342 ON THE TWO VALERIANS. 



of West Yorkshire, the subject is more fully discussed. Dr. Arnold 

 Lees there considers Mikanii to be a dry soil state, and nothing 

 more ; and adds — " where a dry stretch of soil slopes gradually 

 down to a ditch or stream, numerous intermediates may be 

 observed in every stage of transition, from luxuriant, succulent, 

 elder-like leaved plants by the water, to others a foot high at most, 

 with linear, deeply cut, coarsely- serrate leaflets, in the driest 

 situation." Such "intermediates " show very little approach to the 

 Mikanii now meant, which is not characterised by its coarsely- 

 serrate leaflets, or by its dwarf habit. It is, in fact, when growing 

 on a chalk-bank, as tall a plant as sambucifolia when growing in a 

 wet ditch ; or, if its height be regarded in proportion to the thick- 

 ness of its stem, it must be considered the taller plant. Dry-place 

 states of sambucifolia, which would seem to answer to the descrip- 

 tion of Dr. Lees' intermediates, are not uncommon ; such a state 

 may be seen (or might have been a couple of years ago) on the 

 wall of Kew Gardens moat, by the Thames tow-path. 



The above selection affords, I believe, a fair view of existing 

 opinions, and tbeir diversity seems a sufficient reason for giving a 

 somewhat detailed account of recent experiments. 



In the spring of 1887 I brought into the Reigate garden healthy 

 roots of the two plants— Mikanii from a hedgerow on the chalk, by 

 ± arthing Downs, near Coulsdon, and sambucifolia from a ditch near 

 Reigate. They were planted in the same bed, at a distance of 

 about two feet from each other, in the ordinary sandy soil of the 

 district, and the conditions to which they were exposed were in all 

 respects identical. The plants did not recover sufficiently to be 

 available for observations that year ; but in the spring of the 

 present year they both showed that they were in a vigorous state 

 and welhestabhshed. By May 6th they had made a good growth, 



*? irT fact of im P° rt ance noted was that while the root-leaves 



oi Ahkann spread flat on the ground, those of sambucifolia were 



erect or suberect ; and this difference was also strongly marked in 



the lower stem-leaves. When the stems were about half-grown 



the uppermost pair of leaves in Mikanii had a tendency to spread at 



once almost horizontally, even before their individual leaflets had 



oecome unfolded; while in sambucifolia they remained for some 



time not only erect, but with tbeir tips converging over the terminal 



Dua. By the 19th May Mikanii had no less than eighteen stems 



snowing good trusses of buds, most of these arising from the 



newiy-iormed stolons ; in sambucifolia none were yet visible, except 



a couple of stems from the old roots. Later on, the stolons of 



samouajolia also produced flower-stems, and that plant seemed now 



to grow more rapidly, so as almost to catch up Mikanii, which 



latter June 11th) opened its first flower exactly one week earlier 



man the Ooher But I think that there is probably more difference 



in tne time of flowering tban is, in this instance, represented by 



tne opening of the first blossom, for Mikanii was seeding pretty well 



wnen sambucifolia was still in good flower. Koch gives the 



fiowering-time as follows:-- V. omcmalis," May, June; V. sum- 



buafoUa, June to August 



