280 



JOHN ERNST WEAVER 



numerous large yellow flowers 2.5-3 inches in diameter make 

 these societies very conspicuous. 



The fleshy tap root sometimes measures 9 inches in circum- 

 ference and may reach a depth of 6 feet and 5 inches. It usually 

 has several strong laterals which come off from 8 inches to 3 feet 

 in depth, and may run out in a somewhat horizontal direction 



Fig. 13. Fig. 14. 



Fig. 13. Geranium viscosissimum. The crown is partly decayed. The roots 

 are so brittle that they are removed from the soil with extreme difficulty. Five 

 hours were spent in securing the above specimen. 



Fig. 14. Two roots of the black sunfl6wer, Wyethia amplexicaulis. Note the 

 numerous short laterals. 



for 3 or 4 feet from the main root. Sometimes, however, only a 

 single lateral occurs. Often at a depth of 1-3 feet the whole tap 

 breaks up into 2-5 nearly equal parts which pursue a downward 

 course, or later extend out as laterals. Primary laterals are not 

 much branched. The whole root from crown to near the tip 

 is covered with scattered small laterals usually not over 2 milli- 



