1917-18.] BOTANICAL SOCIETY OF EDINBURGH 269 



from the same rhizomatous axis are several decumbent 

 non-rooting stolons some 18 cm. or so long which are 

 unbranched through about two-thirds of their length and 

 bear a few branches in about the upper third. Upon the 

 unbranched portion two regions are to be recognised — a 

 lower, which may be half the length of the whole, less 

 or more, is clad with small more or less elliptic straw- 

 coloured or brown withered leaves, the upper bears larger 

 green fresh leaves increasing in size upwards and with- 

 out interruption into the branched region where they 

 are larger than elsewhere. The limit between the lower 

 and upper regions of this unbranched portion is clearly 

 marked by the leafage, for at the point of junction the 

 leaves are particularly small often appearing almost as 

 scale-leaves; and then there is the contrast between the 

 withered and fresh leaves. The junction marks the limit 

 between the growth of two successive years. Each of 

 these stolons shows two years' growth. The leaves of the 

 first year's growth are withered, those of the second are 

 green and active and the portion of stolon bearing them 

 ends itself in a solitary flower and gives origin from the 

 leaves immediately beneath this terminal flower to some 

 4 or 5 or more lateral short leafy curvingly ascending 

 shoots each in the axil of a leaf and ending in a solitary 

 flower. The flower terminating the stolon e'xpands first, 

 the lateral ones expand in succession from below upwards 

 and we have a typical definite racemose branching. 

 Normally only one leaf of each pair in dextrorse sequence 

 gives origin to an axillary flower-branch. Sometimes in 

 vigorous stolons some of the leaves lower down upon this 

 green leafy part of the stolon may form axillary buds. 

 These are weak vegetative shoots which do not reach an 

 advanced stage of development. 



After flowering and at the end of the vegetative season 

 the whole of these branched stolons die back to the base 

 — crisply desiccating not soddenly rotting — and remain 

 attached to the rhizomatous axis around the group of green 

 shoots in the middle. These green shoots have by this time 

 altered their direction. They are now nearly in or are 

 approaching the prostrate lie, their growth in length is 

 arrested, the ultimate leaves being very small, but I do not 



