110 HOW TO GROW GOOD CLOVER. 



are grown by themselves or with grasses in shifting 

 green crops : indeed, it is by reason of clovers eking 

 out grass, or being used as pasturage, that they have 

 come to be designated " artificial grasses." 



The tribe of plants under review forms an exceed- 

 ingly natural group, which has been named Papi- 

 Uonacete, from the fancied resemblance in the arrange- 

 ment of its flowers to the form and varied colouring 

 of butterflies : by others it is designated Leguminosce 

 from the two-valved seed-pod, which by the botanist 

 is termed a legume, — most perfect examples of which 

 are seen in the fruits of our more ordinary pea 

 and bean. 



Though the flowers of the group are infinitely 

 varied in size and in colour, yet they afford most 

 permanent characters in their irregular petals, which, 

 after all, have the same parts in the variously coloured 

 and showy sweet-pea as in the most minute clover ; 

 so that, once examine the pea or bean, and the signi- 

 ficance of the name of the order depending upon the 

 flowers, will be easily understood. Again, varied as is 

 the seed-pod, yet a little examination will show that 

 its type is simple, there being no structural difference 

 between the straight legume of the pea and the 

 spirally-twisted one of the lucerne and medicks, or 

 the many-seeded smooth pod of the common broom 

 and the single-seeded wrinkled pod of the sainfoin. 



The seeds, again, may vary in colour; some, like those 

 of the scarlet-runner, are curious as affording an infinite 

 variety of self-colours for their different sorts, from pure 

 white to absolute black ; or these may be so pencilled 

 as to make a testa or seed-covering as variously 

 mottled as are the eggs of some of our birds. Yet, 

 whether rounded as in the pea, flat as in the bean, 



