908.) 



' Florae Arcticae Norvegiae species et formae (Christiania Vid. Selsk. Forhdl. Christiania, 1893, 

 p. 20.) 



