166 THE JOURNAL OF BOTANY 
In Europe the following may be given :— 
rance: Doubs, 1738 to 2697 th. risa 3584 to 3816 ft., 
Magnin, with specimens from each elevation. Switzerland : Bet- 
tensee, Upper Valais, 6500 ft., Marshall, sp. P. pralongus is 
capable of bearing greater cold than Jucens, as I have proved by 
actual experiment in an open iron tank. In Europe it extends 
northwards to Swedish Lapland, 68° 5’, Lestadius; Arctic Norway, 
69° 56’, Norman; Finnish Lapland, G6°..657, (67°: 12",. 67°. 49%, 
Wainio, Act. Soc. fenn. viii. n. 4, 71 (1851); Russian Lapland, 
above 68°, Hjelt, Fl. Fenn. 528. It was reported to Hjelt by 
Enwald as occurring in Lapponia inarensis, and Lapponia tulo- 
mensis, between 68° and 69° "50, In Finland lueens is not recorded 
north of 6 67° 10’, Hjelt, l.c. Pr alongus is not on record for Green- 
land or Iceland, but occurs in the Faroes ! 
In Britain it occurs in Shetland (Beeby, sp., aie Caithness 
(Grant, sp.), and Sutherland A sesbnld p.); and beyond the records 
in Top. Bot. ed. 2 2, I have s or oe Eee for eighteen other 
<Pinmhe There is a nites en in Clifford’s herbarium under the 
ame of ‘ P. aquis immersus, aaae pelincids, lato, oblongo, acuto; 
de icbaobais ” has been added by another hand. Smith (Engl. Flora) 
gives this under erongtn reliewag to Rati Syn, 148 (1724); Hudson 
and others do same, 
The species bias not had many named varieties ; the following 
may be mentioned :— 
oliis angustioribus Hook. Brit. Fl. ed. 8, 77 (1835). 
Var. latifolius Alpers in herb. Buchenau. 
Var. ‘eee Célak. si fie Gew. hfe 36 (1886), 
f. elegans Tiselius, Pot. su xsice, eee 85 (1 885), which is a 
long siridve inches) pellucid- ibived to 
The follow g hybrids are asiged to it :— 
ad pialchigus” x crispus Caspar 
P. pralongus x gramineus Rich: & Grach. Fl. Mitt. Europ. i. 
880 (1897). 
P. prelongus x perfoliatus Ar. Benn. in Journ, Bot. 1894, 153. 
his is not the same as P. cognatus Asch. & Grab., l.c., though so 
considered by these authors. The American plant named by me 
prelongus x perfoliatus may therefore bear the name x P. intermixtus. 
- bucens X pralongus = x P. Babingtonii, Ar, Benn. in Journ. 
Bot. 1894, 204. 
F. alpinus x _prelongus According ho Asch. & Grab., 1. c, 817. 
= P. Gri rifithti Ar. Ben This conclusion I cannot accept ; 
my opinion is based upon ae Willkeention of the plants side by side. 
here is another possible hybrid 
th 
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