558 
Oak Fungi—continued. 
The remedy lies in cutting out the diseased portions and 
coating the parts with a tar preservative. So far this 
fungus has not been found in England. A near relative, 
however, S. hirsutum, is very common here, and is 
responsible for a rotten condition. Being alike a 
saprophyte and a parasite, it is especially objectionable, 
in the latter case gaining access throngh a wound. 
The sporophores are variable as to shape, and very 
tongh, with wavy edges, while the upper surface is 
hirsute. All dead wood should. be removed. The 
diseased portions should be ent out, then treated to a 
solution of bichloride of mereury (a virulent poison, - 
and exceedingly corrosive), and coated with tar. Oak- 
root Fangus (Rosellinea quercina) is peciliar to seedling 
Oaks, and therefore of moment to the forester and the 
nurseryman. Hartig, who has devoted some considerable 
study to this fungus, which is very prevalent in some 
parts of the Continent, says that it spreads very rapidly 
during wet summers. Its presence is readily indicated 
by the leaf condition, which is unhealthy, and by the 
presencee of the strands of white or (later) brown 
mycelinm attached to the roots and trayersing the soil 
in search of other bost-plants, and by the black 
selerotia. Conidia are produced upon the mycelium, and 
by these the fungus is developed in summer; while 
perithecia, from which are evolved ascospores, are also 
present, and by these the fungus is reproduced in the 
spring of the next season. All infested seedlings should 
be uprooted and burned, and the spread of the disease 
should be prevented by the digging of trenches. 
OAK-LEAF GERANIUM. ‘See 
quercifolium. 
OAK-LEAF ROLLER MOTH (Tortrix viridana). 
This Common Moth will be found described under 
Tortrix (Vol. IV.), and also under Oak (Vol. II.). 
The caterpillars are very familiar, as they may be found 
by thousands in certain seasons suspended in mid-air, 
having let themselves down from their spun-together 
Pelargonium 
cylindrical retreat. They vary considerably as _ to 
eolour. At first they are greyish, but as they get 
full-fed they assume a greenish colour. These pests 
usually undergo the final change in the tubes which 
they have ingeniously constructed; but circumstances 
frequently arise which practically compel them to take 
shelter in the bark of the Oaks on whose foliage they 
have fed. Then they lightly cover themselves with a 
thread-like substance which they spin. 
So numerous are these foes in our woods and planta- 
tions that the trees are often quite defoliated. So 
far, no really practical remedies have been devised for 
dealing with the insects; while the fact that the Oak 
produces a second crop of sound leaves tends to show 
that the trees are not seriously injured. 
OAK-ROOT FUNGUS. ‘See Oak Fungi. 
OAK, SHE. See Casuarina stricta. 
OBERONIA. To the species described on p. 465. 
Vol. 11., the following should be added : 
O. acaulis (of B. M.). The correct name is O. ensiformis. 
o. Myosurus (Myosurus), jl. buff, minute, in a dense spike 
less than 4in. long; scape very short and stout. 7. radical, 
3in. to 4in. long, 4in. in diameter, terete, curved. Nepal, 
Birma, &c., 1896. 
0. rufilabris (red-lipped). jl. yellow, ultimately changing to 
light red, with a reddish-brown lip, minute, in dense whorls ; 
scape and raceme together lin. to 2in. long, the latter nodding. 
Z, lin. to 1jin. long, thin, narrow-oblong. Birma, 1881. 
OBLONG WEEVIL (Phyllobius oblongus). See 
Phyllobius, Vol. III. 
OCA. The native name of the edible tubers of Ovalis 
tuberosa in Bolivia, where they are used like Potatoes. 
OCHROPTERIS. 0. pallens is a beantiful and 
very rare Fern, having the general habit and texture of 
an ample-fronded and much-divided Davallia. The plant 
requires an abundance of heat and moisture all the year 
round, and a compost of three parts peat, two parts sand, 
and one part loam. Like the majority of Ferns from 
the same habitat, it is averse to strong light. We are 
not aware that this interesting plant has ever been 
raised from spores either in this or in any other country 
in Enrope. 
THE DICTIONARY OF GARDENING, 
OCIMUM. To the species described on p. 467, 
Vol. II., the following should be added : 
0. comosum (tufted). /. blackish-purple. 2. 
Habitat not recorded, 1889. An annual, in 
0. Basilicum, of which it is probably a variety. 
O. gratissimum (very grateful). jl. pale yellow, very small; 
racemes erect, slender, the whorls rather closely set. July and 
August. /. glabrescent, ovate, acute, 2in. to 4in. long, crenate 
or coarsely toothed; petioles lin. to 2in. long. h. 4ft. to 6ft. 
India, &c., 1751. Shrub. 
O. minimum is a form of 0. Basiliewm. 
O. suave (soft). This mainly differs from 0. gratissimum in 
having the leaves densely and softly tomentose on both sur- 
faces. Africa, 1816. 
OCOTEA includes Strychnodaphne. 
OCREA. The correct spelling of Ochrea. 
bright green, 
the way of 
OCTA-, OCTO-. Hight; e.g., Octomerous, eight- 
parted. 
OCTADESMIA. 0. serratifolia is the correct name 
of the plant described on p. 467, Vol. II., as O. montana. 
OCTOMERIA. To the species described on p. 467, 
Vol. II., the following should be added: 
O. cochlearis (snailshell-like). /. bent sideways; sepals and 
petals whitish-ochre, tailed; lip trifid, hairy, light sulphur, 
with a purple blotch on the disk. JZ. strong, cochleate, 
glaucous, purple beneath, with numerous transverse furrows. 
3razil, 1881, 
O. diaphana (diaphanous). . white, transparent, scentless, 
solitary; sepals and petals very acute; lip three-toothed, the 
margins slightly crisped. 7. ovate, convex, acute, Upper part 
of the stem invested with large sheaths. Brazil. A small but 
pretty species. 
O. supraglauca (glaucous above). jl. Zin. long; sepals and 
petals pale glassy-green, faintly tinted purplish outside, lanceo- 
late, acuminate; lip one-fourth as long as_the sepals and 
petals, obtuse, yellowish, with a large, lurid-purple blotch ; 
peduncles bearing two or three flowers. 7, elliptic, fleshy, 
whitish-green above, beneath dark green, obscurely tessellated 
with dark purple, and minutely furrowed. 4k. about 2in. 
Brazil, 1887. Plant tufted. 
Several other species are grown in botanical establishments, 
but they are of little or no horticultural value. 
OCTOMERIA (of D. Don). 
(which see). 
ODONATA. See Dragonflies. 
ODONOPTERA BIDENTATA. The caterpillars 
of this common Moth are frequently met with in gardens, 
feeding upon a variety of trees and shrubs—Hazel, Birch, 
Ivy, chiefly. To the last-named they are often very 
destructive. The Moth is over 1din. in wing expanse, and 
may be found during May and June. The caterpillars are 
feeding during July, August, and September; they are 
not readily found, however. In colour they are a light 
grey, or brown, with darker markings upon the back: 
sometimes, too, they are blackish, with pale greenish 
markings. When fnll-fed they pupate just below the 
surface of the soil, or beneath any rubbish likely to afford 
the necessary shelter, the perfect insects appearing the 
following season. When Ivy is badly attacked the food 
plant should be poisoned with Paris Green, 20z. to the 
gallon of water. 
ODONTOCARPA. 
(which see). 
ODONTOGLOSSUM. No Orchids haye been so 
extensively imported as the O. crispwm section of Odonto- 
glossams. In many of these importations startling 
novelties have appeared; and several supposed natural 
hybrids between the different species which are known 
to grow together have also been introduced, and in many 
instances they have proved desirable additions to these 
charming plants. The ‘‘garden hybrids” have been 
useful, inasmuch as they have determined the identity 
and origin of some of the natural hybrids. In other 
instances, but especially in those hybrids which have 
been procured through the influence of O. Harryana as 
one of the parents, distinct and desirable additions have 
been made. The raising of Odontoglossums from seed 
is now being extensively practised, and frequent additions 
may be expected in the near future. 
One of the principal details in the culture of the cool 
section of Odontoglossums in the past was the supposed 
A synonym of Eria 
A synonym of Valerianella 
r necessity for haying a house with a northern aspect, or 
