ENCYCLOPHDIA OF GARDENING. 
varieties illicifolius (small-leaved), Jatifolius (broad-leaved), latifolius variegatua 
(variegated), purpureus (purple-leaved),and myrtifolius (myrtle-leaved); fragrans 
(Syn. Olea fragrans), white, fragrant, June to Aug., 6 to 10 ft., Ohina and Japan. 
Osmunda (Royal Fern; af ect Fern).—Ord. Filices. Green- 
house and hardy evergreen & deciduous ferns. Fronds, feather-shaped, 
plain or crested ; fertile portions contracted. 
CULTURE OF GREENHOUSE SPECIES: Compost, equal parts 
turfy loam and peat, little sand. Position, pots or beds in moist shady 
part of greenhouse or fernery. Pot or plant, March or April. Water 
copiously April to Oct., moderately afterwards. Temp., 55° to 65° 
April to Sept., 45° to 55° Sept. to April. 
CULTURE OF HARDY SPECIES: Soil, one part each loam, leaf 
mould & sand, two parts peat. Position, bases of sheltered moist 
rockeries or margins of ponds in shade or partial shade. Plant, April. 
Top-dress annually in April with compost of peat, leaf-mould & loam. 
Remove dead fronds in March. Water plants growing otherwise than 
on the margins of ponds copiously in dry weather. Propagate by spores 
sown on surface of sandy peat & leaf-mould in well-drained pans, 
covered with sheet of glass or hand-light in shady part of cool green- 
house at any time; offsets from established plants in April. 
GREENHOUSE SPECIES: O. bipinnata, 2 ft., Hong Kong; javanicum, 2 to 4 ft., 
ava. 
HARDY SPECIES: O. cinnamomea, 2 to 4 ft., N. America, West Indies, eto.; 
Claytoniana, 2 to 3 ft., N, America and Himalayas; regalis (Royal Fern), 3 to 
6 ft., Britain, etc., and its varieties corymbifera, cristata, palustris, an pur- 
purascens. 
Oso-berry-tree (Nuttallia cerasiformis)—See Nuttallia. 
Ostrich Fern (Onoclea germanica).—See Onoclea, 
Ostrya (Hop Hornbeam).—Ord, Cupulifere. Hardy deciduous 
trees. Flowers, greenish white, hop-like; May. Tirst introduced 1622. 
CULTURE: Soil, ordinary moist. Position, by the side of streams, 
lakes, or in shrubberies in damp situations. Plant, Oct. to Feb. Pro- 
pagate by seeds placed in a heap outdoors till spring, then sown in 
sandy soil outdoors; by cuttings inserted outdoors in autumn; by 
layering in summer; by grafting on the Hornbeam (Carpinus betulus) 
in March. 
SPECIES CULTIVATED: O. carpinifolia (Hop Hornbeam), 20 ft., 8. Europe; 
virginica (Ironwood), 20 ft., N. America. 
Oswego Tea-plant (Monarda didyma).—_See Monarda. 
Othonna (African Rag-wort).—Ord. Composite. Greenhouse 
trailing herbs. First introduced 1752. 
CULTURE: Compost two parts sandy loam, one part leaf-mould & 
one part sand. Position, small well-drained pots or baskets suspended 
from roof. Pot, March or April. Water steely April to Oct., mode- 
rately afterwards. Apply stimulants to healthy plants occasionally 
during summer. Full exposure to light & sun essential. Propagate 
by cuttings of shoots inserted in sandy soil in cool greenhouse or frame 
in summer; division of plants in April. _ en 
SPECIES CULTIVATED: 0. crassifolia, yellow, summer, trailing, 9. Africa. 
Ourisia.—Ord. Scrophulariacee. Hardy perennial creeping herbs. 
First introduced 1862. a2 ; 
CULTURE: Soil, moist loamy. Position, partially shaded rockery, 
with its roots placed close to a lump of soft porous stone. Plant, March 
or April. Water freely in dry weather. Must not be exposed to sun- 
shine. Propagate by division of roots in March or April. 
SPECIES ou TIVATED: O. cespitosa, white, summer, 6 in., New Zealand; 
coccinea, scarlet, summer, 8 in., Chiloe oe crimson, summer, 8 in. 
