` 288 THE DICTIONARY 
OF GARDENING, 
Rhapis—continued. 
rted ; segments sub-plicate, ciliate-spinulose along the edges 
End keel “ot the plaits, indented-erose at the end; —— 
round-ancipital, naked, very obscurely denticulate. Stem about 
14ft. high, as thick as the thumb, sheathed by the reticulated, 
rsistent bases of the leaves. China and Japan, 1774. See Fig. 
E63. (B. M. 1374.) Syn. R. aspera. ? : 
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). l. cut into from seven to ten spreading 
segments; petioles unarmed. Similar in general aspect to 
R. flabelliformis. Japan, Syn. R. Sirotsik (of gardens). 
R. 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). Orv. 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 Bentham and Hooker, 
under Centaurea (which see for culture). 
R. scariosum (scarious). l.-heads purple; outer involucral 
scales all scarious, sub-entire or at length cut; inner ones 
narrower and very acuminate. July. /. glabrous above, cano- 
tomentose beneath ; lower ones petiolate, ovate or cordate, den- 
ticulate ; middle ones shortly petiolate, ovate-oblong ; uppermost 
ones sessile, orong, acuminate at both ends, scarcely toothed. 
h. 24ft. Switzerland, &c., 1640. (B. M. 1752, under name of Cen- 
taurea Rhapontica.) 
RHATANY ROOT. The 
triandra (which see). 
RHEA. A common name for Bæhmeria nivea. 
RHEEDIA (called after Hen. van Rheede, 1635- 
1691, a Dutchman residing at Malabar, author of 
“Hortus Malabaricus”). Orp. Guttiferæ. 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. 
ORD. Polygonee. 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. Rhaponticum and its varieties, and 
R. 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 
root of Krameria 
`i 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, 
see Rhubarb, 
Rheum—continued. 
R. acuminatum (taper-pointed). M. lurid-purple, bloody, or 
brownish-purple, {in, in diameter, spreading ; —— slightly 
branched. l. broadly cordate, with a deep sinus, long-acuminate, 
opaque above, puberulous below; petioles slender, concave 
stare. Root slender, often many feet long. h. 3ft. Sikkim, 
1837. (B. M 4877.) 
R. australe (Southern). M. in a long, racemiform, dense panicle ; 
calyx purple. J. sub-orbicular, broadly cordate, obtuse, tiat, Sin. 
to 4in. long, nearly 3in. broad; petioles 4in. long, slender, 
slightly terete, angulate-sulcate, Stem 6ft. to 10ft. high, leafy. 
Root fusiform, branched. Nepaul. (S. B. F. G. 269.) 
R. Emodi (Emodus). ji. whitish, in a fastigiate, dense panicle. 
l 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).* f. green, insignificant, in short, branched 
panicles; bracts delicate straw-colour, shining, semi-transparent, 
concave, imbricating, concealing the flowers, the upper ones with 
pink edges. l., 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.) 
R. officinale (officinal).* fl. greenish, small, collected into dense 
spikes. L 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.) 
R. — (palmate-leaved). ^. in a leafy panicle. J. sub- 
orbicular-cordate, — lobed, slightly scabrous or glabrous 
above, three to five-nerved; lobes ovate-oblong or lanceolate, 
acute, undivided, or incised-toothed or pinnatitid ; petioles nearl 
cylindric. A. 5ft. East and North Asia, 1763. (B. M. Pl, 214.) 
R. Rhaponticum (Rha ticum—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, fl. densely disposed in a leafy, fastigiate 
panicle. 1. sub-orbicular, profoundly cordate, undulated, five- 
nerved, glabrous above, puberulous below and on the veins; 
upper ones ovate or acuminate; footstalks long, thick, and 
—— rainy above, and rounded at the edges. h. 4ft. 1573. 
Fie. 364. RHEUM UNDULATUM. 
R. undulatum (undulated). jl. densely di 
r um í in a fastigiate 
panicle, which is leafy below. l. ovate-co te, — 
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. 
— Pea to 5ft. high, smooth, green. Siberia, &c., 1734. See 
