STELLARIA NEMORUM L. SUBSPECIES GLOCHIDISPERMA Murbeck 



IN BRITAIN 



By p. S. Green 



Royal Botanic Garden, Edinburgh 



Introduction 



In June 1953 a short paper was published by A. Lawalree (1953) in which attention 

 was drawn to the existence in Belgium of subspecies glochidisperma of Stellaria nemorum. 

 As this subspecies seems quite distinct and had been overlooked for some time in the 

 Belgian flora, I decided to look at the material in the British Herbarium at the Royal 

 Botanic Garden, Edinburgh, and there discovered a single specimen (Plate la). It had 

 been collected at Llandogo in Monmouthshire more than a century ago and the label 

 reads : " Ex Herb. F. Farre, Llandogo, Monmouthshire, at the falls, 32.6.29." 



Distribution 



In order to confirm this record and see whether further specimens and records from 

 Britain exist, material was studied from the following herbaria, to whose authorities 

 grateful acknowledgment is made : Aberdeen University, Birmingham University, 

 British Museum (Natural History), Cambridge University, National Museum of Wales 

 and Royal Botanic Gardens, Kew. In all, collections have been discovered from four 

 counties : Monmouthshire, Cardiganshire, Montgomeryshire and Merionethshire. The 

 detailed localities, together with a formal description, are given at the end of this paper. 



Very recently Lawalree (1954a) has recorded the occurrence of subsp. glochidisperma 

 in France and Spain, and at the conference of the Botanical Society of the British Isles, 

 held on April 9th and 10th, 1954, Dr. Ch. H. Andreas of Groningen read a short paper 

 in which she discussed its occurrence and ecology in Holland. These records have con- 

 siderably extended the known range of the subspecies on the continent. It was originally 

 described from Yugoslavia (from that part formerly known as Herzegovina) and is a 

 central European subspecies, reaching in the north as far as southern Sweden and eastern 

 Denmark, in the west to Wales, France and central Spain and in the south to Corsica and 

 Italy (the Apennines). Its eastern limit is uncertain but it is probably the plant named from 

 Russia as var. suhehracteolata Fenzl (Ledebour 1842). A map showing its distribution in 

 Scandinavia is given by Hulten (1950). 



Description 



Stellaria nemorum subsp. glochidisperma is most easily distinguished with certainty 

 from subsp. nemorum by two characters : one of the inflorescence and the other of the seed. 



In subsp. nemorum the bracts of the inflorescence decrease gradually in size at each 

 dichotomy of the cyme (Plate lib), whilst in subsp. glochidisperma their size decreases 

 abruptly after the first pair. The second pair is rarely more than a quarter of the length 

 of the first, and the third is characteristically scale-like (Plate Ila). In those specimens 

 of subsp. glochidisperma investigated, the length of the second bract ranges from 10-27% 

 of that of the first (with one robust specimen up to 50%, but even then with extremely 

 small third bracts), and in subsp. nemorum from 30-85%. It is important not to mistake 

 the small flowering branches which occur occasionally in the axils of the upper leaves for 

 the first branches of the inflorescence (Plate Ila). The inflorescence proper always has a 

 flower arising between the two dichotomous branches. 



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