rhizoristic 
rhizoristic iri-/.o-ris'tik), a. [< Or. Ka, root, 
+ i'iii:aTuf, verbal adj. of opi^eiv, limit, define (see 
horizon, aorixt), + -/<.] In mutli., pertaining to 
the separation of roots of an equation. Rhizo- 
ristic series, a series of disconnected functions which 
serve to fix the number of real roots of a given function 
lying between any assigned limits. Sylvester. 
Rhizostoma (ri-zos'to-ma), n. [NL., < Gr. pifa, 
root, + ar&fia, mouth.] The typical genus of 
liliizostomiilie. It. jnilmo is an example. See 
cut under aculeph. 
Rhizostomata (ri-zo-sto'ma-ta), . pi. [NL., < 
Gr. pi'fa, root, + ar'6/ia(T-), "mouth.] An order 
of discomedusans, or suborder of Discomedusse, 
having the parts arranged in fours or multiples 
of four, and the single primitive mouth closed 
up and replaced by several secondary oral aper- 
tures, whence several long root-like processes or 
so-called polypites depend (whence the name), 
and provided with four subgenital pouches, dis- 
tinct (Tetrngamelige) or fused in one (Moin></n- 
ineliee). SUtostoma, Cassiopeia, Cephea, and 
Crambessa are leading genera. See cuts under 
acaleph and Diseophora. 
Ehizostomatidae (ri*zo-sto-mat'i-de), n. pi. 
[NL., < M*MftMM (-xtumai-) + -idee."] A fam- 
ily of acalephs; the root-mouthed jellyfishes: 
the emended form of Rhizostomid. 
ririzostomatous (ri-zo-stom'a-tus), a. [< Gr. 
pl{a, root, + OTO/M(T), moutli.] Having root- 
like processes depending from the mouth; spe- 
cifically, pertaining to the Rhizostomata, or hav- 
ing their characters. 
rhizostome (ri'zo-stom), n. A member of the 
Rhizostoutata. 
rhizostoruean (ri-zo-sto'me-an), n. [< rhizo- 
stonie + -.] Same as rhizostomatous. 
Rhizostomidae (ri-zo-stom'i-de), n. pi. [NL., 
< Rhizostoma + -idse.] A family of monoga- 
melian rhizostomatoug discomedusans, repre- 
sented by the genus Rhizostoma. They are huge 
jellyflshes, which may attain a diameter of 3 feet, possess 
powerful stinging-organs proportionate to their size, and 
are found chiefly in tropical seas. See cut under acaleph. 
rhizostomous (ri-zos'to-mus), a. Same as rhi- 
zostomatous. 
Rhizota (ri-zo'ta), n. pi. [NL., neut. pi. of rhi- 
zotita : see rhizoie.] An order of Rotifera, con- 
taining the rooted or fixed wheel-animalcules, 
as the families Flosculariidse and Melicertidse. 
C. T. Hudson, 1884. It is one of 4 orders, contrasting 
with Ploima, Bdettoyrada, and Scirtopoda. See cut under 
Floscularia. 
rhizotaxis (ri-zo-tak'sis), n. [NL., < Gr. pl^a, 
root, + rdfjf, order.] In hot., the arrangement 
or disposition of roots. Compare phyllotaxis. 
rhizotaxy (ri'zo-tak-si), n. Same as rhizo- 
taxis, 
rhizote (ri'zot), a. [< NL. rhizotus, < Gr. */f<j- 
r6f, rooted, < /><Co6v,.root, < pi^a, root.] Rooted, 
as a rotifer; of or pertaining to the Rhizota. 
RhizotrogUS (ri-zo-tro'gus), n. [NL. (Latreille. 
1825), < Gr. /w'fa, root, 4- rpuyeiv, gnaw, nibble, 
munch.] A genus of melolonthine beetles. R. 
solstitialis is a European species known as the 
midsummer chafer. 
rhizula (riz'u-la), ?i. [NL., dim. of Gr. pia, 
root: see root 1 .'] The root-like prothallium of 
mosses (prptonema) and of some other crypto- 
fams. [Disused.] 
odalose (ro'da-los), . [< Gr. poSov, rose (see 
rose 1 ), + a'Af (<i), salt, + -ose.~\ Red or cobalt 
vitriol ; cobalt sulphate. 
rhodanic (ro-dan'ik), . [< Gr. pofov, rose, + 
-an + -tc.j Noting an acid which produces a 
red color with persalts of iron . Rhodanic acid 
is also called stilphoeyanie acid. 
Rhodanthe (ro-dan'the), n. [NL. (Lindley, 
1834), < Gr. p6Sov, rose, + dv0of, flower.] A 
former genus of Compositse found in western 
Alistralia. The only species is It. Manglesii, of which 
there are several varieties, differing from each other mainly 
in the size and color of the flower-heads, which have the 
dry character of the flowers commonly called "everlast- 
ings." It is an annual, rising from 1 to 1J feet high, with 
an erect branching stem, oblong blunt entire stem-clasp- 
ing leaves of a glaucous green, and flower-heads, varying 
from deep rose to deep purple, supported on stalks ar- 
ranged in a corymbose manner. It is now made a section 
of Helipterum. 
Rhodeina (ro-de-i'na), n. pi. [NL., < Rhodem 
+ -/ a .] A group of cyprinoid fishes, typified 
by the genus Khodeus. They have a moderate anal 
(commencing under the dorsal), and the lateral line running 
midway between the upper and lower edges of the caudal 
peduncle. They are confined to Europe and Asia. 
rhodeoretin (ro-de-or'e-tin), n. [< Gr. poAeof, 
of roses (< puftov, rose), + ptrrivti, resin.] One 
of the elements of resin of jalap, identical with 
jalapin and convolvulin. It is hard, and insolu- 
ble in ether. 
5150 
rhodeoretinic (ro-de-or-o-tiii'ik). n. [< 
nri'lin + -'.] obtained from vhocleorotin. 
Rhodeoretinic acid, an acid produced l>y treating rho- 
deort'tin with alkalis. 
rhodes-WOod (rodz'wiid), . The wood of the 
West Indian tree Amijrix iMilxinuifrrn: so called 
from its resemblance to rhodium-wood, and 
used for a similar purpose. See rhodium-wood. 
Also called eandlcirixid. 
Rhodeus (ro'de-us). n. [NL. (Agassiz, 1836), 
< Gr. puAeof, of roses, < p&iov, rose : see rose*.] 
The typical genus of Rhodeitta. It. itmiirus (the 
liittcrling in German) is the typical species. 
Rhodian (ro'di-an). a. and H. ' [= F. Rhodien, < 
L. Rhodins, Rhodian, < Blind us, Rliodos, < Gr. 
'PoVfof, the isle of Rhodes.] I. a. Pertaining to 
Rhodes, an island of the Mediterranean, south- 
west of Asia Minor.- Rhodian laws, the earliest 
system of marine law known to history, said to have been 
compiled by the Rhodians after they had by their com- 
merce and naval victories obtained the sovereignty of the 
sea. Rhodian pottery. See pottery, and cut under am- 
phora. Rhodian school of sculpture, an important 
school of Hellenistic sculpture, of which the celebrated 
group known as the Laocojn Is the capital work. The ar- 
Kh.xli.in School of Sculpture. The Laocoon, in the Vatican. iThe 
existing incorrect restorations of arms, etc., are omitted.) 
lists of this school sought their Inspiration In the works 
of Lysippus. The intensity of expression attained in the 
Laocoon has never been surpassed, and its exaggerations 
are redeemed by its real power. The group, however, falls 
far short of the supreme excellence attributed to it by 
Pliny and by the art amateurs of the end of the eighteenth 
century. The Rhodian school is intimately connected 
with that of Pergamnm. 
II. n. A native or an inhabitant of Rhodes. 
rhoding (ro'ding), H. Naut., either of the brass 
boxes for the brake of a ship's pump. 
rhodiochlorid, rhodiochloride (ro"di-o-kl6'- 
rid, -rid or -rid), n. [< rhodium + ehlorid, chlo- 
ride.] In diem., a double chlorid of rhodium 
and the alkali metals. 
Rhodiola (ro-di'o-la), . [NL. (Linnaeus, 1737), 
< Gr. potiov, rose, + dim. -i-otu.] A former ge- 
nus of alpine plants belonging to the natural 
order Crasxulacex, now made a section of Se- 
dum (which see). 
Rhodites (ro-di'tez), n. [NL. (Hartig, 1840), < 
Gr. poii-nK , pertaining to a rose (applied to wine 
flavored with roses), < poAov, rose: see rose 1 .] 
A notable genus of gall-flies of the hymenopte- 
rous family Cyitipidee, having the hypopygium 
shaped like a plowshare, the marginal cell of 
the fore wings completely closed, and the claws 
of the hind tarsi entire. All of the species make 
galls on the rose. It. ros produces the mossy rose-gall, 
orbedegar. (See bed? gar.) K. mdicum produces root-galls. 
Seven species are known in North America, and five in 
Europe. 
rhodium (ro'di-um), n. [NL., < Gr. p6iiof, made 
of roses, rose-like, < p6fm', arose: see rose."} 
Chemical symbol, Rh ; atomic weight, 103 ( Jor- 
gensen). A metal discovered in the beginning 
of the nineteenth century by Wollaston, asso- 
ciated with palladium in the ore of platinum. 
Rhodium fuses in the flame of the oxyhydrogen blowpipe, 
but with greater difficulty than platinum. When fused 
it is grayish-white, resembling aluminium in luster and 
color, and has a specific gravity of 12.1. When pure it is 
almost insoluble in acids, but if in the state of an alloy it 
is dissolved by aqua regia. Of all the metals of the plat- 
inum group rhodium is the one most easily attacked by 
chlorin. Oil of rhodium. See oil. 
rhodium-gold (ro'di-um-gold), . A doubtful 
variety of native gold, said to contain a con- 
siderable amount of rhodium. 
rhodium-wood (ro'di-um-wud), 11. [NL. lifi- 
HIIIH rhodium, rosewood : see rhodium and rose- 
irood."] A sweet-scented wood from the root 
Rhododendron 
and stem of two shrubs, I'niirolnilii.t ni-i>)HiriiiK 
and ( '. Jtoridux, found in the Canaries, it has 
been an article of commerce, and from it was distilled an 
essential oil used in perfumery, liniments*, tt<:.. but now 
replaced by artificial compounds. The name is applied 
also, at least in the form nwdM^Mod, to the similar u.,n<l 
of Ainyrvt balmmtfera of the West Indies, etc., also r:ilk-d 
i-iiii'l[' a /. 
rhodizite (ro'di-zlt), . [So called because it 
colors the blowpipe-flame red ; < Gr. po6itti>, be 
like a rose (< puAov, rose), + -ite-.~] A rare bo- 
rate of aluminium and potassium, occurring in 
minute isometric crystals resembling boracite 
in form. It is known only from the vicinity of 
Ekaterinburg in the Urals. 
rhodochrome (ro'do-krom), n. [< Gr. 'p6am; 
rose, + xP"l^ a < color.] A mineral of a com- 
5>act or granular structure and reddish color. 
Ake the related crystallized mineral kummererite, it is 
classed as a chromiferous variety of the chlorite penninite. 
rhodochrosite (ro-do-kro'sit). n. [< Gr. /'lofor, 
rose, -I- xp"<"G, a coloring, + -ite 2 .] Native 
manganese protocarbonate, a mineral occur- 
ring in rhombohedral crystals, or massive with 
rhombohedral cleavage, usually of a delicate 
rose-red color. It is isomorphous with the other rhom- 
bohedral carbonates, calcite or calcium carbonate, siderite 
or iron carbonate, etc. Also called dialogite. 
Rhodocrinidae (ro-do-kriu'i-de), //. pi. [NL., 
< lihodocriinis + -idee.] A family of Crinoideii, 
typified by the genus Ilhodocriniis, having five 
basals, five parabasals orsubradials, and ten or 
twenty branched rays; the rose-encrinites. 
chiefly of the Carboniferous formation. 
rhodocrinite (ro-dok'ri-nit), . [< NL. Rho- 
docrhius + -ite'*.] An encrinite of the genus 
Rliodocrinux; a rose-encrinite. 
Rhodocrinus (ro-tlok'ri-nus), . [NL., < Gr. 
p6Aoi>, rose, + npivov, lily.] A genus of Paleo- 
zoic encrinites, or fossil crinoids, with a cy- 
lindric or slightly pentagonal column of many 
joints, perforated by a pentagonal alimentary 
canal; the rose-encrinites. 
Rhododendron (ro-do-den'dron), >/. [NL. 
(Linneeus, 1753), < Gr. po66Sev6pov, the olean- 
der, < pMav, rose, + ihfipov, tree.] 1. A large 
genus of shrubs of the order Ericacex and tribe 
Rhodoreae. It Is characterized by a broad, spreading, and 
oblique corolla, usually with five imbricating lobes ; eight 
to ten stamens, the anthers opening by pores ; and a five- 
to twenty-celled ovary with numerous ovules In many 
crowded rows, the seeds appendaged. There are about 
170 species, natives of the mountains of Europe, Asia, the 
Malay archipelago, and North America, most abundant 
in the Himalayas. They are commonly shrubs, less often 
trees, smooth, hairy, woolly, or scurfy, and often with 
whorled branches. They bear alternate entire leaves, 
most often crowded at the ends of the branches. Their 
handsome flowers are commonly borne in corymbs, and 
have conspicuous, more or less unequal, long, slender, 
and curving stamens, with long hairs clothing their base. 
e (Himalayas,. 
The fruit Is a woody pod, splitting septiciJally from the 
apex into valves, and filled with seeds like fine sawdust, 
each containing a cylindrical embryo and fleshy albumen. 
Most of the species, and all of those best known, produce 
tbeir new growths below the flowers, which form a termi- 
nal inflorescence destitute of leaves, and developed from 
a large scaly bud. The leaves in the typical species, form- 
ing the section Rhododendron proper, are evergreen anil 
coriaceous ; but they are deciduous in the sections Azalen 
and Tmna, which include the American species commonly 
known as azaleas, and produce leaves closely enchvlinu' 
the flowers, nr. in Tnwia, mixed with them. The flowers, 
nearly or quite 2 inches across, often reach in It. Auelf- 
landifp a breadth of fi inches. See pinkmrr-jlmt , , 
