VIII. SEEDLINGS OF CERTAIN WOODY PLANTS. 



FRANCIS RAMALEY. 



The following observations on seedlings of woody plants 

 were made at the University of Minnesota, during the years 1896, 

 1897 and 1898. The plants were grown from seed either col- 

 lected by the writer, or obtained from reliable dealers. 



Most of the species studied have not hitherto been investi- 

 gated. The author has, however, re-examined some plants de- 

 scribed by former investigators, especially in cases where the 

 printed descriptions were incomplete or without illustrations. 



The measurements given are in all cases based on a consider- 

 able number of plants examined. It has been found that the 

 exact lower limit of the hypocotyl is not always 'readily deter- 

 mined, although, generally it is enough larger in diameter than 

 the root to be exactly located. It has seemed best in giving the 

 length of the hypocotyl to measure its full extent rather than 

 simply that part above the ground. 



An attempt has been made to note, as far as possible, whether 

 the seed coat is carried up or remains underground and also 

 how much the cotyledons increase in size after appearing above 

 the ground. These points have not generally been noted by 

 students of seedlings. 



In most cases the length of time required for germination of 

 the seeds is given. The figures are for the first seedlings. 

 Oftentimes plants will appear every few days for over a month 

 after the first have come up. Unless otherwise stated it is to be 

 understood that the seeds were planted in the following spring 

 after ripening. The plants studied will be considered in the 

 order of Engler and Prantl. 



SALICACE.E. 

 Populus deltoides MARSH. 



The seed of the " cottonwood " ripens in June and should be 

 planted at once. The young plants appear above ground in a 

 week or sooner. 



