AND GENERAL HORTICULTURE. 



383 



ROS 



Rose Geranium. See Pelargonium. 



Hose Mallow. Hibiscus coccineus. 



Rosemary. See Rosmarinus. 



Rose of Heaven. Lychnis cceli-rosea. 



Rose of Jericho. See Anastatica. 



Rose of Sharon. Hibiscus Syraicus. 



Rose Root. Sedum Rhodiola. 



Rosewood. A valuable South American tim- 

 ber, produced from several species of Dalber- 

 gia. The finest quality is from Rio Janeiro, 

 the product of D. nigra, which see. 



Rosin Plant, or Rosin Weed. See Silphium. 



Rosmari'nus. Rosemary. From ros, dew, and 

 marinus, of the ftea ; on account of its mari- 

 time habitat. Nat. Ord. Labiatce. 



The Rosemary is a half-hardy, low-growing 

 evergreen, a native of the south of Europe. It 

 has long been cultivated and valued for the 

 essential oil it yields. The whole plant is 

 aromatic, but the flowers, which are pale 

 blue, are chiefly used in distillation for the 

 oil, which is the principal ingredient of Hun- 

 gary Water and Eau de Cologne. There are 

 several varieties under cultivation in the gar- 

 dens, R. qfficinalis being the more common 

 species. Propagated by cuttings. 



Rostellum. A narrow extension of the upper 

 edge of the stigma of certain Orchids. 



Rostrate. Terminating gradually in a long, 

 straight, hard point, like the pod of a Radish. 



Rosulate. Collected in a rosette. 



Rotate. Resembling a wheel. 



Rotation of Crops. All observing cultivators 

 soon discover, that no matter how fertile a 

 soil may be, the same kind of crop cannot be 

 grown so well on it successively as if it were 

 alternated with a crop of an entirely different 

 character. No satisfactory reason can be 

 assigned for this that we know of, unless in 

 the familiar case of the Cabbage crop. We 

 find that if Cabbages on most soils are grown 

 two years in succession, the crop will be 

 affected by the disease known as " Club 

 Root" (which see) ; but in this particular in- 

 stance we get at a tangible cause. A great 

 many theories have been assigned why the 

 same crops deteriorate by being grown suc- 

 cessively on the same soil, but they have been 

 far from satisfactory, and in no case that we 

 know of, unless in the case of the Cabbage, or 

 Brassica tribe, have they led to any beneficial 

 practical results. The following general rules 

 have been laid down as a guide : 



First. Plants of the same natural order 

 should not be planted to succeed each other. 

 Second. Crops which for a number of years 

 occupy the ground, such as Strawberries, 

 Rhubarb, or Asparagus, should be succeeded 

 by annual crops, such as Cabbages, Lettuce, 

 or Radishes. Third. Crops grown for their 

 heads, such as Cabbage, Cauliflower, or Let- 

 tuce, should be succeeded by plants grown 

 for their roots, such as Parsnips, Carrots, or 

 Beets. It is not always practicable to vary 

 crops according to rules, nor should such 

 rules be taken as arbitrary, but only as a 

 guide. When vegetables or fruits are grown 

 for market, the necessities of the cultivator 

 compel usually double crops of the land each 

 season, and that, with heavy manuring and 

 deep cultivation, seems to do away, to a con- 



ROX 



siderable extent, with any need for systematic 

 rotation, which would often be found to be 

 impracticable. As has been previously said, 

 the crops of all others that we find most ben- 

 efited by change are the Cabbage tribe, to- 

 gether with the allied families of Turnip, 

 Radish, etc. ; while, on the other hand, 

 Onions never seem to be injured by succes- 

 sive plantings on the same soil. When space 

 is limited, or when it is not convenient to 

 rotate crops, the next best thing is deep cul- 

 ture, by trenching or sub-soiling (which see). 

 The same method holds good for farm as well 

 as for garden crops. It is not advisable to 

 follow such crops as wheat or corn year after 

 year on the same land ; wheat particularly 

 being a great feeder, the land would soon be- 

 come exhausted. Another reason is and it 

 is true of a great many other crops that 

 when one of the same kind is continuously 

 sown, there is far more danger of injury by 

 insects or blight, as it seems to be a law of 

 nature that special plants are subject to the 

 ravages of special insects or diseases, and the 

 best way to get relief from their attacks is to 

 change the crop as radically as possible ; thus 

 a grain crop might be followed by one of Po- 

 tatoes, Mangels, Peas, or Beans ; this in turn 

 by grass, if used, or by a change from one or 

 other of the foregoing to Celery, Onions, or 

 Cabbages. Carrots, Parsnips, or other mem- 

 bers of that order should never follow each 

 other ; but if similar crops have of necessity 

 to succeed each other, the ground should be 

 deeply plowed and well manured between the 

 crops. 



Rotund. Rounded in outline ; usually applied 

 to bodies which are not round themselves, 

 but only at their ends. 



Rouge Plant. See Rivina humilis. 



Roupa'la. Said to be the native name in Guiana. 

 See Rhopala. 



Roupe'llia. Named in honor of Charles Roupell, 

 a distinguished botanist of South Carolina. 

 Nat. Ord. Apocynacece. 



This is the far-famed Cream-fruit tree of 

 Sierra Leone, a remarkable and showy green- 

 house climber. In its native home it is a 

 most beautiful and fragrant plant, but under 

 artificial cultivation its pure white flowers are 

 of cream color, and it is in all respects infe- 

 rior to the flattering accounts given by its 

 discoverer, and not worth the care and atten- 

 tion required to grow it. 



Rowan-Tree. A popular name for Pyrus Aucu- 

 paria. 



Roxbu'rghia. Named after Dr. Roxburgh, once 

 director of the Botanic Garden, Calcutta. Nat. 

 Ord. RoxburghiacecB. 



A genus of evergreen, twining or half 

 shrubby plants, natives of India and tropical 

 Australia, with broad, shining leaves, and 

 peculiar green flowers which are produced 

 singly and in small clusters on short, axillary 

 peduncles ; they are large and handsome, but 

 very fetid, and this disagreeable feature 

 prevents their introduction into choice collec- 

 tions of hot-house plants. 



Roxburghia'ceae. A natural order of twining 

 or erect, half-shrubby plants, natives of tropi- 

 cal Australia, India, and the Indian Archi- 

 pelago. The thick, tuberous roots of some of 

 the species are, after a previous preparation 



