ORNITHOGALUM OXYLOBIUM. 287 



Ornithogalum (Star of Bethlehem). Liliaccz. 



Seeds. Commonly by bulbels, and by division. 

 Orobus (Bitter Vetch). Leguminoscz. 



Readily propagated by seeds, or by dividing the tufts. 

 Orontium. Aroidece. 



Commonly increased by division, but seeds may be used. 

 Orpine. See Sedum. 

 Osage Orange. See Maclura. 

 Osier. See Salix and Cornus. 

 Osmanthus (Japan Holly). Oleacecz. 



Propagated by cuttings under glass, or by grafting on 

 osmanthus stock, or on privet. 



Osmunda (Flowering Fern). Filices. 



Mostly by division ; sometimes by spores. See Ferns. 

 Ostrowskia (Giant Bell wort). Campanulacecz. 



Propagated in the same manner as the perennial cam- 

 panulas, which see. 



Ostrya (Hop Hornbeam, Ironwood). Cupuliferce. 



Best grown from seeds. Also increased by layering ; 

 or it can be grafted. Th<3t European species is often 

 grafted upon the hornbeam (carpinus). 



Othonopsis, Othonna (Ragwort). Composite. 



Very easily propagated by seeds and cuttings. The 

 leaves also take root. 



Ouvirandra (Lattice-leaf). Naiadacece. 



The plants are divided ; or seeds are used when they 

 can be obtained. 



Oxalis. Geraniacetz. 



Seeds, divisions and cuttings. The tuberiferous species 

 are increased by the small tubers upon the roots. 



Oxydendrum (Sorrel-tree). Eriacacecz. 



Increased by seeds, which must be handled carefully in 

 light soil. Also by layers, which, however, often root 

 with difficulty. 



Oxylobium (Callistachys). Leguminosce. 



Cuttings of firm wood, in spring, under glass. 



