4 Buried Weed Seeds 



seeds which must have been buried for -45 years, as at the time the field 

 was cleared it was covered with these plants. When some new trees were 

 planted 14 years later the same species reappeared, after burial for 59 

 years. 



Peteri ^^qqJ^ samples of soil in forests of known anterior conditions at 

 depths of 8, 16, and 25 centimetres. He found that the number of seeds 

 which germinated diminished with the depth, and that at 25 centimetres 

 the seeds were very scarce. Old forests only gave wood species, recent 

 forests which had originally been prairie and field furnished some seeds 

 characteristic of these situations. 



The most abundant species were: 



(1) Juncus biifonius, J. conglomeralus, Sngina procumbens, Hyperi- 

 cum perforatum, Ranunculus repens, Plantago major, Gnaphalium 

 uliginosum. 



(2) Chenopodium polgspermum, Ruhus Idaeus, Potenfilla Tormen- 

 tilla, Linaria Elatine, Centunculus minimus. 



Peter concluded that many of the seeds could retain their vitality for 

 half a century. 



Passerini- carried on germination experiments in pots with seeds of 

 Orobancke crenata for 14 years, and found that the seeds lost practically 

 all power of germination after lying in the soil for eight years. 



Dorph-Petersen^ carried out germination experiments with weed seeds 

 in order to find out how long they retained their power of germination 

 when buried in soil. Thlaspi arvense, Sinapis arvensis. Geranium molle, 

 and MaJva rulguris often lay dormant for 6-12 years before germinating. 

 It appeared that the rapidity of germination was affected by the length 

 of time seeds were kept before planting, and also that ripe seeds had a 

 higher germinating capacity and retained it longer than unripe seeds. 



Pots containing 100 seeds of each of Plantago lanceolata and Sinapis 

 arvensis were placed 12 ins. below the surface of ground in 1S99, and each 

 year after one pot was dug up and the seeds were allowed to germinate. 



With Plantago lanceolata two- thirds of the seeds were dead by 1900 



but 8 % still retained their germinating capacity after 10 years. In dry 



torage a similar lot of seeds kept their viability well for a few years, 



but all were dead in 10 years. With Sinapis arvensis the germinating 



' Quoted by Becquerel, loc. cit. 



' "Duration of vitality of seeds of Orobanchc crcnuhi," Alii R. Arrad. Ecoii. Agr. Geogr. 

 Firenze, Series 7, 1910, 5, No. 1, pp. 1-7. 



' Jahrest>.derVereiiiigu7ig fur ayigewandte Botanik, 1910. vSumraarised in JoMrn. Boarci 

 Agric. 1911, pp. 599-600. 



