AXD GENERAL HORTICULTURE. 



373 



RIG 



all danger from frost is past. Introduced in 

 1548. 



Rigide'lla. From rigidus, stiff; in allusion to 

 the stiffness of the flower stalk when support- 

 ing the seed-vessels. Nat. Ord. IridacecB. 



A small but very beautiful genus of plants, 

 natives of Mexico. R.Jlammea, is one of the 

 most interesting species. It grows from thi-ee 

 to five feet high, with very broad and curi- 

 ously plicate leaves, which look as though 

 thej' had been regularly plaited artificiallj*. 

 The flowers are numerous, of a bright flame 

 color, all issuing from one spathe, and open- 

 ing onlj' one at a time. The plant is of easy 

 culture, requiring in all respects the same 

 treatment as the Tigridia. Introduced into 

 Britain in 1838. 



Ringed. Surrounded by elevated or depressed 

 circular lines or bauds, as the roots or stems 

 of some plants, the cups of several species of 

 Quercus, etc. 



Ringeut. Gaping, like the mouth of a bilabiate 

 corolla, as Antirrhinum. 



Riparious. Growing on the banks of rivers or 

 lakes. 



Ripo'gonum. See Rhipogonum. 



Ri'vea. Named after A. de la Rive, a botanist 

 of Geneva. Nat. Ord. ConvolvulacecB. 



Very beautiful green-house evergreen twin- 

 ers, allied to Ipomcea, natives of the East 

 Indies. The ease with which the many an- 

 nuals of this natural order are grown causes 

 the more tender kinds to be neglected, or lost 

 sight of altogetlier. R. hypocraferiformis 

 (salver-shapedj, the Midnapore Creeper, has 

 large, pure white flowers, expanding at sunset, 

 with a fragrance resembling that of the finest 

 cloves. Don says this species is the prince of 

 convolvulaceous plants. 



Rivi'na. Named after A. Q. Rivimis, a botanist 

 of Saxony. Nat. Ord. Phytolaccacece. 



Green-house evergreen shrubs, natives of 

 South America and the West Indies. R. 

 humilis is commonly grown in green-houses 

 for its beautiful racemes of little bright scar- 

 let berries. It is called in the West Indies 

 Rouge Plant, the juice of the berries being 

 used as a cosmetic. R. rividarbi, is a stronger- 

 growing plant than the above, but in other 

 respects is much the same. Propagated by 

 seeds or from cuttings. Introduced in 1804. 

 Syn. Piercea. 



Roast-beef Plant. A common name for Iris 

 fce,tidissima. 



Robi'nia. Locust Tree. Honey Bean. Named 

 in honor of Jean Robin, a French botanist, 

 once herbalist to Heniy IV. of France. Nat. 

 Ord. LeguminoscB. 



R. Pseudacacia, False Acacia, is the com- 

 mon Yellow Locust, indigenous to thn Middle 

 and Southern States. It is extensively grown 

 in many parts of the country for the valuable 

 timber it furnishes, as being the most durable 

 of all wood for posts, or whore it comes in 

 contact with the earth. It is one of our most 

 valuable lumber trees, and is largely used for 

 various mechanical purposes. R. hispida, or 

 Rose Acacia, is a handsome shrub, with long 

 racemes of beautiful rose-colored flowers 

 without fragrance ; a maiked contrast to the 

 foregoing species. It is a native of the South- 



ROC 



ern States, from Virginia southward ; is com- 

 monly cultivated with ornamental shrubs. 



Rocambole. (Alliu7n Scorodoprasum). A hardy 

 perennial, cultivated for the use of its bulbs in 

 a somewhat similar way to those of Garlic. 

 Increase is effected by dividing the bulbs, 

 which form annually, at the root, and also on 

 the top of the stems. 



Ro'chea. N amed after M. de la Roche, a botan- 

 ical writer. Nat. Ord. CrassulacecB. 



A genus of green-house evergreen succu- 

 lents, allied to Crassula, and requiring the 

 same general treatment They are natives of 

 the Cape of Good Hope. Several of the spe- 

 cies are under cultivation, their singular 

 leaves and bright flowers making them attrac- 

 tive specimens. R. falcata, one of the best, 

 is propagated by cuttings. Kalosanthes (Cras- 

 sula) coccinea is placed under this order by 

 several authorities. 



Rock Beauty. A common name for Draba 

 Pyrenaica. 



Rock-Cress. See Arabia. 



Rocket. See Hesperis. 



Rocket. Candytuft. Iberis coronaria. 



Rocket. Dyer's. Reseda luteola. 



Rocket. Larkspur. Delphinium ajads. 



Rock Lychnis. See Viscaria. 



Rock Rose. See Cisttis. 



Rock Gardens. These may be looked upon as 

 comparatively modern institutions, while 

 Rockeries are of ancient date. The latter are 

 excellent in their way, but depend much on 

 the nature of the material at the command of 

 the operator, and on being constructed in 

 such a manner as to produce a landscape 

 effect. Although in Rock Gardens the ar- 

 rangement and formal distribution of the 

 plants are specially to be considered, it is, 

 however, unnecessary that artistic effect 

 should be altogether ignored, for it is quite 

 possible to have a graceful arrangement with- 

 out sacrificing the individual health and habit 

 of the plants. Many of the best and rarest 

 species will not succeed as well elsewhere as 

 they do among the crevices on an elevated 

 and well-drained piece of rock-garden, which, 

 in addition, affords a situation for an endless 

 variety of hardy and half-hardy plants. 



The late Mr. Hanson, after trying many 

 locations and aspects, found he could grow 

 many of the rarer Lilies to the best advantage 

 when planted close by large stones in his 

 rock-garden, which, indeed, he made specially 

 for them. 



There are few gardens where something of 

 this sort might not be constructed and ren- 

 dered attractive, especially in localities where 

 stones are plentiful. It may be introduced 

 for various reasons, such as hiding any un- 

 sightly object of limited height, or for giving 

 diversity to an otherwise flat and uninterest- 

 ing scene, or for giving a reason for a curved 

 line — for there should be no deviation from a 

 straight line in the garden unless for cause. 

 It may also be successfully formed where the 

 surface is generally flat by digging a deep 

 cutting of an irregular outline through a 

 piece of ground, and utilizing the soil thus 

 obtained as mounds of uneven heights along 

 the upper parts on either side, whereon dwarf 



