REVISION OF RUMEX. 93 



deltoid or almost 3-lobed sharply toothed valves. It is 

 found also in other localities, and may usually be recognized 

 from a distance owing to the ragged appearance of the 

 inflorescence, only a small percentage of the flowers en- 

 larging (and fewer yet developing seed), so that the fruit- 

 ing valves appear abnormally large by contrast, while they 

 persist after the falling of the undeveloped flowers. 



So far as I can determine, this is R. acutus, L. = R. 

 pratensis, M. & K., which occurs throughout northern Eu- 

 rope (where it is often sterile), and is now generally admitted 

 to be a hybrid of the two species named. Belated but dis- 

 tinguishable hybrids are the Scandinavian R. conspersus, 

 Hornem. , R.platyphyllos, F. W. Aresch. , and R. propinquus, 

 J. E. Areschoug, on all of which see F. W. Areschoug 

 in Ofvers. K. Vet. Akad. Forh., 1862, 57-76 with plate 3. 

 American specimens have been examined from numerous 

 localities in and about St. Louis, Mo., Belleville, 111., North 

 Manitou Isl., L. Mich. (Mrs. Wislizenus), Ithaca, N. Y. 

 (Dudley, 1883, 114), Amherst, Mass. (Jesup, 1871), and 

 Washington, D. C. ( Ward, 1884). Plate 31. 



19. K. PERSIC ARIOIDES, L. Annual, a span to mostly 

 a couple of feet high, slender to thick but soft stemmed," 

 the larger plants branching from the base and often pros- 

 trate and rooting at the nodes, soon fistulous, subglabrous 

 to mostly papillate-villous ; leaves pale green, usually un- 

 dulate, the largest 3x18 cm., lanceolate, mostly acute, the 

 base commonly truncate, rounded or subcordate, papillate 

 beneath on the principal veins ; panicles leafy, axillary and 

 terminal, the very dense whorls crowded to quite remote; 

 pedicels capillary, scarcely twice as long as the fruit, tumidly 

 jointed at base; valves 1.5x2.5 mm., equalled in length by 

 the 2 or 3 bristle-form teeth on each side, the apex acutely 

 produced but not bristle tipped; callosities 3, subequal, 

 smooth, .3 to .4 mm. broad, compressed from the sides, 

 nearly as long as the body of the valve; achene .6x1.2 

 mm. Sp. i. (1753), 335. R. maritimus of most recent 



