370 Fr. J. Mathiesen. 



between shoots from two opposite leaves, that the one 

 becomes vigorous and floral, and the other vegetative only, 

 is very common; it appears to be the rule that the shoot 

 which turns outwards towards the periphery of the tuft, 

 becomes more vigorous. It happens not rarely, however, that 

 the short, vegetative shoots are later on instrumental in the 

 formation of floral shoots, in that the latter arise as lateral 

 shoots upon them; in such a case the part of the parent- 

 shoot above these lateral shoots dies away, as is the case 

 in the floral shoot. The development of the lateral shoots 

 usually takes place in the second year of the parent-shoot, 

 and consequently simultaneously with the flowering. 



The Leaves are rather thick, entire or slightly serrate; 

 on the median rib and along the margin there is a sparse 

 covering of non-glandular hairs; such are also found on the 

 stem and in the floral region, viz., on the calyx and ovary. 

 In the Botanical Garden in Copenhagen the leaves on the 

 new innovation-shoots, developed during the last summer, 

 remain green and fresh during the winter; on the flowering 

 shoots, in my herbarium-material, the leaves from the previ- 

 ous year were withered in some cases; most often, how- 

 ever, they were green. 



As a rule, the basal portion of the shoots takes root 

 abundantly, and is drawn down by the roots to the surface 

 of the ground; in the individual illustrated in Fig. 1, which 

 has a somewhat more erect growth than is generally the 

 case, adventitious roots are only scantily produced; the roots 

 are developed at the earliest in the second year of the shoots. 



The basal portions of the shoots have growth in thick- 

 ness and may live several years; an individual from Greenland 

 (Ikalik) had a prostrate stock, 4 mm thick, which showed 

 16 annual rings. 



The Flower-biology has been investigated by H.Mul- 



