Rosaceæ. 63 



with racemose shoot- structure, citing as additional examples 

 Cassiope tetragona and Empetnim; and on p. 33 he says that 

 there is a clear distinction between vegetative or vegetative- 

 floral short shoots and vegetative long shoots. In Lapp- 

 mark where he was staying the long shoots measured 2 — 4 

 cm,, and had spirally arranged leaves in the axils of 

 which short shoots developed even during the same year. 

 AscHEKSON and Graebner^ ascribe to D. octopetala a long and 

 much branching stem with prostrate long shoots and numerous 

 erect short shoots. — The results of my investigations of 

 Dryas octopetala and D. integrifolia are in several respects 

 different from those arrived at by Haglund. 



The same year in which a shoot flowers it produces a 

 small number of usually close-set lateral shoots, as generally 

 only the upper leaves subtend shoots. At first the shoots 

 have a scale-leaf, afterwards foliage-leaves follow. In vigo- 

 rous and luxuriant plants the shoots are usually distinguished 

 into short shoots and long shoots, which otherwise behave 

 as described by Ascherson and Graebner. In investi- 

 gating shoot-apices in plants both in the Botanic Garden in 

 •Copenhagen and in the alcohol material, small flower-buds 

 were as a rule found on all shoots gathered in the autumn; 

 when such were absent the shoots were frequently weak short 

 shoots. Fig. 25 shows a longitudinal section through a 

 flower-bud gathered in August in Greenland; the stamens 

 have just been developed and there are indications of the 

 outermost carpels. The young flowers in the Botanic Garden 

 in Copenhagen had in January developed so far that the 

 stamens were externally fully developed, but in the carpels 

 no ovules were formed. Probably the development is not 

 so advanced at the same time in colder regions where the 

 flowering period also occurs later than in Copenhagen (see 



' Synopsis d. mitteleurop. Flora. VI, 1, pp. 889 — 90. 



