CH. XIV] BURRS. 187 



with a characteristic rotation, and which are not seeds, 

 nor ovaries as in the ash, but half-fruits. 



Fm. 88. 



RlPE FRUIT OF THE SYCAMORE, 



splitting into two winged compartments. 

 From Le Maout and Decaisne. 



II. Burrs. 



A burr is a fruit (or in some rare instances a seed) 

 armed with hooks, by which it adheres to the hair of 

 animals. Among English plants the most familiar in- 

 stances are the common "cleavers," i.e. the hook-bearing 

 fruit of a Galium, the large burrs of Arctium lappa, the 

 Burdock, and the hooked fruits of Herb Bennet (Geum 

 urbanum) which is included in the Practical Work, No. 

 xiv. A country walk is enough to convince anyone that 

 two of these, cleavers and the fruit of Herb Bennet, are 

 effective burrs. 



Burrs are so common in wool that they require special 



