288 



The Dictionary of Gardening, 



Rhapis — continued. 



partetl ; segments sub-plicate, cili:ite-spinuIose along the edges 

 and keel of the plaits, indented-erose at the end ; petioles 

 round-ancipital, naked, very obscurely denticulate. Stem about 

 lift, high, as thick as the thumb, sluathed by the reticulated, 

 persistent bases of the leaves, (liina and Japan, 1774. See Fig. 

 365. (IJ. M. 1374.) Svn. R. aapcm. 

 R. f. foliis-variegatis (variegated-leaved). A form in which 

 the leaf-segments are more or less freely striped with white. 

 Japan. 1861. 

 R. humilis (low-growing). I. cut into from seven to ten spreading 

 st-ynu-iits ; pL-tidles unarmed. Similar in general aspect to 

 J!.' lliihrUtfoniii.s. Japan. SVN. it'. A'f roi.v/A- (of gardens), 

 R. SirotSik (Simtsik). A garden synonym of li. hiimilin. 



BHAFONTICUM (from Rha, the old Greek name for 

 Rhubarb, and FoniiruK, of Pontus. It was also called 

 Rhemn barbarum. See Itheum). Ord. Co-}nposihTj. A 

 genus comprising' about half-a-dozen species of annual or 

 perennial herbs, of w^hich the best known is described 

 below. Rluiponficmn is included, by Bentham and Hooker, 

 under Centaurea (which see for culture). 



R, scariosum (scarious). J}.-hrads purple ; outer involucral 

 scales all scariiius, sub-entire or at length cut; inner ones 

 narniwer and very acuminate. July. I. glabrous above, cano- 

 tuiiifiitnse beneath ; lower ones petiolate, ovate or cordate, den- 

 ticulate ; middle ones shortly petiolate. ovate-oblong ; uppermost 

 ones sessile, oblong, acuminate at both ends, scarcely toothed. 

 k. 2ift. Switzerland, &c., 1640. (B. M. 1752, undername of Cen- 

 tmura Rhapoiitica.) 



BHATAKY HOOT. The root of Krameria 

 triandra (which set:). 



RHEA. A common name for Bcehmeria nivea. 

 RHEEDIA (called after Hen. van Rheede, 1635- 



1691, a Dutchman residing" at Malabar, author of 

 *' Hortus Malabaricus "). Ord. Gnffiferce. A genus 

 embracing nineteen species of stove trees, inhabiting 

 Madagascar and tropical Africa and America. Flowers 

 usually rather small ; sepal.s two ; petals four ; peduncles 

 axillary or lateral, one-flowered. Leaves rigidly coria- 

 ceous, slenderly penniveined. The species are of little 

 or no horticultural interest. 



RHRUlhl (from rheon, an adjective formed from 

 R}i(i, the old Greek name for Rhubarb. Rheon bar- 

 barum has been corrupted into our Rhubarb). Rhubarb. 

 Ord. Polygonece, About a score species have been 

 referred to this genus, but the number may be reduced ; 

 they are hardy, robust, perennial herbs, with thick and 

 slightly woody rhizomes, natives of Siberian, Himalayan, 

 and Eastern Asia. Flowers pedicellate, fasciculate, 

 ebracteolate, the fascicles disposed in narrow, paniculate 

 racemes ; perianth of six spreading segments. Leaves 

 large, sinuate-toothed or palmately lobed, three to eight- 

 nerved at base. R. Rhaponficum and its varieties, and 

 R. undalatum, furnish the rhubarb so well-known and 

 extensively employed. Several of the species are very 

 handsome, both in their foliage and in their inflorescence. 

 The rhubarb of commerce, an important medicine, valu- 

 able for its mild purgative properties, is afforded by 

 several species of Rlieiini, of which the following are the 

 principal: 1. R, jiahmtlum, Hn^t found wild in 1872-3, by 

 Colonel Prejavalsky, in the Tangut district of Kansu, 

 the extreme north-western province of China ; this is 

 the real source of the Russian, or Turkey, Rhubarb. 2. 

 R. officinale, from the Chinese frontier of Eastern 

 Thibet. 3. R. Rhaponticum, generally called English 

 Rhubarb, a native of Southern Siberia, known to have 

 been cultivated, early in the seventeenth century, at 

 Padua, whence it was brought to England, tlie first 

 plant being raised about the year 1628. It is largely 

 cirltivated at Bodicott for medicinal purposes. A selec- 

 tion of the best-known species is given below. Any of 

 them are well woi-thy of cultivation as hardy, fine-foliaged 

 plants, for wild gardens, margins of shrubberies, &c. They 

 succeed in almost any soil, but do best where it is rich, 

 and of a good depth. Propagated by seeds, and by 

 division. For culture of the well-known garden varieties, 

 see Rhubarb. 



Rheum — continued. 



R. acuminatum (taper-pointed), jt. lurid-purple, blooJy, or 

 liruwiiisli-purple, i'lu. in diameter, spreading ; panicle slightly 

 branched. /. broadly cnrdate, with a deep sinus, long-acuminate, 

 opaque above, pulieruluus below ; petioles slender, concave 

 al)Ove. Root slender, often many feet long. /*, 3ft. Sikkim, 

 1837. (B. M ^877.) 



B, australe (Southern), fl. in a long, racemiform, dense panicle ; 

 calyx purple. I. sub-orbicular, broadly cordate, obtuse, fiat, Sin. 

 to 4in. long, nearly 3in. broad ; petioles 4in. long, slender, 

 slightly terete, augidute-suk-ate. Stem 6ft. to 10ft. high, leafv. 

 Root fusiform, branched. Nepaul. (S. B. F. (1. 269.) 



R. Emodi (Kmodus). Jl. whitish, in a fastigiate, dense panicle. 

 /. broad-ovate, obtuse, cordate, with slightly wavy margins, five 

 to seven -nerved ; petioles semi-terete. Stem tall, leafy, h. 6ft. 

 to 10ft. Himalaya. 



R. nobile (noble).* /I. green, insigniflcant, in short, branched 

 panicles; bracts delicate straw-cidour, shining, semi-transparent, 

 concave, imbricating, cnnctaling the flowers, the upper ones with 

 pink edges. I., radical ones large, bright glossy green, with red 

 petioles and nerves ; stipules pink, fragile. /*. upwards of 3ft. 

 Hoots thick, fleshy, sometimes many feet long. Sikkim. A 

 lovely species. ((J. C. n. s., iii. 91.) 



R, officinale (officinal).* /l. greenish, small, collected into dense 

 spikes. /. large, smnewhat orbicular-reniform, five-nerved, and 

 cut into fivL' short Inlies at the margin ; lobes unequally incised. 

 Stem 8ft. to 10ft. high, leafy and much-brancbed. Thibet, 1871. 

 A stately plant. (B. M. 6135; B. i\I. 1*1. 213: R. H. 1871, 13.) 



R. palmatum (palmate-leaved). //. in a leafy panicle. I .sub- 

 orhicular cordate, palmately lobed, slightly scabrous or glabrous 

 above, three to five-nerved ; lobes ovate-oblong or lanceolate, 

 acute, undivided, or incised-toothed or pinnatitid ; petioles nearly 

 eylindric. li. 5ft. East and North Asia. 1763. (B. M. PI. 214.) 



R. Rhaponticum (lifta ponticum—i.e.. Pontic Rha or Rheum, 

 the name of the drug Rhubarb in the Latin medical writers — 

 applied to the present species by the old botanists). Common 

 cultivated Rhubarb, ,/f. tlensely disjiosed in a leafy, fastigiate 

 panicle. I. sub-orbicular, profoundly cordate, undulated, five- 

 nerved, glabrous above, puberuhuis below and du the veins ; 

 upper ones ovate or acuminate; footstalks hing, thick, and 

 fleshy, channelled above, and roumled at the edges. /(. 4ft. 1573. 

 (B. M. PI. 215.) 



CiLV 



Eheum undulatum. 



R. undulatum (undulated). /. densely disposed in a fastigiate 

 panicle, wliirh is leafy below. I. ovate-cordate, undulated. Ave 

 to seven-nerved, glabrous above, puberulous beneath ; uppermost 

 ones sub-sessile, two or three times longer than broad ; petioles 

 semi-terete, loosely channelled above, with rounded margins. 

 Stem 4ft. to 5ft. high, smooth, green. Siberia, &c., 1734. See 

 Fig. 364. 



