Rumev.} LXIII. POLYGONACEJE. 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. obtustfolius. These are by some believed to 



\be hybrids between the two species, by others considered as a distinct 

 species, R. acutus, Linn. 

 3. B. obtusifolius, Linn. (fig. 860). Broad D. Stem 2 or 3 feet 

 high, and but slightly branched, as in R. crispus, 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 in a 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. summer. A variety of this species, R. sylvestris, 

 Wallr., has nearly entire fruiting perianth segments. 



4. B. Hydrolapathuxn, 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. Fl. 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. B. cong-lomeratus, 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 R. sanguineus, 

 but larger. Inner perianth-segments narrow-ovate, rather larger than 

 in R. tanguvnew, and usually air equal, with an oblong tubercle upon 

 each, 



