AQUATIC FORMS AND SPECIES OF THE BRITISH FLORA 23 
depth of water (6 dm.!), and 10 mm. wide. This I have 
gathered in Surrey, and seen in Norfolk. 
A North-American species, S. heterophylla, Pursh, has 
established itself in the River Exe, near Exeter, Devon. 
Sparganium.—Dr. Rothert has found in the late Mr. 
Beeby’s herbarium two specimens of Sfarganium from 
Shetland that recede from S. sznzmum and approach S. 
hyperboreum, Laest., “ Bih. i. bot. arsber,” 1850. A species 
of N. Finmark, S. Norway, N. Sweden, Finnish and Russian 
Lapland, N. Finland, Iceland, Greenland, Labrador, and 
Hudson’s Bay. 
S. glomeratum, Laest., lc. (S. fluttans, Fr.), is another 
Scandinavian species that should be sought for; this occurs 
as far south in Sweden as Scania. 
In another work? Glick’s ideas are still further worked 
out, and many figures (Nos. 324 to 379) are given of varying 
forms, leaf and other sections. 
But in neither work are there any attempts to clear up or 
collate the many other names under these species given in 
European floras (mainly under Adzsma). Neither do Ascher- 
son and Graebner, in their review of these genera, account for 
many named varieties. 
The following experience will show the sequence of a 
species of aquatic (Damasonium Alisma, Mill.) that does not 
reach Scotland, but which I watched through the summer of 
1887 on a common (Mitcham) near here. It had then several 
ponds, many ditches, and swampy places on a gravelly soil. 
In one pond (since filled up) the above plant grew pretty 
abundantly. In April it was the form gramznifolium, Glick ; 
in May it began to make itself into the form spathulatum, 
Gliick; at the end of June it had become the form zatans, 
Gliick; flowered through July and part of August; at the end 
of August the water became very low, and the plant here and 
there became stranded ; it was now the form ¢errestre, Gluck. 
The only one I could not say I saw was the form pumzla, 
Gliick, which he describes as “ misera forma terrestris semine 
Mata, etc.” 
1 Hiern., ‘Exch. Club. Rep. for (1908),” p. 399, 1909. 
2 “Tebensgeschichte der Bliitenpflanzen Mitteleuropas,’ by Drs. 
Kirchner, Low, and Schréoter, 1907. 
