OOIVIPASS OP ECONOMIC PLANTS. 129 



Buttercup family (EanunculaceaB), native of Britain, In its 

 wild state the flowers are generally blue, but from its being 

 long a favourite garden plant, many varieties have been raised 

 of different colours^ and some with double flowers. It derives 

 its name Columbine from the curved petals being compared to 

 birds, the sepals forming the wings. 



Colza Oil. {See Eape.) 



Comfrey (Symjphytum officinale), a strong-growing peren- 

 nial of the Borage family (Boraginace^), native of Britain. It 

 has long had its virtues extolled, but, Kke those of Borage, 

 they are imaginary. The young sprouts are sometimes blanched^ 

 and used as asparagus. S. peregi^inum, generally described as 

 S. asperrimum, grows taller, and, with its pretty blue pendulous 

 flowers, is a more showy garden plant than the preceding; 

 native of the Caucasus ; introduced about the beginning of the 

 present century. Although a rough-leaved plant, it is neverthe- 

 less relished by cattle. Some years ago it came into notice as 

 a fodder plant, and trials of it show that, if properly cultivated, 

 an acre will yield as much as 40 to 50 tons of green food. It is 

 found to be rich ia gum mucilage and sugar. 



Compass or Polar Plant, a name given in the United States 

 to Silphium laciniatum, a strong-growing perennial of the Com- 

 posite family (Compositss). It grows to a height of 4 to 6 

 feet, the upper part branched, each branch terminated by a head 

 of yellow florets. Its leaves are of an ovate form, but winged 

 and jagged, of which Dr. Asa Gray says — " On the wide open 

 prairies the leaves are said to present their faces uniformly north 

 and south. From this circumstance it is called the Compass 

 plant." There are several other statements to the same effect, 

 but taking them altogether, there is still a degree of uncertainty 

 regarding the direction of the leaves always pointing north and 

 south. It is also known by the name of Eosin, or Turpentine 

 Plant, consequent on the resinous substance which issues from 

 its stem. It has been noticed by travellers in the prairies that 

 mosses and lichens grow most abundant on the north side of the 

 trees, which circumstance serves as a guide to travellers. 



