AN ENCYCLOPEDIA OF HORTICULTURE. 



501 



Ophrys continued. 



broadly margined with maroon-purple. 1. linear-oblong. Stem 



4in. to 12in. high, bearing several flowers. South Europe, 1818. 



(B. M. 5844 ; B. R. 370.) 

 O. tenthredinifera (sawfly- bearing). /. varying in colour; 



petals spreading ; lip villous, oblong, obovate, the apex bilobed, 



appendiculate. April and May. Stems leafy, h. 9in. South 



Europe, 1815. (B. M. 1930 ; B. B. 205, 1093.) 

 O. vespifera (wasp-bearing). A synonym of 0. lutea,. 



OPLISMENUS (from hoplismenos, awned; referring 

 to the awns). SYNS. Hekaterosachne, Orthopogon. OED. 

 Graminece. A small genus (three or four species) of 

 stove or greenhouse Grasses, allied to Panicum, broadly 

 dispersed over the tropical and sub-tropical regions of 

 the globe. Spikelets one-flowered, articulated with the 

 pedicel; glumes four; panicles unilateral. Leaves nar- 

 rowly or broadly lanceolate, flat. These somewhat large- 

 leaved grasses are of easy culture ; they grow freely 

 in a mixture of loam, leaf mould, and sand, and make 

 nice plants for table decoration, &c. They are propagated 

 by division ; or by seeds, which are freely produced. 

 The two species mentioned below succeed either in the 

 stove or greenhouse. 



O. hirtellus (slightly-hairy).* JL, sheath pilose ; spikes distant ; 

 common axis pubescent ; spikelets three to ten, pubescent ; lowest 

 awn smooth, bluntish, three to five times as long as its glume ; 

 third glume shortly awned, furnished with a palea. June and 

 July. 1. lanceolate, acuminate, undulate, puberulous, IJin. to 

 2iin. long. West Indies, 1795. SYN. Orthopogon hirtellus. 



O. loliaceus (Tares), fl., sheath glabrous, ciliate or pilose ; spikes 

 usually oblong ; common axis nearly glabrous ; spikelets fascicled ; 

 lowest awn three or four times as long as its glume ; third glume 

 shortly awned, furnished with a palea. July and August. 1. ob- 

 long-lanceolate or lanceolate, acuminate, 2in. to 4in. long. Trini- 

 dad, 1820. SYN. Orthopogon loliaceus. 



OPLOTHECA (of Nuttall). Included under Frce- 

 lichia. 



OFOFONAX CHIRONIUM. A synonym of Mala- 

 baila Opoponax (which see). 



OPORANTHUS. Included under Sternbergia 

 (which see). 



OPPOSITE. Placed on opposite sides of some other 

 body or thing, and on the same plane. 



OPUNTIA (the old Latin name used by Pliny, and 

 said to be derived from the city of Opus). Indian Fig; 

 Prickly Pear. ORD. Cactece. A genus of greenhouse, or 

 hardy succulent trees or shrubs, natives of the tropical and 

 warm regions of America; some of the species have become 

 widely naturalised in the Old World. About 150 species 

 have been described, but many of these are not sufficiently 

 distinct to merit specific rank. Flowers yellow, red, or 

 purple, lateral; calyx tube not produced above the ovary; 

 lobes numerous ; petals numerous, connate at base, spread- 

 ing ; stamens many-seriate. Berry pear-shaped, tubercled. 

 Leaves scale-like, deciduous. Stem terete at base, 

 branched ; branches articulated, flat, compressed, globose 

 or sub-cylindrical, tubercled; tubercles tomentose, spiny, 

 the young ones leafy. 



The cultivation of Opuntias is very easy. All that is 

 necessary for plants in pots is to secure thorough drain- 

 age, and givo all the light possible. Formerly, broken 

 brick rubbish was supposed to be essential to their 

 well-being, but good loam alone will do quite well. 

 Powdered bricks, mixed with the loam, however, suit 

 the smaller-growing kinds, and insure rapid drainage. 

 During winter, a smaller supply of water is required ; 

 indeed, when at rest, the plants should be kept almost 

 dry. The hardy species are extremely interesting, and 

 grow freely in sunny spots in the open air, provided 

 some means be adopted to guard against superabundance 

 of moisture. Some of them, in their native habitats, 

 withstand much more cold than ever is experienced in 

 Britain; but the dry air, or the covering of snow, pro- 

 tects them. An ordinary hand-light, placed over the 

 plants, is shelter enough, provided the position in which 



Opuntia continued. 



they are placed is dry and efficiently drained. Opuntias 

 may be propagated by means of the branches, or portions 

 of them; these should, after being cut off, be laid on a 

 dry shelf for a time, and then planted or laid on well- 

 drained pots of loam and brick- dust ; but very little 

 water should be given until roots are emitted. Seeds, 

 too, are readily raised ; the appearance of the seedlings 



FIG. 749. SEEDLING OPUNTIA, showing Mode of Germination. 



is shown in Fig. 749. The following extracts from the 

 " Transactions of the Horticultural Society " are interest- 

 ing as showing what may be done in a Surrey garden ; 

 they are from a paper " On the Treatment of the Cactus 

 Opuntia, or Prickly Pear ; under which it will perfectly 

 mature its fruit in the open air of England," read on 

 3rd Sept., 1816, communicated by Mr. John Braddick, 

 Thames Ditton : " Having heretofore observed that the 

 plant, in its wild state, delighted in a dry soil amongst 

 rocks near the skirts of the sunny sides of the forests 

 [the writer is speaking of Virginia], I, in consequence, 

 planted it in the compost described below, placed in a 

 sheltered position open to the sun. The first plant that 

 I turned out has lived in the open ground of this country 

 for six or seven years, during which period it has 

 endured one exceeding hard winter, and several trying 

 springs; and in all, except the first two years, it has 

 never failed to ripen its fruit and seeds, so that it may 

 be now considered decidedly naturalised. It is now 

 growing vigorously ; and, although the present season 

 has been decidedly unfavourable, yet I doubt not but it 

 will produce a plentiful crop of flowers, and ripen its 

 fruit fit for the table during the course of the next 

 month. . . . The compost used by me for growing 

 the Cactus Opuntia is the following: One half is car- 

 bonate of lime, for which lime rubbish from old build- 

 ings will answer; the remaining half consists of equal 

 portions of London clay and peat earth, having the 

 acid neutralised by barilla; these are intimately blended 

 I and sifted. One square yard of this compost I conceive 

 to be sufficient for one plant, which must be placed in 



I' the middle of a small artificial hillock, raised eighteen 

 inches above the surface of the ground, which ground 

 should be rendered perfectly dry, if not naturally so, 

 by under- draining. Neither the leaves, flowers, nor 

 fruit should ever be suffered to touch the ground ; but 

 they should, as constantly as they are produced, be kept 

 from the earth, by placing stones, pebbles, flints, or 



