PETtSONALIA 
m 
SENECJO SQUALIDUS L. 
Mr. D. H. Kent is mapping the distribution of Senecio squalidus L. 
in Britain and would be grateful for records of the species. Informatioji 
of the occurrence of the plant on the European maiidand would also be 
welcome. 
GENUS LEDUM IN BRITAIN 
Mr. B. W. Ribbons will be grateful for any information relating to 
the genus Ledum in Britain. Since the plants are so rare, specimens 
should not be collectt'd in the first instance. He will be glad especially 
to hear of the existence of any herbarium specimens. 
GENUS BHINANTEUS 
Mr. D. .1. Hambler is working on the (hums BhinnnthuR and would 
bo glad to receive seeds and specimens with details of localities. 
a ALE OB SIS SUBGENUS LADANUM 
Mr. C. C. Townsend is commencing the study of Ofilropais subgen. 
Lndanum, and would be grateful for fresh, or herbarium material of 
G. ladanum, G. anousfifolia and G. duhia forms. He would also be 
pleased to receive details, which will be treated as confidential, of any 
colonies of G. dubia known to members. 
BOLYGONUM SECT. CENTINODE DC. 
Mr. D. W. Jowett is working on the above section of Bohjgonurn in 
Britain. He would be very grateful for both material of, and informa- 
tion on B. maritirnum L., B. raii Bab., B. aviculare L. (/'. hetero- 
phyJhim. Lindm.), B. acquale Lindm., B. rurivnqum. Jord., /'. calcdtum 
Lindm., and B. litorale Link. The material may be living (including 
seed), herbarium and/or pickled for anatomical and for cytological 
study. 
NABTEECIUM OSSIFBAGTJM (L.) Huds. 
Mr. W. T. vStearn, Dept, of Botany, British Museum (Nat. Hist.),' 
Cromwell Road, London, S.W.7, is studying the British disti ibntion of 
Nartheclurri ossifraqurn (Iv.) Huds., and is anxious to receive records 
from Cornwall. If possible Grid-references should be given. 
BUGCINELLTA 
Mr. D. Lovis, of the Department of Botany, University of Leeds, 
would be grateful for seeds or plants of all sj)ecies for cytological and 
experimental studies. 
ASBLENIUM 
Mr. .1. D. Lovis of the Department of Botany, University of Leeds, 
is working on this genus, and would be grateful for spores of living 
plants of A. trichomanes from all parts of the country. He wishes also 
to determine the present distribution of A. septentrionah and A. x 
breynii, and would be glad to hear of recent records. 
