141 
Potamogetonaceæ from Asia. 
By O. Hagström. 
The following plants are collected by D:r S. 
Hedin during his journeys in Asia. The material 
only comprehends 3 species of Potamogeton: P. per- 
foliatus, pectinatus and filiformis. 
Potamogeton. 
1. P. perfoliatus L. 
”Sorun-Köll. 7. 10. 99” ”Ullug-Köll.” Leaves of 
the stem 3 — 3,5 X 1 cm., leaves of the branches 
2 X 0,8 — 0,5 cm. 
The stem is in its anatomical structure congru- 
ent with our European forms of the species. 
2. P. pectinatus L. v. coronatus n. var. 
”Muntjokk-ott 23 juni Mapiek-köll”. Fruiting spe- 
cimen; only its upper part preserved. Stem slender, 
thin (1 mm. in diam.), branched, internodes 5 — 10 
cm. Leaves narrow (1 mm.; on the branches 1 | 2 mm. 
only), acute; stemleaves and lower branchleaves cuspi- 
date. Sheaths with membranaceous border. Stipules 
half as long as the sheaths. Peduncles 5 — 10 cm. in 
length. Spikes of 5 — 8 (usually 5 — 6) sections. Fruit 
small , 3 X <2 mm ., back rounded (dry with a low keel 
on the back below). 
The anatomy of the stem like that of the Eu- 
ropean forms: endodermis-cells strongly onesided thic- 
kened, spread bastbundles (11 observed in a trans- 
verse section at the middle of the stem) in one circle 
in the bark, central cylindre compressed (transv. sect, 
oval). The small drupelets make this form easily 
recognizable. 
3. P. filiformis Pers. 
Typical forms observed from ’’Tibet, i sjö 26 
aug. 01”, ’’Läjer 79. 12 sept. Liten sjö”. 
