342 DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 
rightly. L. pendula, Ait., is the same plant ; and I can find nothing to warrant the 
separation of L. Dahurica, P. & Turc., from these. 
Junipertjs nana, Willd. Pries makes of this a variety of communis, L. (as do Watson, 
Koch, and Ledebour), which is distinguished by the broader, incurved leaves. Every in- 
termediate grade of leaf may be found uniting them. 
J. prostrata, Pers. The Arctic American plant is certainly nothing but a stunted 
form of Virginiana, and is with difficulty distinguished from J. Sabina, L. 
MONOCOTYLEDONES. 
Sagitt^ria variabilis, Engelm. This is extremely closely allied to and the represen- 
tative of S. sagittcefolia ; it is chiefly distinguished by the absence of purple on the claw of 
the petals. The latter plant is Arctic Russian, but not Lapponian. 
Potamogeton sparganifolius, Lsest. Pries and Ledebour both retain this as a distinct 
species, the former noticing its very close affinity with natans. 
P. temiissimus, M. K. Pries makes of this a Lapponian variety of pusillus ; Ledebour 
follows him. 
P. nigrescens, Pr. Under this Pries doubtfully includes lanceolatus, E. Bot. He 
observes its very close affinity with gramineus, and that P. coloratus, Hoffm., is wholly 
intermediate. 
P. heterophy litis , Schreb. Pries, Koch, and Ledebour all agree in considering this a 
form of gramineus, L. 
Tofieldia borealis, Wahl., is the same with T. palustris, L. 
Veratrum viride, Ait. Asa Gray says of this, " too near the European V. album. 
The chief character lies in the breadth of the segments of the perianth, which, how- 
ever, varies considerably in both. 
V. Lobelianum, Bernh., is album /3, floribus viridibus, of Chamisso and Ledebour, a very 
arctic form. 
Allium Sibiricum, L. Ledebour unites this with Schcenoprasum ; Pries keeps them 
distinct, regarding the latter as a cultivated plant only. 
Orchis sambucina, L. The distribution of this is peculiarly wide in some respects for 
an Orchideous plant, extending diagonally through Europe from Lapland to the confines 
of N.E. Persia in Karabagh. 
Peristylus bracteatus, Torr. This and P. Islandicus, Lindl., are so very closely allied 
to viridis, that they can hardly rank as anything but forms of that plant. This would 
appear to be the opinion of Lindley and of the c Plora Boreali- Americana.' 
Platanthera hyperborea, Lindl. Iceland is the only European locality for this plant. 
Prom Lindley's observations and those in * Flora Boreali- Americana,' there is no doubt 
that dilatata, Lindl., and Kcenigii, Lindl., are states of the same. Asa Gray further adds 
that Huronensis is a synonym of hyperborea, and that dilatata is too near the same. 
Epipactis media, Pr. This its author makes a distinct species, and does not include 
the true latifolia in his Lapland list. Koch refers it to rubiginosa, Gaud., distinguished 
