ONC'lDIUM. 



195 



ONO'SMA. 



Old Man's Beard. See Geropo- 

 gon. 



Oleander. — See Neri'um. 



Onc'ibium. — Orchidacece. — Well- 

 known orchideous plants -with very 

 curious flowers. O. papilio, the 

 butterfly plant, is certainly as much 

 like a butterfly as it is possible to 

 imagine a flower to be ; and as it is 

 borne on a long slender stem, which 

 quivers with every breeze, it forms no 

 bad representation of a beautiful in- 

 sect fluttering over the neighbouring 

 flowers. O. altissimum has a spike 

 of flowers which is sometimes ten or 

 twelve feet in length. All the kinds 

 are very handsome, and some of them 

 are splendid. They are all natives of 

 South America, Mexico, and the 

 West Indies ; and as they will thrive 

 in a much lower temperature than the 

 dendrobiums, and some of the other 

 orchidaceas, they are very suitable for 

 a small hothouse. All the kinds may 

 be grown in pots, though some of the 

 smallest appear to thrive most tied on 

 pieces of wood and hung from the 

 rafters. The soil should be turfy 

 peat, broken in pieces about the size 

 of gooseberries, and mixed with an 

 equal quantity of potsherds broken 

 somewhat smaller. The pots should 

 be large, and filled a third of their 

 depth with broken potsherds rather 

 larger than those mixed with the soil. 

 Great care should be taken in repot- 

 ting any of the Oncidiums, as the 

 roots will be found to adhere strongly 

 to the sides of the old pot, and thus 

 are easily broken. To prevent this, 

 the plants should be shifted as seldom 

 as possible ; and when shifting is in- 

 evitable, they should be kept without 

 water for several days beforehand, so 

 that the plants may be in a flagging 

 and feeble state, and their roots have 

 less power of adhesion. All the On- 

 cidiums should be regularly watered, 

 but they should not often be syringed 

 overhead, as they are very apt to rot 



if any water should lodge in the 

 centre, or what gardeners call the 

 heart, of the plant. 



The commonest kinds of Oncidium 

 are, O. flexubsum, a very beautiful 

 species, with a long, much-branched 

 panicle of bright yellow flowers ; O. 

 crispum, the flowers of which are of 

 a copper colour, and much undulated 

 or curled ; O. altissimum, with a 

 very long flower-stem, somewhat 

 branched, and with yellow flowers 

 spotted with brown ; O. luridum, 

 with a panicle of greenish brown 

 flowers ; and O. papilio, the flowers 

 of which are borne singly, on long, 

 simple, and naked stalks. Besides 

 these, there are many species nearly 

 allied to 0. altissimum and O. lii- 

 ridum and there are also some 

 dwarf species, such as O. triquetrum 

 and O. raniferum, the latter having 

 drooping racemes of very small 

 flowers. The colours are generally 

 yellow and brown ; but O. pulch il- 

 ium, a very beautiful species, has 

 white flowers tinged with pink, and 

 O. triquetrum has white flowers 

 blotched with purple. O. raniferum 

 should be grown on a piece of wood 

 hung from the rafters ; and O. pa- 

 pilio, and some of the other species, 

 may be treated in the same manner. 



Onobrv v chis. — Leguminosce. — 

 Saintfoin. Hardy perennial plants, 

 some of the species of which are pretty 

 and suitable for rockwork. 



Ono'nis. — Leguminosce. — The 

 Rest Harrow. Little herbaceous and 

 shrubby plants, some of which are 

 natives of Britain, and which have 

 generally yellow or pink flowers. Most 

 of the kinds should be grown in peat, 

 or in very sandy loam ; and they are 

 all suitable for rockwork. Some of 

 the kinds from the south of Europe 

 are rather tender ; but they will all 

 live in the open air, with a very slight 

 protection, during hard frosts. 



Ono'sma. — Boraginecs. — Peren- 

 o 2 



