AN ENCYCLOPEDIA OF HORTICULTURE. 



491 



Oncidium continued. 



O. uniflorum (one-flowered), ft,, pale brown, thinly spotted with 

 reddish-purple ; lip clear yellow, blotched and spotted round the 

 crest ; spikes short, one-flowered. Winter, h. 4in. Brazil, 1841. 

 (B. R. 1843, 43.) 



O. varicosum (varicose-veined).* rl., 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. I. firm, ligulute-lanceolate. A beautiful, strong- 

 growing species. Brazil. See tig. 733. (L. J. F. 206, 207.) 



O. v. Rogers!! (Rogers').* fl. 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. I. 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 i 

 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), JL pink, richly stained with cinna- 

 ed, about lin. across ; panicles branching, lift, high, erect. 



Summer. I. dark green. A. 6in. 

 species. (L. & P. F. G. 33.) [T.] 



O. vernixium (varnished). JL disposed in a thyrspid panicle ; 

 sepals and petals cinnamon-colour, with yellowish borders, 

 oblong, crisped ; lip yellow, remarkable for its retuse, retrorse, 

 basa) auricles, the reniform apex yellow, 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- 

 morpnous flowers, and very short, numerous, zigzag branches. 

 Columbia, 1876. Of no ornamental value. 



O. Warscewiczli (Warscewicz's).* JL golden-yellow, numerous, 

 disposed in racemes ; lip having a white, flve-toothed callosity, 

 with four brown spots, and both borders of its narrow part being 

 tinted with brown. /. cuneate-ligulate. Pseudo-bulbs ovoid, 

 compressed, two-leaved. Costa Rica, 1870. SYN. 0. bi/rvns. [C.] 



O. Weltoni. See Miltonia Warscewiczli. 



O. WentwortManum (Earl Fitzwilliam's).* fl. pale 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. I. linear, lanceolate, of a 

 lustrous hue. Pseudo-bulbs oblong, ovate, pale green, mottled 

 and barred with black. Guatemala, 1839. (L. & P. F. G. ii. 

 127.) [C.] 



O. xanthodon (yellow-toothed). /. 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. 1. long, linear-obovate, acute. 

 Pseudo-bulbs narrow, ovoid, smooth, compressed, Sin. long. h. 2ft. 

 Ecuador, 1868. (B. M. 5756.) 



O. zebrinum (zebra-marked). JL white, transversely barred with 

 reddish-violet stripes ; lip yellow ; racemes very long, from 6ft. 

 and upwards in length. Venezuela, 1872. A pretty species. 



reddish-violet stripes ; lip 

 and upwards in length. 

 (B. M. 6138; I. H. 274) 



ONCOCYCLT7S. Included tinder Iris (which see). 



ONCOSFERMA (from onkos, a tumour, and aperma, 

 a seed ; in reference to the form of the seeds). SYN. 

 Keppleria. OBD. Palmae. A genus comprising five or 

 six species of spiny, stolon-bearing, store 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). I. dark green, pinnate ; pinnre long, 



somewhat pendent ; petioles sheathing, clothed with slender 



black spines. Ceylon. An elegant species. 

 O. filamentosum (thready). I. pinnate, from 10ft. to 12ft. long ; 



pinnae very numerous, narrow, drooping, about 2ft. long. h. 40ft. 



to 50ft. Malacca, Ac. SYNS. Areca Nibung and A. tigillaria. 

 O. Van Houtteanum (Van Houtte's). A synonym of Nephro- 



tperma Van Houtteanum. 



ONIME BOOT. See Flectranthus ternatus. 



ONION 1 (Allium Cepa). There are few vegetable crops 

 of greater importance, or more in daily request, than that 



Onion continued, 



I of the Onion. It is a native of Central Asia, &c. Until 

 ] 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 leave?, 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 espe- 

 cially, 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 concentric 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 degenerate if care is not taken ; 

 in some cases, also, offsets 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 

 can 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- 

 I 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 

 i 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 



