Rhizoflagellata 
dages. These animalcules move by means of psendopo- 
dia, like ordinary rhizopods, but also have a flagellum or 
lla; the ingestive area is diffuse. In W. S. Kent's 
system of classification the order consists of the genera 
Maiftiyanwsba, Reptoinsniax, Rhizoinonag, and Podostowa. 
rhizoflagellate (ri-/.o-flaj'e-lat), . Of or per- 
taining to the Shizojtai/elliita. 
rhizogen (ri'zo-jeu), n. [< Gr. pia, root, + 
-; i iv/f , producing (see -gen }.] A parasitic plant 
growing on the roots of other plants; specifi- 
cally, a member of a division of plants (the 
class RhixanthfK) proposed by Lindley, com- 
posed of flowering plants of a fungoid habit, 
parasitic upon rootstocks and stems. It embraced 
the present orders Balanophorefe and Cytinacefe, now re- 
garded as belonging to the apetalous dicotyledons. The 
genus Raffltsia is an illustration. 
rhizogenic (ri-zo-jen'ik), <i. [As rhizoyrn + 
-ic.] In bot., root-producing: said of cells in 
the pericambium of a root, just in front of a 
xylem-ray of a fibrovascular bundle, which 
give origin to root-branches. 
rhizogenous (ri-zoj'e-nus), n. [As r\ 
-on*.] Same as rhizogenic. 
rhizoid (ri'zoid). a. and H. [< Gr. 
contr. p(fu<b?r, like a root, < pi,a, root, + tlfiot;, 
form.] I. a. In bot. and zool. , root-like ; resem- 
bling a root. 
II. H. In hot., a filamentous organ resembling 
a root, but of simple structure, found on com- 
pound thalli of all kinds, and on the stems of the 
Muscincee. Rhizoids are numerously produced, and their 
function is the attachment of the plant to the substratum. 
The older term was rhizina. See cut under prothallium. 
rhizoidal (ri'zoi-dal), a. [< rliizoid + -al.] In 
bot., rhizoid-like ; resembling or characteristic 
of a rhizoid. 
The rhizoidal tubes are segmented by only a few septa 
which lie far below the growing apex. 
Sachs, Botany (trans.), p. 282. 
rhizoideOUS (ri-zoi'de-us), a. [< rhizoid + 
-eons.] 1. In bot., like or resembling a rhizoid. 
2. Same as rliizoid. 
rhizoma (ri-zo'ma), M. ; pi. rliizomata (-ma-ta). 
[NL. : see rliizome.] A rhizome: used chiefly 
with reference to the rhizomes of medicinal 
plants. 
rhizomania (ii-zo-ma'ni-a), . [NL., < Gr. p/Cu, 
a root, + fiavia, madness.] In bot., an abnor- 
mal development of adventitious roots peculiar 
to many plants, as ivy, screw-pines, and figs, 
which send out roots from various parts, just 
as trees produce adventitious buds. In some 
plants rhizoraania is an indication that there is some de- 
fect in the true root, in consequence of which it cannot 
supply sufficient nourishment to the plant. In such cases 
rhizomania is an effort of nature to supply the deficiency. 
This is the case in common laurel, in which plant rhizoma- 
nia generally forebodes death. The phenomenon is also 
frequently seen in apple-trees, from the stems of which 
bundles of roots are sent out ; these, absorbing moisture 
and finally decaying, are a cause of canker on the tree. 
rhizome (rl'zom), . [= F. rliizome, < NL. rhi- 
zomu, < Gr. pi&fta, root, < ptovv, cause to take 
root, in pass, take root, < piC,a, root: see root 1 .] 
In bot., a stem 
of root-like ap- 
pearance, hori- 
zontal or ob- 
lique in po- 
sition, lyinj 
on the grouni 
or subterra- 
nean, bearing 
scales instead 
of leaves, and 
usually produ- 
cing from its 
apex a leafy 
shoot or scape. 
Rhizomes may be 
slender, with well- 
marked nodes, as 
in mints, couch- 
grass, etc. , or th ick- 
ened with stores 
of nutriment, as in 
species of iris, Sol- 
omon's-seal, etc. 
in the latter case 
producing at the apex an annual bud which furnishes the 
aerial shoot of the next season, and gradually dying at the 
old end. Rhizomes shade olf gradually into conns and 
bulbs on the one hand, and into tubers on the other. See 
these terms. Also rhizoma. See also cuts under arrow- 
root and mtmtHform. 
Rhizomonadidae (ri"zo-mo-nad'i-de), . pi. 
[NL., < lllii::<iiiioinix (-monad-) + -idee.] Afarn- 
ily of rhizoflagellate infusorians, typified by the 
genus RliizontiiiHiK. These animalcules are repent or 
sedentary, with a single anterior nagellum. The family 
includes xtoptontofuu and Maxtigainceba. 
Rhizomonas (ri-zom'o-nas), . [NL. (Kent. 
1880-1), < Gr. /7". root, + uowir, a unit: sec 
5180 
mound.] The typical genus of ltlii~inini>indid;i: 
The species are monadiform, unirtagellate, sedentary, with 
radiating digitiform pseudopodial prolongations. K. ver- 
rucosa is found in hay-infusions. 
rhizomorph (ri'zo-morf), M. [< NL. rM*offior- 
jilid.] In bot., a comprehensive term for 
certain subterranean mycelial growths asso- 
ciated with or preying upon the roots of the 
higher plants, especially trees, the cultivated 
vine, etc. They are produced by a considerable 
variety of fungi, as Agaricius melleiin, Deina- 
to/ilioi'a itecatrix, etc. 
Rhizomorpha (ri-zo-mor'fa), n. [NL., < Gr. 
p/C<j, root, + /top<t>i/, form.] A supposed genus 
of fungi, characterized by fibrous bundles of 
mycelial filaments, now known to belong to 
Agariciis melleits, Deiiiatophora necatrix, and 
other forms. 
rhizomorphoid (rl-zo-mor'foid), . [< rliiso- 
morph + -oid.] Rhizomorphous. 
rhizomorphous (ri-zo-mor'fus), ft. [< Gr. p/fa, 
root, + [iop<t'/, form.] 1. Boot-like in form. 
2. In zool., same as rhizoid. 
Rhizomys (ri'zo-mis), . [NL. (J. E. Gray, 
1830), < Gr. />i'C<z,'root, + /^uf, a mouse.] A nota- 
ble genus of mole-rats of the family Spalaciilee, 
baring the eyes open, though very small, ears 
naked and very short, thumb rudimentary, tail 
Forms of Rhizome. 
, Polygonatum giganteum (Solomon's- 
l); 2, Arisscma triphvllnm (Indian tur- 
Bamboo-rat (Rhizotnys badius}. 
short and partially haired, and general form ro- 
bust. The upper incisors arch forward, and there is no 
premolar ; the upper molars have one deep internal and two 
or more external enamel-folds ; the lower molars reverse 
this pattern. There are several Asiatic and African spe- 
cies, as the bay bamboo-rat of Asia, R. baditts, which is of 
large size and very destructive to the bamboo, on the roots 
of which it feeds. 
rhizonychial (ri-zo-nik'i-al), a. [< rkftottyoU- 
HIH + -al.] Rooting or giving root to a nail or 
claw ; of or pertaining to a rhizonychium. 
rhizonychium (ri-zo-nik'i-um), .; pi. rhizo- 
nycliia (-a). [NL.,< Gr./'Ca, root, + ovv$(bwx-), 
a claw.] A claw-joint ; the ungual or last pha- 
lanx of a digit: that phalanx which bears a 
claw. 
Rhizophaga (ri-zof'a-ga), n. pi. [NL., neut. 
pi. of rhizophagus : see rhizopkagom.] One of 
five sections in Owen's classification of marsu- 
pials, including those which feed on roots. 
The wombat is a characteristic example. 
rhizophagan (ri-zof a-gan), . and n. I. a. 
Same as rhizopliagonx. 
II. n. A member of the Rhizophagti. 
rhizophagous (ri-zof'a-gus), a. [< NL. rliizo- 
pliayus, < Gr. /><o0d;of, eating roots ('pii^o^ayelv, 
eat roots), < />/, root, + ^a-,'tlv, eat.] Root- 
eating; habitually feeding on roots; specifi- 
cally, of or pertaining to the Uliizopltaga. 
All Poor-Slaves are Rhizophayous (or Root-eaters). 
Carlyle, Sartor Eesartus, iii. 10. 
Rhizophora (ri-zof'o-ra), n. [NL. (Linnseus, 
1737), named with ref. to the aerial roots ; neut. 
pi. of rliizopkoi'HS : see rhizopJiorous.] A ge- 
nus of polypetalous trees, the mangroves, type 
of the order Rltizo/thoracese, and of the tribe ti!- 
eopliorex. It is characterized by a four-parted calyx, sur- 
rounded with a cupule or involucre of partly united bract- 
lets, by its four petals and eight to twelve elongated and 
nearly sessile anthers, which are at first many-celled, and 
by a partly inferior ovary which is prolonged above into 
a fleshy cone and bears two pendulous ovules in each of 
its two cells. There are 2 (or, as some regard them. 5) 
species, frequent on muddy or coral shores in the tropics, 
there forming dense and almost impassable jungles known 
as mangrove-swamps. They are trees with thick cylin- 
drical and scarred branchlets, bearing opposite thick and 
smooth coriaceous leaves, which are ovate or elliptical and 
entire. Their large rigid flowers are borne in axillary 
clusters, followed by a nut-like one-seeded fruit. The 
seed is remarkable for germinating while yet in the long- 
persistent fruit. It contains a large embryo with a very 
long club-shaped radii-lc, which soun pierces the point of 
the hard pericarp and lengthens till it reaches the mud, 
or becomes a foot long before falling. The mangrove is 
also remarkable for spreading by aerial roots. The ordi- 
nary species is II. ntucruixita, which reaches to semitropi- 
cal Florida, the delta of the Mississippi, nnd Texas. See 
mangrove. 1. 
rhizopodous 
Rhizophoraceae (ri"zo-fo-ra'se-e), . pi. [NL. 
(Lindley, 1845), <l{hizopliora + -aceae.] An order 
of dicotyledonous trees and shrubs of the cohort 
M//rttilex and series t'alyciflorse; the mangrove 
family. It is characterized by a two- to six-celled ovary 
with its ovules pendulous from the apex of the cell, and by 
a valvate calyx, and two, three, or four times as many sta- 
mensas petals. It includesabout 50 species in il'genera and 
3 tribes, all tropical, and most of them forming dense and 
malarious jungles about river-mouths and along shores. 
They are usually extremely smooth, with round and nodose 
branchlets, and opposite thick and rigid leaves, which arc 
commonly entire and have elongated and very caducous in- 
trapetiolar stipules. They bear axillary cymes, panicles, 
spikes, or racemes of rather inconspicuous flowers. 
rhizophore (ri'zo-for), . [< NL. rhi^ii/ilmniii/. 
neut. of rMfOfkorva, root-bearing: see rlii- 
:oplioroi(S.~\ In bot., a structure, developed in 
certain species of the genus SelagineUa, which 
bears the true roots. It has the external appear 
ance of a root, but has no root cap, and the true roots are 
produced from its interior when it deliquesces into a 
homogeneous mucilage. 
Rhizophorese (ri-zo-fo're-e), . pi. [NL. (R. 
Brown, 1814), < Rhizophora + -ex.] A tribe of 
plants of the order Bliizoiilioracex. It is character- 
ized by extremely smooth opposite entire and stipulate 
leaves, and by an inferior ovary with a single style and an 
embryo without albumen. It includes about 17 species, all 
tropical maritime trees, belonging to 4 genera, of which 
Ithizophora, the mangrove, is the type. 
rhizophorous (ri-zof'o-rus), a. [< NL. i7ii.ro- 
phorus, < MGr. pioQ6pos, root-bearing, < Gr.p/Co, 
root, + -</>opof, < ifiipctv = E. bear 1 .] In bot., 
root-bearing; specifically, of or pertaining to 
the natural order Rttizophoraccx. 
rhizophydial (ri-zo-fid'i-al), a. [< Kltlzi>lj- 
dium + -al.] In bot., belonging to or charac- 
teristic of the genus Bhizopliydivni. 
Rhizophydium (ri-zo-fid'i-um), . [NL. 
(Schenk), supposed to stand for *Bliizopltidiiin>, 
alluding to the deficiency of roots ; irreg. < Gr. 
/Wfa, root, + 0e5<ir, sparing.] A small genus of 
unicellular zygomycetous fungi, of the suborder 
Cladocliytrieee, parasitic on certain of the larger 
algffi. The parasitic cells enter the cells of the host plant 
at a very early stage of-their existence, and gradually de- 
velop at the expense of the protoplasmic contents of the 
latter. R. IHcksonii is parasitic on species of Ectocarputt. 
rhizopod (ri'zo-pod), a. and . [< NL. "rhieopus 
(-pod-) (as a noun, in def. 2, rhizopodi-um), < Gr. 
/fa, root, + Troi'p (7ro(5-) = E. foot.] I. a. Pro- 
vided with pseudopods, as an animalcule: hav- 
ing processes of sarcode, as if roots, by means 
of which the animalcule is attached or moves ; 
root-footed ; specifically, of or pertaining to the 
Rliizopoda, in any sense. Also rliizopodotis. 
II. n. 1. A member of the Khizopoda, in any 
sense. 2. In hot., same as rhizopodinm. 
Rhizopoda (ri-zop'o-da), n. i>l. [NL. : see rlii- 
zopod.] If. In Dujardin's system of classifi- 
cation (1841), the third family of "diversiform 
infusorians without visible locomotory appen- 
dages" that is, without permanent appen- 
dages, as cilia or flagella . This is the original mean- 
ing of the word, since much extended. Dujardin included 
in his Rhizopoda the 8 genera Arcella, Dfjnv'fia, Trinema, 
Euglypha, Gromia. Uiliola, Crislellaria, and Vcrticella. 
2. The lowest class of 1'rotozoa, composed of 
simple or multiple animalcules without definite 
or permanent distinction of external parts, and 
provided with diversiform temporary or perma- 
nent pseudopodial prolongations of the body- 
substance, by means of which locomotion, fixa- 
tion, and ingestion are effected. There is no mouth 
or special ingestive area; the sarcode may be distinguish- 
able into an outer ectoplasm and an inner endoplasm ; 
a nucleus and nucleolus (endoplast and endoplastule) 
may be present ; and most of these animalcules secrete a 
shell or test, often of great beauty and complexity. The 
rhizopods are minute, usually microscopic organisms, 
some or other forms of which abound in both salt and 
fresh waters. The characteristic pseudopodia are highly 
diverse in form, and constantly change, but occur in two 
principal forms, coarse lobate or digitate processes and 
fine slender rays, both of which may run together or in- 
terlace. The valuation and limitation of the llhizopoda 
have varied with different authors. A normal amceboid 
protozoan is a characteristic exampleof this class. Other 
forms included under RMzoptida are the so-called moners 
of the order Monera ; the Foraminifera, with a calcareous 
shell; and the Radiolaria, with a siliciuus shell. By com- 
mon consent the sponges, which have been classed with 
Rhizopoda, are now excluded, even by those who still con- 
sider these organisms as protozoans. See cuts under 
Amoeba, Foramina/era, and Radiolaria. 
rhizopodal (ri-zop'o-dal), a. [< rliizoimd + -/.] 
Same as rJiizopoil. II'. B. Ctirpenter, Micros., 
xii. $ 474. 
rhizopodan (ri-zop'o-dan), a. and w. [< )7i/^o- 
jiod + -tin.] Same as rhi-iipod. 
rhizopodium (ri-zo-po'di-um). n. [NL.: see 
rliizopml.] In bot., the mycelium ot fungi. 
Also rJiizopod. 
rhizopodous (ri-zop'6-dus), . [< rlii~<>)>i><i + 
-mi.s-.j Same as rhhnjind. 
