AN ENCYCLOPZDIA OF HORTICULTURE. 
491 
Oncidium—continued. 
O. uniflorum (one-flowered). jl. pale brown, thinly spotted with 
reddish-purple ; lip clear yellow, blotched and spot round the 
crest ; spikes short, one-flowered. Winter. h. din. Brazil, 1841. 
(B. R. 1 43.) 
O. varicosum (varicose-veined).“ fl., sepals and petals pale dull 
green, banded with dull brown; lip bright yellow, large, with two 
ovate lateral ears, somewhat crenate in front, and a four-lobed 
middle lobe; crest of two triple teeth; scapes strong, glaucous, 
about 3ft. long, having a large, branching, eighty to ninety- 
flowered panicle. J. firm, ligulate-lanceolate. A beautiful, strong- 
growing species. Brazil. See big. 733. (L. J. F. 206, 207.) 
O. v. Rogersii (Rogers’).* H. rich golden-yellow, 2in. or more in 
diameter; sepals and petals comparatively inconspicuous, the 
great attraction being the large flat lip, which is lobed in front ; 
panicle much branched, and bearing, in a well-grown example, 
as many as 170 blossoms. Winter. J. somewhat short, dark 
green. Pseudo-bulbs large, ovate, deep green. Brazil, 1869. 
This is a rare variety, and, at the same time, one of the most 
beautiful. It will succeed on a block of wood, or in a pot or 
basket; the last is, perhaps, the most convenient plan for 
displaying its large, many-flowered panicles, and, at the same 
time, it insures perfect drainage. (B. H. 1878, 172; G. C. 
1870, 277.) 
O. variegatum (variegated). fl. pink, richly stained with cinna- 
mon-red, about lin. across; panicles branching, 14ft. high, erect. 
Summer. J. dark green. h. bin. West Indies, 1824. A pretty 
species. (L. & P. F. G. 33.) [T.] 
O. vernixium (varnished). jl. disposed in a thyrsoid icle ; 
sepals and petals cinnamon-colour, with yellowish borders, 
oblong, crisped; lip yellow, remarkable for its retuse, retrorse, 
basa) auricles, the reniform apex — * and the disk shining 
brown, with a very curious callus. Ecuador, 1870. An interesting 
and distinct species. 
O. virgulatum (twiggy). A very curious species, with hetero- 
morphous flowers, and very short, numerous, zigzag branches. 
Columbia, 1876, Of no ornamental value. 
O. Warscewiezii (Warscewicz’s).* fl. golden-yellow, numerous, 
is in racemes; lip having a white, five-toothed callosity, 
with four brown spots, and both borders of its narrow bei 
tinted with brown. (. cuneate-ligulate. Pseudo-bulbs Poss 
compressed, two-leaved. Costa Rica, 1870. SYN. O. bifrons. [C.] 
O. Weltoni. See Miltonia Warscewiczii. 
O. Wentworthianum (Earl Fitzwilliam’s).* fl. lemon, 
barred towards the base of sepals, petals, and lip with Vandyke 
brown ; lobes of lip large; panicles many-flowered, remaining in 
beauty about two months. Summer. lJ. linear, lanceolate, of a 
lustrous hue. Pseudo-bulbs oblong, ovate, pale green, mottled 
amt meroa with black. Guatemala, 1839. (L. & P. F. G. ii. 
.) [C.] 
O. xanthodon (yellow-toothed). fl. very dark chocolate, with a 
very thin yellowish limb around both sepals and petals; lip dark 
brown, with a shining yellow crest and a yellow apex ; spike very 
long, trailing, branched. Winter. Z. long, linear-obovate, acute. 
Pseudo-bulbs narrow, ovoid, smooth, compressed, 5in. long. h. 2ft. 
Ecuador, 1868. (B. M. 5756.) 
O. zebrinum (zebra-marked). fl. white, transversely barred with 
reddish-violet stripes; lip yellow; racemes very long, from 6ft. 
and upwards in length. Venezuela, 1872, A pretty species. 
(B. M. 6138; I. H. 274.) 
ONCOCYCLUS. Included under Iris (which see), 
_ONCOSPERMA (from onkos, a tumour, and sperma, 
a seed; in reference to the form of the seeds). Syn. 
Keppleria. ORD. Palmee. A genus comprising five or 
six species of spiny, stolon-bearing, stove palms, natives 
of tropical Asia. Flowers unisexual, usually in threes; 
spadix shortly pedunculate; spathes two. Fruit small, 
round, one-seeded. Leaves terminal, equally pinnatisect, 
with very spiny, sheathing footstalks; segments ensiform, 
acuminate, entire. Trunks slender, spiny, marked with 
circular scars. The species thrive best in a compost of 
two parts loam, one of peat, and one of sand. They 
require a copious supply of water. Propagated by 
seeds, or by suckers. The species here described are 
probably the only ones yet introduced. 
O. fasciculatum (fascicled), Z. dark green, pinnate; pinnæ long, 
somewhat pendent; petioles sheathing, —— with slender 
black spines. Ceylon. An elegant species. 
o. filamentosum (thready). l. pinnate, from 10ft. to 12ft. long; 
pinne very numerous, narrow, drooping, about 2ft. long. h. 90ft. 
to 50 ft. Malacca, &c. SYNS. Areca Nibung and A. tigrillaria. 
O. Van Houtteanum (Van Houtte's). A _Nephro- 
sperma Van eee a ee ee 
ONION (Allium Cepa). There are few vegetable crops 
of greater importance, or more in daily request, than that 
of the Onion. Itis a native of Central Asia, &c. Until 
Onion—continued. 
recently (comparatively speaking), the origin of the plant 
was unknown. It is a hardy biennial, as, although the 
leaves and roots are only of annual duration, the bulb 
formed in the summer, after being kept for a greater or 
less time, according as the different varieties admit, has 
the power of renewing its growth by forming fresh roots 
and leaves, and producing its flowers and seeds; after- 
wards, it dies away. Onions have been cultivated from 
the most remote period, throughout an extremely wide 
geographical area. Their uses are well and universally 
known, both in the green young state, and also, more 
especially, when the bulbs are matured. Much variation 
exists in the shape and flavour of bulbs belonging to 
different varieties; some being very mild and succulent, 
while others are pungent, almost, at times, to an intense 
degree. An Onion bulb is composed of a series of con- 
centric coats, which surround its growing point, and vary 
in colour from dark red almost to white, the flavour being 
generally much stronger in the red than in the whiter- 
fleshed varieties. Propagation of the several sorts is 
readily effected by seeds, which, however, soon de- 
generate if care is not taken; in some cases, also, off- 
sets are produced, and may be utilised as a method of 
increase. 
CULTIVATION. One of the best and most open situa- 
tions in the kitchen garden should be assigned to Onions, 
as such a position is indispensable for their successful 
cultivation. They succeed best in a rich, loamy soil, some- — 
what light rather than heavy, and where the subsoil is 
of a fairly dry nature. The suitability of a light or a 
heavy soil, however, depends a good deal on whether 
the summer is a wet or a dry one; and indifferent soils 
may be much improved by the addition of suitable 
manures, and by a system of intercropping, or changing of 
ground, so that different vegetables are not grown, if it 
ean be avoided, in the same division of the garden two 
years in succession. For instance, Onions sown in 
spring could scarcely be better suited, as to position 
and soil, than by land occupied the previous year with 
Celery ; autumn-sown ones might follow Potatoes, Peas, 
Beans, or any of the Brassica tribe; and thus a change 
of crop would be effected. Especially should this change 
be allowed in the case of Onions, when the produce 
becomes cankered in any one situation, or the plants are 
attacked by the destructive maggot of the Onion Fly. 
Land intended for Onions should be well-trenched in 
the autumn, and left in ridges for the winter fully ex- 
posed to the weather, which will wonderfully ameliorate 
and improve that of a firm texture, or heavy and ad- 
hesive nature, before the seed-sowing time arrives. Where 
a crop of Celery has been grown, trenching will scarcely 
be necessary; the deep digging and manuring requisite 
for Celery culture being sufficient to intermix and change 
the position of nearly the whole of the soil. A good 
dressing of manure should be applied at trenching time, 
or dug in at the same season, if trenching is unnecessary. 
A few words on the best manures. The scrapings ob- 
tained from poultry yards, or from pigeon-houses, have 
long been considered as excellent manures for adding to 
land intended for Onions. Sheep-dung and pig-dung, where 
either can be obtained, are also powerful and good. 
Mixed farmyard: manure may be used in large quantities 
for a preceding crop, or else it should be well dug in 
during the autumn. Guano or blood should be mixed 
in a compost, if either are used; or the latter may be 
added to water, and applied in weak solutions as a liquid 
manure. Charred rubbish, wood ashes, and charcoal are 
beneficial in several ways; salt and soot are also excel- 
lent to sow with the seed, as, besides acting as a manure, 
they prevent, to a great extent, the attacks of insects. 
Spring-sown Onions. Land exposed in ridges through- 
out the winter will be in excellent condition for levelling 
down about the middle or end of February, supposing 
