204 August, 



NOTES ON ARUM MACUI.A.TUM. 



BY R. A PHII,I,IPS. 



For some time past I have been interested in the distribution 

 of the maculate-leaved form of the Common Arum, and 

 having many opportunities, in the course of long drives in 

 various parts of Southern Ireland during the early spring 

 months, of observing the relative frequency of the spotted and 

 immaculate forms of this plant, I have taken some notes of 

 same. Mr. Colgan's paper in the Irish Nahcralist of last 

 March led me to look into the matter more closely, and the 

 subsequent interest shown in the subject by other Irish 

 botanists has induced me to publish the results of my obser- 

 vations. 



During February, March, and April, when other vegetation 

 is scarce, the Arum leaves are at their best and most con- 

 spicuous ; after that they begin to decay and become quickly 

 hidden by the rushing tide of earl}^ summer foliage. . The first 

 thing that strikes one in these earl}^ months is the great 

 abundance of the species. For miles along shady roadsides in 

 all directions it is constantly seen, but a botanist going over 

 the same ground during the summer months would probably 

 put it down as a scarce plant. 



Although usually considered a denizen of woods, in which 

 habitat it attains its greatest luxuriance, it seems equally at 

 home along roadsides, the corners and edges of pasture fields, 

 and among the fissures in the rocks of the limestone pave- 

 ments of Western Ireland. 



The spotted form, though undoubtedly scarce, is wideh^ 

 spread, and I have seen individuals in nearly every district in 

 which I have looked for it, the exceptions being near the sea 

 and among the limestone crags. 



It usually occurs in solitary clumps of one, two, three, or 

 four plants, always accompanied by far larger quantities of the 

 unspotted form. I have seen it in exposed spots on roadsides, 

 in which situation the spotted plants seem weaker and inclined 

 to " go off" earlier than the green ones ; in thin copses, and 

 in densely shaded places in woods. In no case did I notice 



