AN ENCYCLOPEDIA OF HORTICULTURE. 



311 



Rockeries continued. 



Rhododendrons are well suited for the purpose, as they 

 grow tall if allowed, and their roots never spread far 

 enough to rob the rock plants, as would those of large 

 trees. To meet the requirements of the numerous sub- 

 jects available for planting on a Rockery, it is requisite 

 to provide various aspects and different kinds of soil; 

 and, in planting, a knowledge of the habit each plant 

 assumes is necessary, in order to dispose of all to 

 the best advantage for producing a future effect. A 

 general fault is to allow too little rooting space, by making 

 the pockets as the divisions between the stones are 

 generally called too small. This should specially be 

 avoided ; if roots cannot get down and establish them- 

 selves, the plants soon become dried up in hot weather, 

 particularly on sunny exposures. The class of plants 

 which thrive best on rockwork indeed, there are many 

 that could scarcely be grown except in such a situation 

 is a very extensive one, and includes a large proportion 

 of beautiful and most interesting subjects. If dwarf 

 shrubs and other plants, also hardy bulbs, are introduced, 

 the variety that may be represented in the limited space 

 which a Rockery usually affords is really surprising. 

 A very large proportion of the genera Saxifraga and 

 Sedum make excellent rockwork plants. Other remarks 

 on this subject may be found under Roclc Garden in the 

 article Garden. 



ROCKET. See Hesperis matronalis. 



ROCKET CANDYTUFT. See Iberis coronaria. 



ROCKET, DAME'S OR WiLLTi!. See Hesperis 

 matronalis. 



ROCKET. DYERS'. A common name for Reseda 

 Luteola. 



ROCKET, SEA. See Cakile. 



ROCKFOIL. A name, suggested by RuskiiL for the 

 genus Saxifraga. 



ROCK PINK. Ses Bianfhvs petrams. 



ROCK ROSE. See Cistns. 



ROD6ERSIA (named in honour of Admiral Rodgers, 

 of the United States Navy, commander of the expedition 

 during which the plant was first discovered). ORD. Sojri- 

 frageae. A monotypic genus. The species is a hardy, 

 erect, herbaceous perennial, with a thick, scaly rhizome. 

 It thrives best in a compost of rich loam and peat, and 

 may be increased by divisions. 

 R. japonica (Japanese). A synonym of R. podophylla. 

 R. podophylla (stalked-leaved). Rodgers' Bronze-Leaf, ft. of 

 a yellowish-white colour, somewhat nodding, ebracteate ; calyx 

 ery short, turbinate : lobes five, spreading, valvate ; petals 



ten ; 



five, large, alternate 



cymes scorpioid. 

 June and July. L three to 

 larger, long-stalked, pal- 



u ve, mree. mibcnuue ; ramcau ones xarzer. Jons-suUHeu, peu- 

 mately or peltately artJBctod; cauline ones thfee-lobed ; seg- 

 ments sessile, argntely serrated, incised at apex ; petioles dilated 

 at base ; stipules membranous, adnate to the petioles, h. 3ft. 

 to 4ft Japan, 1880. (B. M. 6691 ; G. C. n. s., xx. 14L) ST>. 



(named in honour of Em. Rodri- 

 guez, a Spanish physician and botanist). Burlingtonia 

 is now regarded, by the authors of the " Genera Plan- 

 tarum," as synonymous with this genus, but is kept 

 distinct in this work. ORD. Orehidecs. A genus com- 

 prising about a score of species of interesting, stove, 

 epiphytal orchids, natives of tropical America. Flowers 

 usually showy, many in a simple raceme ; dorsal sepal 

 free, petaloid, the lateral ones narrow, connate; petals 

 similar , to the dorsal sepal ; lip continuous, or very 

 shortly connate with the base of the column, the base 

 often produced into a spur, the lamina spreading, obovate 

 or obcordate, often exceeding the sepals, the disk usually 

 crested; column erect, slender, club-shaped or produced 

 into two auricles at the apex ; pollen masses two ; scapes 

 axillary under the pseudo-bulbs. Leaves oblong or elon- 



Rodrignezia continued. 



gated, coriaceous. For culture of the species described 

 below, fee Bnrlingtonia. 



R. Batemaai (Bateman's). This is the correct name of the 



plant described in this work as Burlinytonia Battmani. 

 R. caloplectron (beautiful-spun ed). JL light yellowish-white 

 twisted; lateral sepals forming a long, compressed, horn-like, 

 acute body, wrapping round the spur of the emarginate lip; 

 column square- winged ; inflorescence usually pendulous, few- 

 flowered. L solitary, thick, lanceolate, acuminate. Pseudo-bulbs 

 small, oblong-lignlate. New Grenada, 1871. 

 R. lanceolata (lanceolate). A synonym of R. tecunda. 

 R. Leeana (Lee's). JL the size of those of Eurlinfrtonia Candida ; 

 ovary light mauve ; upper sepal white, yellowish on mid-line ; 

 lateral ones white with yellow mid-line, quite connate ; petals 

 lignlate ; lip clawed, white, with two long-linear, yellow keels, 

 every keel having four small, lateral keels spreading outwards ; 

 column white, with numerous mauve spots. I. linear-ligulate, 

 acute, 1ft. long. Pseudo-bulbs ancipitous. Native country on- 

 certain, 1883. A curious and very stout specie*. 

 R. Lehmanni (Lehmann's). JL whitish-ochre, with a brown 

 wash ; odd sepal gibbous- fornicate in the middle ; lateral ones 

 combined in a narrow, falcate, spur-like organ, with a broad, 

 membranous lamina before the apex; petals cuneate-obovate, 

 emarginate ; lip having a solid, acute spur between the lateral 

 sepals, the free part clawed, suddenly enlarged in a blade, 

 blotched and spotted with cinnamon. New Grenada and 

 Ecuador, 1882. (G. C. xix. 403.) 



R. retracta (bent back), a. of a peculiar yellow.salmon colour, 

 few, in a porrect raceme ; dorsal sepal cuneate-obovate, bluntly 

 acute, the lateral ones combined into one navicular, narrow body ; 

 petals cuneate-obovate ; lip da wed, expanding: into an emarginate 

 blade, having on both sides four or five angular keels. L of 

 pseudo-bulb cuneate-oblong, acute. Pern. (Bef. B. 129.) 

 ; R. secnnda (side-flowering). A. dark rose-colour, disposed in 

 a cylindrical, recurved spike, which is longer than the leaves ; 

 sepals fornicate ; petals ovate, obtuse ; lip abruptly deflexed. 

 L lanceolate, obliquelv emarainate at the apex. Pseudo-bulbs 

 oval, compressed, h. 6in. Trinidad, 1820. (B. M. 5524 ; B. R. 

 930.) ST.VS. R. lantt-.-lata (L. B. C. 676), PUurothaUis coceinta 

 (H. E. F. 12?). 



RODS, BONING OR BORNING. These are in- 

 valuable instruments in levelling ground, or for deter- 

 ! mining heights in making an incline uniform throughout 

 They are always requisite when laying out new walks or 

 edges, levelling tnrf, ic. There are usually three made, 

 straight, and of equal length, about 3|ft. or 4ft.. and 

 provided with cross-pieces, which should be fixed in the 

 centre, and at exact right angles. Before Borning Bods 

 can be brought into use. it is necessary that two points 

 should be fixed, preferably at the extreme ends of the 

 ground to be levelled, should these not be too far apart. 

 If level pegs are inserted at these points, and two of 

 the three Bods allowed to rest on them, as many inter- 

 mediate pegs may be inserted as thought desirable 

 for guiding workmen. This is done by a third person 

 with the other Bod, who drives pegs in as he is directed 

 from one of the ends, until all the Bods are in, as 

 near as possible, a direct line. The tops of the pegs, 

 if the levelling is properly done, should then show all 

 inequalities in the soil, and represent themselves either 

 a level surface or a uniform incline, according to the 

 disposition of the ground and the comparative heights 

 of the two fixed points taken at the commencement. 

 Boning or Borning Rods of equal length can only be used 

 correctly by persons accustomed to them, as the light 

 is found most deceiving at a distance. Sometimes, one 

 of the Rods is made an inch longer, and a small sight- 

 hole pierced through the cross-piece. By using this, it 

 is possible to work with more exactness, as a workman 

 who might be able to level through a sight-hole might 

 not be able to do so correctly were all the Rods made of 

 equal length, and no sight-hole pierced. 



SODS, MEASURING. For regulating the distance 

 between rows and beds, and for marking out spaces for 

 walks between trees, &c., Measuring Rods of some de- 

 scription are indispensable. Either 10ft. or 12ft. is a 

 handy length; the first foot length should be marked in 

 inches, and all the others at intervals of Sin. Straight 

 Rods lin. square are suitable. 



ROEBUCK BERRY. The fruit of Rubus taxatHit. 



