OPUNTIA, Cactaceae. Prickly-pear. Procumbent cacti with 
brightly colored flowers and pear-shaped usually edible fruits 
[5E]. 
O. fragilis. B. C. and Wis. to Tex. 
O. humifusa ( O . compressa ). Mass, to Ala. and Mo. 
O. phaeacantha. Ariz. and Tex. 
O. polyacantha. N. D. to Alb. and Tex. 
O. rhodantha. Colo. 
ORIXA, Rutaceae. Dense aromatic shrub with glossy leaves 
[6E], 
O. japonica. Japan. 
OSMANTHUS, Oleaceae. Evergreen shrub with holly-like 
leaves and small fragrant flowers. Unlike the hollies (Ilex), this 
plant has opposite leaves [8E]. 
O. ilicifolius. Japan. 
OSMAREA, Oleaceae. A bigeneric hybrid shrub with ever¬ 
green foliage. It is not reliably hardy [8E]. 
O. Burkwoodii (Phillyrea decora x Siphonosmanthus Delavayi). 
OSMARONIA, Rosaceae. A large shrub with grayish-green 
foliage; not sufficiently hardy to warrant general planting in 
our locality [nursery]. 
O. cerasiformis. Osoberry; B. C. to Calif. 
OSTRYA, Betulaceae. Hop-hornbeam. Medium-sized trees 
with hanging fruits that resemble hops [6E]. 
O. carpinifolia. European H.; S. Eu., Asia Minor. 
O. virginiana. American H.; Ont. to Fla. and Tex. 
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