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compressed, the narrow sides arched, the broad sides nearly 

 three times broader than the first, flat and provided with 

 a distinct furrow on each side, so that the stem, transversely 

 cut, has some likeness to the figure of 8. This longitudinal 

 furrow, so characteristic in Potamogeton crispus and therefore 

 indicating the descent from this plant, is most developed on 

 the side of the stem, opposite to the leaf belonging to the 

 internode. The internode is somewhat thickened below. 



The leaves are alternate, two-rowed, sessile, largely 

 amplexicaule, 5 — 6 cm. long, 1 — 2 cm. broad, (on the older 

 shoots shorter) stiff, in their whole length equally broad, 

 arcuate, recurved, often partly folded, more or less undulated, 

 crisped, entire, with broad, round, sometimes hooded, con- 

 tracted tip. The midrib is brownish-green, on each side of 

 it is 1 — 2 larger ribs and in each interstice 1 — 2 smaller 

 ribs. All the ribs are combined by few and fine transverse 

 ribs, the areolas thus formed are longer than broad, only 

 towards the tip they are nearly of an equal length and 

 breadth. On the younger shoots the leaves sometimes have 

 a length of 10—15 cm., with a very broad, reddish-brown 

 midrib. 



The ligules of the older shoots are short, on the 

 upper internodes to a lenght of 1 cm. and 0,6 cm. broad, 

 close amplexicaule, at the top a little spreading, paperlike. 

 At the end they are short and blunt, on the younger shoots 

 and on the autumnal shoots large and at the top somewhat 

 bell-shaped, entire, dilated; lower down cleaved and at last 

 fringed before they quite disappear. 



The peduncles are 3 — 4 cm. long, round and without 

 longitudinal furrow, equally thick in every place, and of the 

 same thickness as the upper internode or somewhat thicker, 

 often curved but with erect spikes. The spikes are 1V 2 — 2 cm. 

 long, thick, cylindrical, somewhat pointed with many, 20—30, 

 close-sessile flowers. 



