65
��#ncjtital %xiuUs.
��ON THE PORMS AND DISTRIBUTION OVER THE WORLD OF THE BATRACHIUM SECTION OF RANUNCULUS.
By W. p. Hiern, M.A.
{Continued from p. 49.) (Plate CXIV.)
Ranunculus hydrocharis, Spenner, Fl. Prib. iv. 1007 (1829),
Ranunculoides, Vaillant, Bot. Par. p. 170 (1727). Ranunculus, sect. 1, Grammatocakpi, Biria, Hist. Reuonc. p. 32 (1811). Ranun- culus, sect. Batrachium, De Caiid. Regn. Veg. Syst. Nat. vol. i. p. 233 (1818). Batrachium, S. F. Gray, Nat. Arr. Brit. PL vol. ii. p. 720 (1821). Ranunculus, trib. Leucobatrachinm, sect. Hydrelis, Webb and Berth. Hist. Nat. Fl. Canar.vol. iii. pt. 2. sect. i. 6 (ISIO). ItauHucidus aquatiUs, Hook. f. et T. Thorns. Fl. Ind. vol. i. p. 28 (1855). Rannncnlits aqnaticus, Benth. Haudb. Br. Fl. ed. 1. p. 59 (185 8). Beuthara and. Hooker f. in ' Genera Plantarum,' vol. i. p. 6 (1862), state that this group, which has been considered as a distinct genus by some authors, includes a few species which probably ought to be reduced to one or two. Seringe in Mel. Bot. vol. ii. n. 4. p. 49 (1826) expressed his suspicion that there was but one species, and in his printed notes he has spoken more positively. Many of the ante-Limieaa European botanists recognized five distinct species.
Scattered over most parts of the world, growing in ponds, pits, ditches, streams, rivers and even seas, occasionally also at tlie edges of watery places and on mud ; mentioned as occurring in Colombia, S. America (see Mosquera, Corapend. Geograf. General. Colomb. 1866); but not included in the ' Flora of New Zealand ' of Dr. J. D. Hooker, nor in the ' Flora Ant- arctica ' of the same author, nor in the 'Flora Brasiliensis ' of Martins and Endlicher. Generally perennial, but occasionally annual. The fol- lowing groups and forms give the principal modifications of this poly- morphous species, but by no means exhaust its variability ; numerous intermediate states exist that cannot be completely identified with any of them : — </ R. hederaceus, L. Sp. PI. p. 781 (1753). R. hedercpfoUus, Salisb.
Prodr. Stirp. p. 373 (1796). Batrachium hederaceum, S. F. Gray, Nat.
Arr. Brit. PI. vol. ii. p. 721(1821). Batrachium, sect. Platyphyl-
LE.E, Dumort. Monogr. (1863). R. JiydrocJiaris, B. homoiophyllus, a.
hederaceus, Spenn. Fl. Frib. (1829). — Fig. — Fl. Dan. t. 321. Eng. Bot.
t. 2003. Sturm, Deutschl. Fl. p. 67. Rchb. Fl. Germ. 3. 2. Godr.
Essai, f. 1. Cosson and Germ. Atl. t. 1. f. 1, 2. Forms 1-7.
Common in Europe and North Africa ; occurs also in North America,
but not included in either Asa Gray's or Chapman's American Floras.
According to Schlechtendal it reaches Siberia and the Aleutian Isles.
This group cannot be absolutely separated from R. aquatiUs, L. ; though
in most cases it is sufficiently different. 1\ms Batrachium pel tatum,
isophyllum, Fr., and R. trinacrius, E, and A. Huet du Pavilion of the
latter group have no submersed leaves, or scarcely any, while Lobbii of
VOL. IX. [mAUCII 1, 1871.] F
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