RHUS. 
a right-angled-triangle, whose two other sides are the ship’s 
way or distance run in longitude and latitude. Now, the 
latitude is usually had by observation, and the angle of the 
rhumb, with one or other of the two sides, by the compass. 
All, therefore, that is required by calculation in sailing, 
is the value of the length of the rumb-line for the distance 
run. 
RHUME, a small river of Hanover, in the principality of 
Calenberg, which falls into the Leine, near Nordheim. 
RHUS, [of Pliny. Pov? of Dioscorides.] in botany, a 
genus of the class pentandria, order trigynia, natural order of 
dumosae, terebintaceae, (Juss.) Generic Character.—Ca¬ 
lyx : perianth five-parted, inferior, erect, permanent. Co¬ 
rolla : petals five, ovate, from upright spreading. Stamina : 
filaments five, very short. Anthers small, shorter than the 
corolla. Pistils: germ superior, roundish, the size of the co¬ 
rolla ; styles scarcely any ; stigmas three, cordate, small. 
Pericarp: berry roundish, one-celled. Seed one, roundish, 
bony. Essential Character. —Calyx: five-parted. Petals 
five. Berry one-seeded. With pinnate leaves. 
1 . Rhus coriaria, or elm-leaved sumach.—The common or 
elm-leaved sumach has a strong woody stem, dividing into 
many irregular branches, and rises to the height of eight or 
ten feet. The leaves are composed of seven or eight pairs of 
leaflets terminated by an odd one. The flowers grow in 
loose panicles at the end of the branches.—It grows naturally 
in Italy, Spain, the south of France, and the Levant. It is 
used instead of oak bark for tanning leather, and it is said 
that Turkey leather is all tanned with this shrub. 
2. Rhus typhinum, or Virginian sumach.—This has a 
woody stem, from which are sent out many irregular branch¬ 
es, generally crooked and deformed. The young branches 
are covered with a soft velvet-like down, resembling greatly 
that of a young stag’s horn both in colour and texture, whence 
it has vulgarly the name of the stag’s-hom tree. The flowers 
are produced in close tufts at the end of the branches in July; 
and are followed by seeds, inclosed in purple woolly, succu¬ 
lent covers, so that the bunches are of, a beautiful purple co¬ 
lour in Autumn: the leaves also then change first to a pur¬ 
plish, and before they fall, to a feuillemort colour. This 
shrub, as well as the preceding, is used for tanning leather; 
and the roots are prescribed in medicine, where it grows na¬ 
turally ; that is in almost every part of North America. 
3. Rhus Javanicum, or Java sumach.—This is a large tree 
with spreading branches. Leaves unequally pinnate, with 
from five to seven pairs of leaflets. Flowers small, in a com¬ 
pound, tomentose, terminating panicle. Corolla white, bell¬ 
shaped, longer than the calyx.—-Native of China and Japan, 
where it flowers in September. 
4. Rhus glabrum, or scarlet sumach.—This is not so high 
as the common Virginian sumach, the branches are much 
more spreading and smooth, the leaflets are wider and less 
serrate.—Native of North America, in woods, high glades, 
and old corn-fields. It is like a weed in some parts of the 
country, and if a field be left a few years uncultivated, this 
shrub overruns it. 
5. Rhus elegans, or Carolina sumach.—This rises com¬ 
monly to the height of seven or eight feet, and divides into 
many irregular branches, which are smooth, of a purple co¬ 
lour. The leaves have seven or eight pairs of lobes, not al¬ 
ways exactly opposite; they are three or four inches long, and 
almost an inch broad in the middle; above they are of a dark 
green, underneath hoary but smooth. Flowers of a bright 
red colour, in very close, thick, large, panicles; appearing in 
July and August, and continuing till autumn.-—Native of 
South Carolina. 
6 . Rhus vernix, or varnish sumach.—Trunk straight. 
Leaflets four or five pairs, sometimes more, the upper surface 
green and smooth, the lower paler and pubescent, entire 
about the edge or sometimes slightly sinuate, with oblique 
superficial veins, and the midrib inclining to the inner 
side, except in the odd leaflet, which it divides into equal 
parts. Petioles oblong, purple. From the base of these 
come out the peduncles, which are green, and bear many 
67 
flowers in a racemed spike; these are small and herbaceous. 
Fruit a juiceless drupe, slightly compressed: rind thick, on 
the outside highly polished and shining, within of a fib¬ 
rous and fungous substance, or at first pulpy but not succu¬ 
lent, becoming dry when ripe, with a fibrous net, in which 
the stone lies; shell bony, transversely elliptic, obscurely 
wrinkled, thick ish, of a pale testaceous colour without. Seed 
obliquely elliptic, pale, fastened by an umbilical chord, which 
ascends from the bottom of the shell to the top of the seed. 
According to Cutler, the blossoms are whitish; the panicles 
open; the fruit yellowish, small and pear-shaped. It is com¬ 
mon in swamps in North America, whence it is called 
swamp-sumach, and flowers in June. 
Kalin gives this account of the American poison-tree or 
swamp-sumach. An incision being made, a whitish-yellow 
juice, which has a nauseous smell, comes out between the 
bark and the wood: it is noxious to some persons, but does 
not in the least affect others. On himself it had no effect, 
except once, in a hot day, when being in some perspiration, 
he cut a branch, and carried it in his hand for half an hour, 
smelling at it now and then. It produced a violent itching 
in his eye-lids and the parts thereabouts, and during a week, 
his eyes were very red, and his eye-lids very stiff: but the 
disorder went off by washing the parts in very cold water. 
Thunberg affirms that the best Japan varnish is prepared 
from the Rhus vernix, which grows in great abundance in 
many parts of that country, and is likewise cultivated in se¬ 
veral places, on account of the great advantage derived from 
it. This varnish, which oozes out of the tree on its being 
wounded, is procured from stems that are three years old, and 
is received in some proper vessel. 
7. Rhus succedaneum, or red lac sumach.—This is cer¬ 
tainly distinct from the preceding, to which it is allied, but 
differs from it particularly in the size of the leaves. In this 
species these are somewhat rigid, shining on both sides, very 
seldom equal on both margins. In Rhus vernix, the leaves 
are of an opaque green. The fruit in this species is the size 
of a cherry, and not white; in that it is only the size of a pea, 
and white.—Native of Japan and China. Introduced in 
1773 by John Blake, Esq. It flowers in June. 
Osbeck informs us that the Chinese call the Rhus Javani¬ 
cum Tay-sha, and the Rhus Chinense, by which he means 
this species, Mon/chi. 
The true Chinese varnish or lacker-tree, is named in China 
Sat Shu, and not UTong Shu. In collecting the varnish, 
they make an incision in the bark, and insert a tube for the 
juice to run into a little pot; which is taken in every morn¬ 
ing before sun-rise. The juice blisters the skin. 
8 . Rhus semialatum, or half-winged sumach.—Leaves pin¬ 
nate serrate, petioles on the outmost internodes membrana¬ 
ceous. 9. Rhus copallinum, or lentiscus-leaved sumach.— 
Leaves pinnate quite entire, petiole membranaceous jointed. 
10. Rhus alatum, or winged sumach.—Leaves pinnate, leaf¬ 
lets ovate serrate at the end, petioles on all the intemodes 
winged. 11. Rhus pauciflorum, or few-flowered sumach.— 
Leaves pinnate, leaflets alternate, decurrent, wedge-shaped, 
serrate at the end, panicle sessile, few-flowered. 
12. Rhus metopium, or the hog gum-tree.—This tree sel¬ 
dom rises to more than twenty-five or thirty-five feet, and is 
very spreading towards the top. It is surrounded with round 
pinnate leaves, which have seldom above five leaflets on every 
rib ; and the flowers, which grow in clusters, are succeeded 
by so many reddish succulent capsules. It yields a great 
quantity of a gummy resin, which, when pure, is of a yel¬ 
low colour, and after a short time, acquires a hard brittle 
consistence.—Native of America. 
13. Rhus digitatum, or finger-leaved sumach. 14. Rhus 
pentaphyllum, or five-leaved sumach.—With ternate leaves. 
15. Rhus cirrhiflorum.—Scandent, leaflets quite entire, 
smooth. 16. Rhus tridentatum.—Scandent, leaflets hoary 
serrate, serratures three to five.—Natives of the Cape. 
17. Rhus radicans, rooting poison-oak, or sumach.—This 
has a low shrubby stalk, which seldom rises more than three 
feet high, sending out shoots near the bottom, which trail 
upon 
