148 
RANUNCULUS 
PI. 556(1753) partim (cf. Williams in Journ. Bot. xlvi, 11 (1908)); R. aquatilis Weber in Wiggers FI. Holsat. 42 
(1780); R. divaricatus Schrank Baier. FI. ii, 104 (1789) 1 ; R. aquatilis var. diffusus Withering Arr. Brit. PI. ed. 3, 
ii, 507 (1796) ; R. pantothrix var. capillaceus DC. Syst. Nat. i, 235 (1818); Batrachium pantothrix Gray Nat. Arr. 
ii, 722 (1821) excl. syn. Brotero. 
Perennial. Shoot usually elongate, often rather hairy above. Submerged leaves often rather short, 
up to about 6 — 7 cm. long; sheaths usually auricled, adnate below; petioles usually short or absent; 
primary leaf-divisions usually stalked ; ultimate divisions rather short, linear or capillary, spreading, 
collapsing or not when taken out of the water. Pedicels shorter than in R. aquatilis , not tapering, 
usually about as long as or a little shorter than the leaves. Receptacle hairy, subglobose or a little 
longer than broad. Flowers small, 1 — 2 cm. or rather more in diameter; late April to June. Petals not 
or scarcely contiguous, about 1*5 — 2’o times as long as the sepals. Stamens about 10 — 15, longer 
than the ovaries. Stigma broad. Achenes up to about 30, hairy, beaked. 
Although, in dried examples, var. rigidus and var. droueti are often difficult to determine, and although we frequently 
meet in nature with plants intermediate between the two, yet in many of the ditches of the fenny parts of Cambridgeshire 
we find the two plants growing side by side and remaining distinct : in such places, we have noticed that var. droueti comes 
into flower two to four weeks earlier than var. rigidus. 
In the fresh state, the two varieties are most readily distinguished by the stiff leaves of var. rigidus , which do not 
collapse when taken out of the water, and the flaccid leaves of var. droueti , which readily collapse under the same conditions. 
It has been suggested that this character of the leaf-segments is due to the mineral-content of the water in which the plants 
grow : it is said that var. rigidus prefers calcareous water, and var. droueti non-calcareous water, “ so that in the former the 
leaf-segments remain more or less divergent, and in the latter they collapse together, when the plant is withdrawn from the 
water” (Williams op. cit. p. 48). We are unable to endorse this suggestion, as both varieties are locally abundant in the 
calcareous waters of Cambridgeshire, and often occur together in the same ditch. We suspect some structural difference 
is the cause of the rigidity and the flaccidity of the leaf-segments of the respective varieties. 
(a) R. trichophyllus var. tripartitus Koch Syn. 11 (1835); R. petiveri var. major Koch Syn. ed. 2, 14 
(1843); P- radians Revel in Act. Soc. Linn. Bordeaux xix, 120, fig. 1 (1853); R. heterophyllus Babington in Ann. 
Nat. Hist. ser. 2, xvi, 393 (1855) et auct. angl., pro max. parte; R. trichophyllus race radians Rouy et Foucaud 
FI. France i, 67 (1893); Batrachium diversifolium Corbiere 2 Ft. Normand. 20 (1893). 
leones : — Sturm Deutschl. FI. t. 82. 2, as R. petiveri. 
In our note in the Journal of Botany for 1914, we referred (pp. 116 — 117) the above figure to R. obtusiflorus : 
we now think it is better placed as above, on account of its hairy achenes. 
Camb. Brit. FI. iii. Plate 156. (a) Flowering branch, (b) Submerged leaf. ( c ) Receptacle and pedicel. 
(d) Flower, (e) Petals, (f) Achenes (two enlarged). Huntingdonshire (E. W. H.). Plate 157. (a) Flowering 
branch, (b) Submerged leaf. ( c ) Flower, id) Petal (one enlarged), (e) Ovaries. (/) Achenes (enlarged). 
Huntingdonshire (E. W. H.). 
Exsiccata : — Billot, 1102, as Batrachium godroni ; 2803, as R. godroni (corrected later to R. radians)', Fries, 
xv, 28, as B. confusum\ Schultz {FI. Gall, et Germ.), 1202, as R. godroni ; Schultz et Winter {H. Ni), i, 6, as 
B. langii', Ft. Austr.-Hung., 1705, as R. paucistamineus var. heterophyllus', Herb. FI. Ingric., 13 b, as R. aquatilis 
var. truncatus. 
This is the heterophyllous form of R. trichophyllus, with floating leaves which are divided deeply or even into 3 cuneate 
segments, the middle segment often being stalked. It is sometimes mistaken for R. triphyllus, and sometimes for R. obtusi- 
florus. 
We have seen specimens of this var. tripartitus from Cambridgeshire, Warwickshire, Staffordshire, and Lancashire; and 
it doubtless occurs elsewhere. It is widespread in Europe. 
(/ 3 ) var. tripartitus forma penicillatus comb. nov. ; Batrachium penicillatum Dumortier in Bull. Soc. 
Roy. Bot. Belg. ii, 216 (1863); R. pseudofluitans Newbould in Thirsk Bot. Exch. Club Rep. for i86q, 5 (1865); 
in Babington Man. ed. 6, 7 (1867); non Baker and Foggitt ; R. hydrocharis form penicillatus Hiern op. cit. 
98 (1871); R. penicillatus Babington Man. ed. 7, 7 (1879); P- diversifolius race penicillatus Rouy et Foucaud 
FI. France i, 64 (1893). 
leones ; — Camb. Brit. FI. iii. Plate 158. {a, b) Flowering shoots. ( c , d) Leaves out of water. ( e ) Flower. 
if) Achenes (enlarged). Devonshire (W. P. H.). 
Submerged leaves with laminae 2 — 6 times as long as the petioles ; segments long, capillary, 
1 Schrank’s diagnosis is very meagre; but he cites Haller op. cit. no. 1162, just as Chaix (toe. cit.) does in founding his 
R. trichophyllus. It is legitimate therefore to refer R. trichophyllus Chaix and R. divaricatus Schrank to the same plant : in 
fact we do not see that any other course is defensible. 
2 Corbiere here cites the name as of Hiern ; but we do not know where Hiern described a plant of that name. 
