THE DICTIONARY OF GARDENING, 



Shapis continued. 



parted ; segments sub-plicate, ciliate-spinnlose along the edges 

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

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

 14ft. high, as thick as the thumb, sheathed by the reticulated, 

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

 363. (B. M. 1374.) SYN. R. aspera. 



B. t. foliia-vartegatls (variesated-leaved). A form hi which 

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

 Japan. 1861. 



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

 segments; petioles unarmed. Similar in general aspect to 

 R. flabellifwmi*. Japan. SYN. R. Sirotsik (of gardens). 

 B. Sirotsik (Sirotsik). A garden synonym of R. humilis. 



RHAPONTICUM (from Rha, the old Greek name for 

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

 Rheum barbarum. See Rheum). ORD. Composite. A 

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

 perennial herbs, of which the best known is described 

 below. Rhaponticum is included, by Beutham and Hooker, 

 under Centaur ea (which see for culture). 

 B. scarlosum (scarious). fl. -lit ads purple ; outer involucral 

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

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

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

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

 ones sessile, oblonor, acuminnte at both ends, scarcely toothed. 

 A. 2Jft. Switzerland, &c., 1640. (B. M. 1752, under name of Cen- 

 taurea Rhapontica.) 



RHATANY SOOT. The root of Xrameria 

 triandra (which see). 



RHEA. A common name for Bcehmeria nivea. 

 RHEEDIA (caUed after Hen. van Eheede, 1635- 

 1691, a Dutchman residing at Malabar, author of 

 "Hortus Malabaricus"). OKD. Outtiferae. A genus 

 embracing nineteen species of stove trees, inhabiting 

 Madagascar and tropical Africa and America. Flowers 

 usually rather small; sepals two; petals four; peduncles 

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

 ceous, slenderly penniveined. The species are of little 

 or no horticultural interest. 



RHEUM (from rheon, an adjective formed from 

 Rha, the old Greek name for Rhubarb. Rheon bar- 

 barum has been corrupted into our Rhubarb). Rhubarb. 

 OBD. 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, tnree to eight- 

 nerved at base. 12. Rhaponticum and its varieties, and 

 JR. undulatum, 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 Rheum, of which the following are the 

 principal : 1. R. palmatum, first 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, the first 

 plant being raised about the year 1628. It is largely 

 cultivated at Bodicott for medicinal purposes. A selec- 

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

 them are well worthy 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, 

 t Rhubarb. 



Rheum continued. 

 I. acuminatum 



inatnm (taper-pointed), fl. lurid-purple, bloody, or 

 brownish-purple, in. in diameter, spreading ; panicle slightly 

 .. I. broadly cordate, with a deep sinus, long-acuminate, 



branched. I. broadly cordate, with a deep sinus, long-acuminate, 

 opaque above, puberulous below ; petioles slender, concave 

 above. Root slender, often many feet long. h. 3ft Sikkim, 

 1837. (B. M 4877.) 



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

 calyx purple. 1. sub-orbicular, broadly cordate, obtuse, Hat, Sin. 

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

 slightly terete, angulate-sulcate. Stem 6ft. to 10ft. high, leafy. 

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



B. Emodi (Emodus). fl. whitish, in a fastigiate, dense panicle. 

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

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

 to 10ft Himalaya. 



B. nobile (noble).* fl. green, insignificant, in short, branched 

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

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

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

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

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

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



B. offlcinale (officinal).* fl. greenish, small, collected into dense 

 spikes. I. large, somewhat orbicular-reniform, five-nerved, and 

 cut into five short lobes at the margin ; lobes unequally incised. 

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

 A stately plant. (B. M. 6135 ; B. M. PL 213 ; R. H. 1874, 13.) 



B. palmatum (palmate-leaved), rl. in a leafy panicle. I. sub- 

 orbicular-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 

 cylindric. h. 5ft East and North Asia, 1763. (B. M. PL 214.) 



B. Bhaponticum (Rha ponticumi.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, fl. densely disposed in a leafy, fastigiate 

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

 nerved, glabrous above, puberulous below and on the veins; 

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

 fleshy, channelled above, and rounded at the edges, h. 4ft 1573. 

 (B. M. PL 215.) 



Fio. 364. RHEUM UNDULATUM. 



B undulatum (undulated), fl. densely disposed in a fastigiate 

 panicle, which is leafy below. I. ovate-cordate, undulated, five 

 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. 



