110 Мовтем P. Ровзию. 
petalum Hausskn. (tenuiflorum Tu. Ев. & LGE.) seems to lie within the 
limits of variation of any patch and thus hardly to deserve the name. 
On the other hand the var. albiflorum Naru. is hereditary constant. 
This fact may especially be observed at the borders of river beds, where 
a series of colonies may he started from a single patch and occuring 
along one branch of the river, but not along the others. 
; 218. Chamaenerium ambiguum Tu. Fr. & LANGE 
(? Ch. angustifolium X latifolium). 
Strange to say this presumed hybrid has only been observed on 
Disko, but in return rather often. In Lyngmarken at Godhavn it has been 
found at least five times, and at Sinigfik 69°22’ also rather often; but 
it seems only to occur in few specimens. | have not been so fortunate 
as to find it myself in spite of intense searching in places where both 
species were growing side by side. The specimens from Sinigfik were 
collected flowering, Aug. 11. 1907, and the collector (L. GEISLER) adds 
the information that it was growing among Ch. latıfolium and Ch. an- 
gustifoliuum, and that the last was not yet flowering. Its ovaries are big 
like those of latifolium, but they shrink in drying, and the ovules shrivel 
completely; thus it seems incapable of fruiting. 
XXIX. Halorrhagidaceae. 
L 219. Myriophyllum spicatum L. var. capillaceum LANGE. 
In ponds and pools. 
Only observed a few times. Sofiehavn at Tasiussarssuaq 68°25’ (Bl.); Itivneq 
at Holsteinsborg (W. & H.); in a lake at the head of S. Stromfjord 66°55’ (Jens.); 
found a few times at Ikerasak 70°30’ (S. Н. Vh.). 
A decided southern type in Greenland; only known from the 
mentioned places. 
Some of the specimens from Ikerasak collected by VANHOFFEN 
were flowering already on the July 22, and therefore I suppose it may 
be able to fructificate. 
Hibernates under ice. 
XXX. Hippuridaceae. 
A 220. Hippuris vulgaris L. 
Will hardly be wanting in any smaller lake or pond which do not 
dry up during the summer. It is the most common and widest distri- 
buted aquatic plant of Greenland. 
