380 THE POLYGONUM FAMILY. [ Rumen. 
A considerable genus, spread over the greater part of the world, very 
readily distinguished from the rest of the Order, but the species vary so 
much in appearance that it is often very difficult to fix their real limits. 
They can also seldom be determined without the fruiting perianth, from 
which most of the characters are taken. They may be readily distributed 
into two distinct sections, Rumex proper and Acetosa, 
Leaves never hastate at the base (though often cordate, with 
ie auricles), Flowers mostly hermaphrodite (Rvu- 
MEX). 
Inner perianth-segments entire, or with one or two scarcely 
perceptibe teeth. 
Segments broadly ovate, more or less cordate. Panicle 
narrow and crowded when in fruit. 
No tubercle on any of the perianth-segments ; :> aquaticus, 
A tubercle on one at least of the perianth-segments . 2. FR, crispus. 
Segments ovate, not cordate. 
Tall water-plant. Lower leaves above a foot long. 
Panicle erect. A tubercle on all three perianth- 
segments . p . «. »« « « & Bt, Hydrelapathum. 
Plant seldom above 3 feet. Lower leaves nota foot. 
Panicle very spreading. Perianths small. . 
A tubercle on all three Der anth sae ° ° . 5. B. conglomeratus, 
A tubercle on one segment only . 6. B. sanguineus. 
Inner perianth-segments toothed on the edge, one at least of the 
teeth ending in a fine point, 
Panicle erect. Pedicels longer than the perianth . 3. BR. obtusifolius. 
Panicle very spreading. Pedicels shorter than the fruit- 
ing perianth. 
Leaves chiefly radical. Pedicels thickened. Teeth of 
the perianth-segments stiffand short . 7. BR. pulcher. 
Panicle leafy. Perianths densely clustered with ‘long 
fine teeth to the segments. 3 8. R. maritimus. 
Leaves, at least the lower ones, hastate (with acute auricles). 
Flowers mostly unisexual (SorRz1xs). 
Leaves oblong or broadly lanceolate. Inner segments of 
the fruiting perianth enlarged and orbicular ; 9. HB. Acetosa. 
Leaves narrow-lanceolate or linear. Inner segments of the 
fruiting perianth not enlarged 3 4 ° : . 10. R. Acetosella, 
Besides the above, #&. alpinus, from the mountains of continental 
Kurope, formerly cultivated for its root, a very broad-leaved species of 
true Rumex, with entire, grainless perianth-segments, and the French 
Sorrel (R&. scutatus), also a common plant in Continental mountains, 
sometimes cultivated as a Sorrel, have both been met with occasionally 
in Scotland or northern England, near the gardens from which they 
had escaped, but neither of them appears to be really established in 
Britain. 
1, R. aquaticus, Linn. (fig. 856). Grainless Dock.—Closely re- 
sembles the larger and denser-flowered forms of &. crispus, of which it 
may be a luxuriant variety. The leaves are usually not so much crisped, 
sometimes nearly flat, and often 9 or 10 inches long and full 3 inches 
broad; the panicle long and much crowded; but the chief. difference is in 
the inner segments of the fruiting perianth, which are of the same shape, 
but have no tubercle, although a slight thickening of the midrib may be 
sometimes observed. 
In rather rich and moist situations, in northern and Arctic Europe, Asia, 
and America, and in the mountains of central Europe. In Britain, confined 
to Scotland and the north of England. 7. summer. 
