AGRICULTUR.\L SEEDS 1609 



samples of seeds of cultivated plants and a complete botanical analy- 

 sis of the weed seeds in order to be certain which of the latter may be 

 considered as characteristic of a given district. 



The investigations here described were made on seed samples from 

 the maritime region of eastern Siberia, and were supplied to the seed 

 control station by the Department of Agriculture. The samples were 

 taken during the winter of 1910-1911, and the}' all belonged to the 1910 

 harvest. They were representative of the condition in which the farmers 

 send the grain to the market or mill; this material obtained direct from the 

 the producers was exceedingly valuable ^or the botanical analysis of weed 

 seeds. 



The district was divided into seven zones according to the methods 

 of cultivation adopted, and the results were group.ed to correspond. This 

 division, however, has no direct bearing on the problem in hand, and it 

 has onh' been used in drawing up the tables for the benefit of those who 

 desire to study the farm seeds used in the district. 



Seed samples of cereals (wheat, r3'e, oats, barle}-), buckwheat and 

 flax were examined. It appears that Commelina communis L. famil}'' 

 Commelinaceae Reich, is widely distributed in the district. In view of 

 the fact that this plant is completely absent in samples of cereals deriv- 

 ed from western Siberia, which have been analj^sed at this Station, it is 

 considered that the presence of seeds of Commelina conimiinis L. may, 

 be taken as an indication that the samples come from eastern Siberia, 

 probably from the maritime region. 



In 1913 and 1915 Commelina communis seeds from the 1910 harvest 

 were 30wn in the Imperial Botanic Garden of Peter the Great, at Petro- 

 grad, and the}^ grew well in every case. This shows that the seeds retain 

 their germinating capaciy for a long time (it was still about 55 per cent at 

 the end of six 5'ears and that the plant will grow in the west. 



Commelina communis seeds are earth colour and resemble bits of 

 earth in shape. The dimensions are : length, 2 to 4 m.m, breadth 1.5 to 

 2.9 m.m : on the average, the length is 2.7 m.m., breadth 2.3 mm. The 

 weight of I 000 seeds averages 7.9 gms. and the weight of a single seed 

 varies from 0.005 to o.oii gm. 



In Manchuria the colouring matter of the petals of Commelina communis 

 is used to dye cotton thread blue. 



Among the harmful weed seeds found in the samples analysed, at- 

 tention was attracted to those of Agrostemma Githago, which were much 

 larger and heavier than the seeds of the same plant derived from certaiu 

 localities of Russia in Europe (i). In this connection the following data 

 maj' be given. 



Avena jatua was also found. This has hithe^o been regarded as 

 unknown in the district under consideration but these experiments indi- 

 cate that it must have been imported with cereal seeds ; it is now well 

 established even in the extreme East. 



(i) See R. September 1916. No. 968. (Ed.). 



