196 ONOPORDON 



ONOPOR'DON continued. 



0. macran'thum. An annual Thistle with purple 

 flower-heads and spiny leaves, glabrous or 

 smooth above, and woolly underneath. Height 

 6 ft. Barbary, 1798. 



0. taur'icum. A handsome biennial species with 

 immense woolly, spiny, silvery leaves, whitish, 

 erect and branched and purple flowers. 

 Height 6 ft. S. Europe. 



Sow the annual species 0. macranthum ^ in. 

 deep in ordinary soil outdoors in March in a sunny 

 position. 



The other species, being biennial, should be 

 sown in April, May, or June, where they are to 

 grow and flower the following year. 



OPIUM POPPY. See PAPAVER somniferum. 



OXA'LIS Wood Sorrel (from Gr. axis, acid, the taste of 

 the leaves). Nat. Ord. Geraniacece. 



This is a very large family of dwarf plants, few 

 of which are in cultivation. Those that are so are 

 principally half-hardy perennials and not robust 

 enough to stand our winter, so that they are mostly 

 treated as annuals, flowering the same year as sown. 

 The flowers, though small, are large petalled, while 

 the foliage is trefoiled. Suitable for rockeries and 

 old walls. 



0. cornicula'ta. A native plant suitable for the 

 rockery ; 6 ins. high, with small yellow flowers. 



