ON POTAMOGETON TRICHOIDES, VAR. TRIMMERI. 273 
Note on the Variety Trimmeri of Potamogeton trichoides, Cham., 
found in England. By Roserr Caspbaty, Professor of Botany, 
Königsberg, Prussia. Communicated by Dr. Hooxzz, V.P.LS. 
[Read December 15, 1864. ] 
Amonest the Potamogetons of my herbarium is one, collected by 
my friend the Rev. Mr. Trimmer, of Norwich (Sept. 1850), in a 
pond near Framingham Earl, Norfolk, which I do not find men- 
tioned in those British Floras I have at hand (Eng. Bot. cum 
Suppl.; Babington, Manual, 1848; Hook. & Arnott, Brit. Fl. 
1850*), and which therefore may perhaps be new to England— 
-Potamogeton trichoides, Cham. (Linnea, 1827, ii. 275). I received 
this plant from Mr. Trimmer himself during my two years and a 
half’s stay in England. It is not that variety of this species which 
Chamisso described and figured (l.c. tab. 4. fig. 6), and which 
was also represented by Reichenbach (Icon. Fl. Germ. 1845, vii. 
t. 21), and named by Ascherson (Fl. der Mark Brandenburg, 
665) (b) leiocarpus, having only under the middle of the interior 
margin of the caryopsis a large tubercle, and a smooth carina 
(“fast ganzrändigen Kiel,” Aschers.) ; nor is it that form which 
Fieber (Die Potamogetonen Böhmens: Prag, 1838, tab. 4. fig. 22) 
knew, and which Reichenbach mentions as P. trichoides B. tuber- 
culosus (l. c. tab. 22. fig. 35) ; but it is a form intermediate between 
these two. The caryopsis of Fieber and Reichenbach's plant, 
P. trichoides (). tuberculosus, Reichenb., has a tubercled carina, and 
a large tubercle on either side of its base under the tubercle of 
the interior margin t. But the plant of the Rev. Mr. Trimmer, 
although it has well-defined tubercles on the back of the caryopsis, 
has no lateral tubercle below that of the interior margin. I de- 
signate this form as P. trichoides var. Drimmeri. 
Königsberg in Pr., 
26 Nov. 1864. 
[* The station for this plant near Norwich is given in the 7th edition of 
Hooker and Arnott's * British Flora? (1855) and in the 4th edition of Babing- 
ton's ‘Manual’ (1856). Dr. Caspary’s critical notes, however, appear to be of 
sufficient interest to be placed on record.—ED. ] 
t It is possible that * Potamogeton tuberculatum,” Tenore et Gussone (Me- 
morie sulla Peregrinazione, lette alla R. Accad. delle Scien. 1834-38, Napoli, 1842, 
P. 150; Tenore, Sylloge, App. v., Napol. 1842, p. 4), which Ascherson, l. c., 
unites with his P. trichoides a. tuberculatus, is synonymous with P. trichoides 
B. tuberculosus, Reichenb., as the caryopsis is represented “tuberculo unico 
utrinque? (Tenore, Syll. Lei and “ad carinam pluritubereulata” (Ten. et 
- Guss. Mem. /. c.); but as the leaf is described as “obtusiusculum” and the 
caryopsis as “ obsolete reticulato-nervosa ” (Ten. et Guss. 7. e.), which is never 
found in P, trichoides, Cham., I cannot decide the question without seeing an 
