PEP 
: 8 . 
468 THE DICTIONARY OF GARDENING, 
Odontadenia—continued. 
shrubs, natives of tropical America, mostly Brazil and 
Guiana. Flowers yellow, showy, disposed in loose, often 
large, rarely few-flowered and scarcely branched cymes; 
calyx five-parted; corolla funnel-shaped or sub-hypo- 
crateriform. Leaves opposite, penniveined. O. speciosa, 
probably the only species in cultivation, perhaps does 
best when planted out in a prepared border in the stove, 
and the long shoots trained along the rafters. If cul- 
tivated in pots, a fairly liberal amount of root-room 
must be accorded; and thorough drainage is always 
essential. Good turfy loam, pieces of charcoal, a hand- 
ful of coarsely-crushed bones and sharp sand, make a 
compost in which the species succeed well. Insects 
must be kept in check by fumigation, or the use of 
one or other of the insecticides mentioned in this work. 
Odontadenias are propagated by cuttings of the young 
shoots, which strike readily in bottom heat. i 
speci showy). . bright yellow, shaded with orange, 
2 2 ro ap 8 aa delete scented. an large, okini 
ovate, acute, quite smooth, dark green. Trinidad, 1854. SYN. 
Dipladenia Harrisi. (B. M. 4825.) 
ODONTARRHENA. Included under Alyssum. 
ODONTOGLOSSUM (from odous, a tooth, and glossa, 
a tongue; referring to the tooth-like processes on the 
lip). Including Mesospinidium (some of the plants 
grown in gardens under the generic name of Meso- 
spinidium, belong to the genus Cochlioda). ORD. 
Orchidee. This genus comprises, according to some 
authorities, over one hundred species of handsome stove 
orchids, inhabiting the Andes of tropical America, from 
Bolivia as far as Mexico. Flowers with spreading, free 
sepals; petals nearly equal; lip with its base parallel 
with the column, and its limb deflexed and generally 
crested in various ways; column usually long, narrow 
at the base, and eared, or winged, at the summit; pollen 
masses two, with a narrow caudicle attached to an 
oval gland. Leaves in nearly all the species ensiform, 
usually sub-coriaceous in texture, linear-lanceolate or 
simply lanceolate, complicate at base, tapering to a more 
or less acute point. This genus is distinguished from 
Oncidiwm by the column being long and narrow, or, at any 
rate, not swollen, at the base, and by the base of the 
lip being always parallel with the face of the column. 
For purposes of cultivation, the Odontoglossums may 
be divided into two groups, comprising (1) all those 
species which require the treatment of an intermediate 
house, i. e., a temperature not lower than 50deg. to 
55deg. in winter, and correspondingly high in summer ; 
and (2) those which will thrive in a cool house, from 
which frost only is excluded, or, for safety, say, where the 
temperature will not fall below 40deg. Many of these 
plants, as well as other orchids, are found at very high | 
, where, at some seasons, they are visited by 
slight frosts and snow. Recently, many species of Odonto- 
glossum have been successfully cultivated out of doors 
under the shade of trees, and where the atmosphere 
about them could not become too parched. The plants 
are hung up, either in baskets or on rafts, exactly as 
when cultivated under glass, and are syringed frequently 
in dry weather; they are not injured, but, on the 
contrary, much benefited, by frequent showers of rain. 
It is probable that, as these and other orchids become 
cheaper, they will be cultivated at much less cost 
than at present, and no doubt outdoor cultivation, 
for at least a portion of the year, will be adopted 
or a great number of those from cool and temperate 
climes. Even those from warmer regions would most 
Probably be improved by open-air cultivation during our 
hot season. For the species requiring warm-house treat- 
ment, and which are distinguished in the subjoined list 
by a dagger (+), the following points must be attended 
. When making their growth, which is during the 
x they require plenty of water, a position near 
Odontoglossum—continued. 
the glass, where they would be shaded only from bright 
as, and a moist atmosphere, with plenty of fresh 
about m, care being taken that the temperature 
does n too low through the latter. During the 
winter, should be kept almost dry, and, in spring, 
quite dry till the flower spikes appear, when water should 
be applied liberally, and continued till thé summer's 
growth is again completed. s 
The species grown ın a cool house do not, as a rule, 
require a resting season similar to the above, but 
should be kept uniformly moist at the roots all the 
year round; indeed, many of them grow freely all 
through the winter. None of them like direct sunshine in 
summer, but in winter they enjoy all the sunlight possible, 
It is, therefore, a good plan to place the plants in a house 
with a northerly aspect for the summer, whilst, on the 
return of the cold, dull weather of winter, they may, 
with advantage, be removed into a house Yan aspect 
due south. In the United States, the Odontoglossums 
invariably make two growths a year, the one in summer, 
and the other in winter, the latter being favoured by the 
clear and bright light which prevails in North America in 
winter. It should be remembered that, whilst very few 
orchids—certainly no Odontoglossums—enjoy excessive 
sunlight, they are, nevertheless, much healthier and 
more floriferous when grown in a house where they can 
obtain all the light possible, short of the fierce sunlight 
of our summers. Generally, Odontoglossums require a 
moist atmosphere at all times, and, after a bright day, are 
much invigorated by a gentle dewing overhead by means 
of a syringe. A few of the species, such as O. Cer- 
vantesii, O. Londesboroughianum, O. Rossii Dawsonianum, 
&c., may be satisfactorily grown when fastened on to a 
block, formed of fern stem; but Odontoglossums succeed 
best when grown in baskets or in pots, using a mixture 
of peat (broken into lumps the size of walnuts) and 
sphagnum, with a few lumps of charcoal and a little 
sand scattered through it. Pots should be half-filled’ 
with drainage, and baskets covered at the bottom with 
a large crock, or a few pieces of charcoal. Round the 
top of the soil a little fresh sphagnum should be placed ; 
it will soon grow, and cover the whole surface with a 
fresh green, and prevent excessive evaporation in hot 
weather. To establish newly-imported Odontoglossums, 
they should be first carefully examined, and all dead 
bulbs, scales, and roots cut away; they may then be 
rinsed in warm water, and allowed to dry, before placing 
them in a little soil. The pots used should be as small 
as possible, all that is necessary being room for the base 
of the plant to stand in each with a little peat and 
sphagnum about it. Very little soil must be used, the 
pot being filled almost full of ecrocks; unless this pre- 
caution is taken, there is danger of the weakened plants 
being injured, and perhaps killed, by the water which 
would be held about them by a large body of soil. They 
should be placed in a shaded part of the house where they 
It is not wise to 
are to be grown when established. 
attempt to force the plants into growth by subjecting them 
to a high temperature, as the effect of this, although 
promising at first, is to weaken the whole plant by 
causing it to start into growth before it has recovered 
from the injuries caused by importation. All the Odonto- 
glossums are propagated by division, none having, as 
yet, been raised from seeds in this country. Mr. H. 
Veitch, in his paper on the Hybridisation of Orchids,” 
read at the Orchid Conference, on May 13th, 1885, says 
that numerous crosses between various species, both 
Mexican and New Grenadan, have been effected, and 
capsules, with apparently good seed, have been pro- 
| duced; but, with the utmost care that could be bestowed, 
no progeny has yet been raised. 
The plants which are, perhaps, best known under the 
names of O. Phalenopsis, O. Roezlii, O. vewillarium, &e., 
