— Rumew.] LXIII. POLYGONACEA. 381 
flowers numerous, and when in fruit much crowded in a long narrow 
panicle, although the slender pedicels are really longer than the perianths. 
Inner segments of the fruiting perianth broadly ovate, more or less 
cordate, one of them bearing on the midrib an ovoid or oblong, coloured 
tubercle, whilst the others have the midrib only a little thickened, except 
in the southern varieties, where all three have often a tubercle. 
On roadsides, in ditches, pastures, and waste places, throughout Europe 
and Russian Asia, except the extreme north, and (probably naturalised) 
in many other parts of the globe. Abundant in Britain. Fl. summer. 
Specimens are occasionally found with the leaves rather broader and 
the perianth-segments very slightly toothed, R. conspersus, Hartm., 
showing an approach to R. obtuszfolius. These are by some believed to 
be hybrids between the two species, by others considered as a distinct 
species, FR. acutus, Linn. 
3. R. obtusifolius, Linn. (fig. 860). Broad D.—Stem 2 or 3 feet 
high, and but slightly branched, as in &. erispus, which it much re- 
sembles. It differs, however, in the broader leaves, the radical ones often 
8 or 9 inches, by 3 or 4, rounded at the top, and cordate at the base, 
the upper ones narrower and more pointed ; in the looser and more 
distinct whorls of flowers, and the less crowded panicles, although not 
‘near so spreading as in R. sanguineus; and especially in the inner 
segments of the perianth, which, although often broadly ovate, are 
never cordate, and are bordered below the middle by a few small teeth, 
usually ending ina fine point. As in R. crispus, one or all three segments 
have a small tubercle at the base. 
In the same situations and at least as widely spread and as common 
as R. crispus, with which and R. sanguineus it is usually mixed. Very 
abundant in Britain. Fl.swmmer. A variety of this species, A. sylvestris, 
Wallr., has nearly entire fruiting perianth segments. 
4, R. Hydrolapathum, Huds. (fig. 861). Water D.—Stem 3 to 5 
feet high, slightly branched. Leaves long, lanceolate or oblong, usually 
pointed, and flat or only very minutely crisped at the edges; the lower 
ones often 1 or 2 feet long, narrowed at the base into a long erect foot- 
stalk. Panicle long and rather dense, leafy at the base, the branches 
scarcely spreading. Inner perianth-segments ovate, not so broad as in 
R. crispus, and never cordate, entire or scarcely toothed, with a large 
oblong tubercle on all three, or rarely wanting on one of them. 
_ On the edges of streams and pools, and in watery ditches, in central 
and northern Europe and Russian Asia, but not an Arctic plant. Gene- 
rally dispersed over England, Ireland, and southern Scotland. FV. summer. 
A variety with the margins of the petioles raised and truncate or cordate 
inner perianth-segments has been distinguished under the name of R. 
maximus, Schreb., R. latifolia, Borrer. 
5. R. conglomeratus, Murr. (fig. 862). Clustered D.—Resembles in 
many respects R. sanguineus, of which it may be a tall, luxuriant variety, 
showing some approach to R. Hydrolapathum. Stem 2 or 3 feet high. 
Leaves often pointed, as in R&. Hydrolapathum, but more waved on the 
edges, and the lower ones often rounded or even cordate at the base. 
Panicle with spreading branches and distinct whorls, as in 2. sanguineus, 
but larger. Inner perianth-segments narrow-ovate, rather larger than 
in &. sanguimeus, and usually all equal, with an oblong tubercle upon | 
each. 
