bXlllBlTlON MEETlNOj 1900 
dry conditions and was very much less luxuriant. It was 
destroyed by further dumping of rubbish. 
J. E. Louslev. 
AIRA AIUETICtJLMIS DUMORT. 
This plant, variously classed as a species, subspecies or variety 
of A. caryophyllea L. in the past, has been shown to possess 
twice as many chromosomes as the latter. When typical, it is 
easily recognisable by its much more robust growth in dense 
tufts, contracted panicle and smaller, more swollen glumes. It 
also differs in its relatively very broad, dense, glaucous winter- 
ing tufts, and in the numerous new flowering culms, which are 
developed from the base of the culms which have passed out of 
flower. This after-flowering may continue through the whole 
summer and autumn and perhaps even winter, so that polyploidy 
has been accompanied by an extension in the duration of life. 
The species has a well defined distribution, being a native of 
North Africa and South-west Europe, north to England and 
Holland. Dumortier found an ecological difference in Belgium ; 
A. mvlticwlmis frequents wood borders there, whereas A. 
caryophyllea keeps to bare, sandy places. 
In England it is known from Surrey and Buckinghamshire, 
and it also grows on at least two of the Channel Islands. There 
are more doubtful records from Devon and other southern 
counties. More material is needed before its English distribu- 
tion can be ascertained in detail. D. E. Allen. 
VEGETATIVE REPRODUCTION IN OPHIOGLOSSUM VULGATUM L. 
The two sheets exhibited were of three plants of the Adder’s- 
tongue fern collected at Mochras, Merioneth, during the Dol- 
gelley excursion in July 1948, and grown at Kew for two years. 
It is well known that this fern reproduces vegetatively by means 
of adventitious buds on its roots, but it is very difficult, owing 
to the brittle nature of these roots, to obtain specimens demon- 
strating this fact. During the two years of cultivation at Kew, 
the three original plants had produced, or were in the process 
of producing, eleven new plants, at distances of from three to 
nine inches from their rootstocks. That the original plants 
were also formed in this way is demonstrated by the fact that 
at the lower extremity of each vertical rootstock is a continuous 
horizontal root. An examination of specimens in the Kew her- 
barium indicates that most of these originated in this manner. 
It seems probable, therefore, that this species relies mainly on 
these root buds as a means of reproduction, the conditions neces- 
sary for the germination of spores and development of prothalli 
possibly occurring only infrequently in many of its habitats, 
and observations in the field tend to support this, the plants 
usually being found in more or less compact colonies. 
Peter Taylor. 
