LATE GLACIAL PLANTS OF THE LEA VALLEY 197 



form of L. usitatissimum, till now unknown. The cultivated flax 

 is, however, essentially a temperate species, and it is not easy to 

 imagine that the flax of ancient cultivation in Egypt, found also 

 in the Swiss lake-dwellings, can be descended from a plant essen- 

 tially Arctic. Possibly the common flax of our latitudes may bo a 

 hybrid between this Arctic plant and a southern form, for there is 

 more than one variety of flax in cultivation, though none seems 

 quite to match the fossil here described. 



In the circumstances, it is difficult to decide what name should 

 be given to the Lea Valley Linum, for, so far as the seed goes, the 

 differences are not sufficient to make it more than a variety of the 

 common flax. But, even if it be treated as an ancestor, or one of 

 the ancestors, of common flax, the question of nomenclature still 

 remains. There seems as yet to be no definite rule which fixes the 

 name to be applied to a w^ild form of an animal or plant origin- 

 ally described from cultivated specimens, and to which was given 

 such a name as usitatissimum, implying domestication. I can only 

 suggest the use of Linum i:)rceGursor in this case — for, although 

 the plant may be the ancestor of our own flax, it is probably only 

 one of the ancestors. 



Dr. O. Stapf, the Keeper of the Kew Herbarium, having been 

 consulted on this point, strongly advises the use of a new specific 

 name for the fossils here described. He points out that the seed 

 is markedly different in shape from that of L. usitatissimum, and 

 that, in view of the Arctic climate indicated by the other plants, 

 the relationship of the fossil to the living form is very prob- 

 lematic. He also points out that, in the case of the wild rice, 

 we have a precedent for giving a new specific name to a plant which 

 is probably the ancestor of a form long in cultivation. 



Linum precursor, sp. nov. 



A L. usitatissimo, seminibus angustioribus magisque oblongis 

 recedit. 



Vicia sylvatica. This north-country vetch has not previously 

 been recorded in the fossil state. Valves of the pod are not 

 uncommon at Angel Eoad and Temple Mills ; they are somewhat 

 smaller than my recent specimens, but agree in other respects. 



Armeria arctica. The fruiting calices of this Arctic- American 

 and Greenland plant are common in the Lea Valley, but were only 

 recognised as European fossils in 1914 by Dr. C. A. Weber." They 

 occur in various deposits in Britain ; the plant is, however, no 

 longer living in Europe or Asia, and I gave " Sibera " as a record 

 through a misapprehension of Weber's account.! 



Samhucus nigra. A single seed of the elder has been sent to 

 me from Angel Road. It is in a different state of preservation 

 from the other fossils, and may possibly be washed out of some 

 more ancient deposit. From Bonder's End I have a single much- 

 worn nut of Carpinus Betulus. Neither the elder nor the horn- 



* "Die Mammutflora von Borna," Abh. Nat. Ver. Bremen, vol. xxiii, pt. 1. 

 t C. Keid. '^Armeria arctica WaUr. Fossil in Britain," Journ. Bot. vol. Hi 

 (1914), p. 215. 



