116 THE JOURNAL OF BOTANY 



Godron in this particular matter. Fries's plant indeed seems to 

 be merely a submerged state of B. baudotii Godron destitute of 

 floating leaves, as maintained by N. E. Brown (1891). 



The name " tripartihis " has been applied to at least five 

 different plants (c/. Koch in litt. cited by Godron, 1839), namely, 

 to the two British forms or varieties of B. tripartihis DC, to 

 B. ohtusiflorus, to a form of B. aquatilis L. emend., and to a 

 form of B. trichophyllus Chaix emend.''' 



Of the two British forms or varieties of B. tripartitus DC, 

 one has been referred by Messrs. Groves (1907) to B. lutarius 

 Bouvet (1872) = B. kitarium Eevel (1865). I have seen no 

 authentic specimen of Revel's plant, which has actually been 

 placed by French botanists under B. homiophyllus Tenore 

 \—B. lenormandi Schultz). However, all the British plants in 

 question which I have seen appear to be better placed under 

 B. tripartitus DC than under B. Jiomiophylhis Tenore { = B. lenor- 

 mandi Schultz) ; and this opinion coincides with the view of 

 N. E. Brown (1891). One may perhaps be permitted to doubt if 

 this plant of Revel has really been found in the British Isles ; or 

 is it the case that Revel's plant should be placed under B. tri- 

 partitus DC ? The latter is by no means an untenable view, if 

 one may judge from Revel's description and figure. 



One may now allude to B.petiveri Koch. Koch first used this 

 name in Sturm Deutschl. Fl. (1840), and again in the second edition 

 of his Synopsis (1843). B. tripartitus Nolte (1826) and B. tripar- 

 titus var. ohtusiflorus DC are cited by Koch as synonyms. 

 N. E. Brown (1891) states that there is a specimen of B. tripar- 

 titus Nolte in Herb. Mus. Brit., and that he agrees with Hiern 

 (1871) in referring Nolte's plant to B. confusus Godron ; and this 

 agrees with Hiern's allocation (with which I fully concur) of de 

 Candolle's var. ohtusiflorus. I think too the figure in Sturm 

 (82, 2) may also be referred to the same species, i. e., to B. ohtusi- 

 florus. However, the B. petiveri Cosson and Germain Fl. Env. 

 Paris 10, Atlas, t. 1, fig. 5-6 (1845) is not Koch's plant, being 

 referred (and no doubt correctly) to his B. hololeucos by Lloyd in 

 the various editions of his Fl. de I'Ouest. 



In Koch's Syn. ed. 2 (1843), B. petiveri is subdivided into two 

 varieties, namely, var. minor and var. major. The var. minor is 

 the B. petiveri Koch in Sturm (1840), discussed above. The var. 

 major is regarded (erroneously, I think) by Hiern (1871) as the 

 same as B. triphyllos Wallroth (1840). The latter plant seems 

 rightly placed by Rouy & Foucaud (1893) under their B. diversi- 

 folius { = B. aquatilis L. emend.). It is closely related to 

 B. heterophylhts Babington (1855) non Wiggers (1780) nee 

 Hooker fil. (1884), and is a rare plant. It occurs in the Channel 

 Isles, though I have not seen the restricted plant of Wallroth 

 from the British Isles proper. 



* Chaix (1786) established his E. trichophyllus on No. 1162 of Haller's 

 Hist. Stirp. Helv. ii. 69 (1768) : from this it is necessary to exclude Haller's 

 var, /3 which is R. fceniculatus Gilibert (1782) = i?. circinatus Sibthorp (1794). 

 But see also F. N. Williams in Journ. Bot. xlvii. (1908). 



