398 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ May 14. 1886. 
of our readers will recognise it as an excellent likeness of the great 
orchidist and President of the Royal Horticultural Society. 
Kg. 99.—Sir Trevor Lawrence, Bart., M.P. 
ONCIDIUMS. 
Tropical America is the home of the great family of Oncidiums: hut 
though many of the 200 or more species are found in tropical latitudes, yet 
some of them ascend to such great heights in the mountains that numbers 
of the most handsome can be safely included amongst what are termed 
cool-house Orchids. Still the greater proportion of them require warm 
treatment, similar to that afforded the East Indian species. Of those which 
are found at the greatest elevation, perhaps O. Warscewiczii is the most 
remarkable, as it has been observed growing upon Oaks on the mountains 
of Costa Rica 8000 to 10,000 feet above sea level, and there the temperature 
in the coolest season falls to 40°, or even below it. The Oncidiums are of 
epiphytal habit, and they are chiefly treated as such under cultivation : but 
there are some, especially the strongest, which succeed very well under 
culture in pots, and there are few which cannot be grown in baskets. 
One peculiarity of the genus is the enormous length the inflorescence 
attains in certain species, 10, 12, and even 15 feet being reached by 
O. unguiculatum and others. Yellow, too, is the most prominent colour 
and the shades of this from the most delicate lemon to the deepest orange 
Fig. 100.—Oncidium Marshallianum. 
are very numerous. In a few purple hues are found, and perhaps one of 
the best known of these is the spotted O. cucullatum, the flowers of which 
contrast most strikingly with such types as O. concolor or O. tigrinum. 
One species—O. Papilio, the Butterfly ^Orchid—affords ’a remarkable 
example of the mimicry which renders so many Orchids interesting. The 
flower closely resembles a butterfly with expanded wings, head, antennae, 
ifcc., and so striking is its appearance that it is said a plant in flower shown 
at one of the Horticultural Society’s meetings many years ago first induced 
the Duke of Devonshire to pay attention to the Orchid family, and resulted 
in the formation of the Chatsworth collection. Several other Oncidiums 
similarly resemble insects of various kinds, and many other curious struc¬ 
tures occur in the genus, as, for instance, in O. heteranthum, from Kew, 
noted elsewhere in this report, which has two forms of flowers, one, the 
larger and most showy, perfect, and the other inconspicuous and sterile. 
As useful free-flowering plants many of the Oncidiums are of especial 
merit, such as O. ampliatum, the charming O. concolor, now flowering so 
abundantly in many gardens, O. cucullatum, O. ornithorhynchum, O. pul- 
chellum, O. Rogersii, and O. sphacelatum, in which bright shades of yellow 
predominate. To these must be added O. Marshallianum (fig. 100), a magni¬ 
ficent Orchid, one of the best in the genus. It has a large broad branched 
panicle bearing large flowers, the two lateral sepals very small and incon¬ 
spicuous, the upper being much larger and barred with brown. The petals 
are still larger, with an undulated margin, bright yellow, barred and 
blotched with brown in the centre. The lip is of great size, contracted at 
the base into a claw, which is spotted with bright red, the other portion 
being rounded, two-lobed at the apex, and of a brilliant clear yellow hue. 
This grand Orchid was first flowered by W. Marshall, Esq., of Enfield, in 
honour of whom it is named. O. nubigenum is interesting as being found 
at the highest elevation of any Orchid—namely, 14,000 feet above the sea 
level. 
The lovely O. Marshallianum, with its smaller counterpart O. ampliatum, 
were noticeable in most of the leading groups, most of the other species 
named being represented. 
DENDROBIUMS. 
A prominent position is deservedly held in Orchid collections of the 
present day by the numerous species and varieties included in the above 
Fig. 101.—Dendrobinm chrysotis. 
genus. Both in beauty and numerical strength it is probably not excelled 
by any other cultivated genu3 of Orchids, the Oncidiums and Odonto- 
glossums with the Dendrobiums forming a very large proportion of the 
total number grown in English gardens. Great diversity in the colours, 
odours, and forms of the flowers, and a general ready adaptability to 
cultural requirements, have undoubtedly been the chief means of encou¬ 
raging this popularity; but it must be further remembered that the 
majority are natives of the East Indies, occupying regions that have been 
much explored, the districts being comparatively easily accessible to the 
plant-hunter. Another point in their favour is that most of them are 
readily established after importation, and by this means few have been lost 
as compared with other Orchids. The best forms well merit all the at¬ 
tention they receive, but there are many to be found which are worthless in 
a horticultural point of view. Of the really useful forms, however, there 
are quite as many as are needed, and the chief difficulty where only col¬ 
lections of moderate extent can be grown, is selecting a few from such 
numbers of beautiful species. Few gardens containing a representative 
collection of plants will be found without some members of this genus, and 
if only one Orchid is grown it is almost sure to be the general favourite 
D. nobile. Some lovely shades of gold and purple are represented amongst 
the Dendrobes, and well grown specimens add greatly to the beauty of an 
Orchid collection. A good example of this was afforded by Mr. Prinsep’s 
fine plant of D. nobile, shown to prove the advantage of his pruning system, 
and the most exacting could not desire a more handsome specimen. In 
another section of the genus, those with the flowers in racemes, D. thyrsi- 
florum and D. densiflorum are recognised exhibition plants, many a grand 
example having been contributed to our leading shows. Of other really 
beautiful forms the following may be selected—D. Ainsworthii, D. Bensonise, 
D. bigibbum, D. Brymerianum, with a strangely fringed bright golden lip ; 
