eo 
RHEXIA. 
46 
sudden changes of weather in spring and autumn ; 
and is in some instances acute, and in others 
chronic,—in some continuous and accompanied 
with fever, and in others occasional or fitful and 
indicated chiefly by stiffness and lameness and 
expressions of pain. It may generally be pal- 
liated, but can rarely be cured. The remedies 
for it are shelter, warmth, aperients, diaphoretics, 
stimulating embrocations, and anodyne action 
both internally along with the aperients and ex- 
ternally along with the embrocations. 
Rheumatism in sheep is similar in at once 
causes, symptoms, and character, to rheumatism 
in cattle. Any sheep affected with it should be 
removed to a comfortable shed, and receive a 
warm aperient, and be rubbed over the affected 
part with opodeldoc or hartshorn liniment; and, 
if the disease become chronic, a seton should be 
inserted near the affected part. 
RHEXIA. A genus of ornamental, exotic 
plants, of the melastoma family. The Maryland 
species, 2. mariana, was introduced to Britain 
| from North America about 90 years ago; and is 
a handsome, hardy, purple-flowered, radical her- 
baceous perennial of about 9 inches in height ; 
and comprises a variety with pink - coloured 
flowers. Five or six other species have been 
introduced. 
RHINANTHUS. See Rartur (Yettow). 
RHIPSALIS. A genus of exotic plants, of the 
cactus order. Seven or eight species, mostly 
about a foot high, have been introduced to Bri- 
tish collections, and are propagable from cuttings. 
See the article Cactus. 
RHIZOBOLUS. See Burrer-Nur. 
RHIZOMA. See Orcuis. 
RHIZOPHORA. See Manerove. 
RHODANTHE. A recently discovered genus 
of ornamental plants, of the composite order. 
Captain Mangles’s species, 2. Manglesit, is one of 
the handsomest half-hardy annuals at present 
cultivated in British gardens. It is a native of 
Australia, and was introduced to Britain about 
16 years ago from the Swan River. It has a 
height of from 10 to 20 inches; and carries a 
profusion of flowers, with a blending of white 
and rose and yellow in their colours; and may 
be made to bloom from early spring till Novem- 
ber, A variety of it has semidouble flowers. 
RHODIOLA. A small genus of ornamental, 
hardy, perennial-rooted, herbaceous plants, of 
the crassulaceous order. The mountain species, 
f. rosea, grows wild in the fissures of mountain 
rocks and of sea-cliffs in various parts of Britain. 
Its root is thick and somewhat fleshy, and much 
divided at the crown; its herbage is smooth, 
glaucous, succulent, and about 8 inches high; 
and its flowers are numerous, and have a cymous 
arrangement, and are yellow in colour with blu- 
ish anthers, and bloom from May till July. The 
root, when recently dried, emits a fragrance simi- 
lar to that of rose-water; and it thence gives 
the whole plant the popular name of rose-root.— 
RHODODENDRON. 
The Siberian species, 2. sbirica, was introduced 
about 20 years ago, and is smaller than our na- 
tive species. 
RHODODENDRON. A genus of ornamental, 
exotic, chiefly evergreen shrubs, of the rhodora 
tribe. Nearly 30 species, varying in height from 
a few inches to about 30 feet, have been intro- 
duced to Britain; and a countless number of 
most magnificent hybrids have been raised by 
British cultivators. The genus is one of the 
most splendidly floral of all the ligneous ones in 
the world ; and now rivals the rose genus itself, 
in both prominence of position and brilliance of 
effect, in British shrubberies and gardens. 
The yellow-flowered or officinal rhododendron, 
f. chrysanthum, is a native of the mountainous 
parts of Siberia, and was introduced to Britain 
in 1796. It is one of the smallest of the rhodo- 
dendrons, and has commonly a height of only be- 
tween 5 and 10 inches. Its branches are spread- 
ing ; its bark is brown ; its leaves are few, terminal, 
oblong-ovate, smooth, and stiff, and are rugged 
and deep green above and ferruginous or glaucous 
below; its flowers grow in umbels at the ends of 
the branches, and are large and yellow, and have 
a monopetalous, five-segmented, outspread co- 
rolla, and bloom in June and July; and its cap- 
sules are ovate and somewhat angular, and con- 
tain numerous, grey, irregular, small, sawdust- 
like seeds. The leaves of this plant are used in 
medicine; and have an austere, astringent, bit- 
terish taste; and contain tannin, green wax, 
and various extractives; and yield their virtues | 
to water by either infusion or decoction; and | 
act upon the animal system stimulatingly, nar- 
cotically, and diaphoretically; and are admin- | 
istered to both men and cattle in cases of very 
bad or obstinate rheumatism ; but, when taken 
in over-dose, produce vomiting, purging, intoxi- 
cation and delirium. 
The rusty-leaved rhododendron, 2. ferrugin- 
eum, is a native of the Alps, Apennines, and | 
other mountains of Continental Europe, and was 
introduced to Britain about the middle of the 
last century. It has commonly a height of from 
14 to 3 feet. Its branches are numerous and 
irregular; its bark has a dark brown colour, 
tinged with purple; its leaves grow numerously 
on every twig, and occur in a pleasingly irregular 
order, and have a lanceolated outline, reflexed 
edges, and smooth surfaces, and are beautifully 
green above, and of an iron colour below, and 
little more than an inch in length ; and its flowers 
come out in round bunches at the ends of the 
branches, and have funnel-shaped, rose-coloured 
petals, and bloom from May till July. A variety 
of this species is more dwarfish than the normal _ 
plant, and has white flowers. 
The hairy-leaved rhododendron, 2. hirsutum, 
is anative of the mountains of Switzerland and 
Austria, and was introduced to Britain about the 
middle of the 17th century. It has commonly a 
height of from 15 to 30 inches. Its branches 
