342 DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 



rightly. L. jJeiidula, Ait., is the same plant ; and I can find nothing to warrant the 

 separation of L. Dahurica, P. & Turc, from these. 



JuNiPERTJS nana, Willd. Fries makes of this a variety of communis, L. (as do Watson, 

 Koch, and Ledehour), 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 dij6B.culty distinguished from J. Sahiua, L. 



MONOCOTYLEDONES. 



Sagittaria variabilis, Engelm. This is extremely closely allied to and the represen- 

 tative of S. sagitta^folia ; 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 sparganifoUus, Lsest. Pries and Ledehour both retain this as a distinct 

 species, the former noticing its very close affinity with natans. 



jP. temiissimiis, M. K. Pries makes of this a Lapponian variety of j^«si/^?ts; Ledehour 

 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. lieterophyllus, Schreb. Pries, Koch, and Ledehour all agree in considering this a 

 form of gramineus, L. 



ToFiELDiA borealis, Wahl., is the same with T. palustris, L. 



Veeatrum viride, Ait. Asa Gray says of this, " too near the European V. alburn^ 

 The chief character lies in the breadth of the segments of the perianth, which, how- 

 ever, varies considerably in both. 



V. Lobeliamim, Bernh., is album j3, floribus viridibus, of Chamisso and Ledehour, a very 

 arctic form. 



Allium Sibiricum, L. Ledehour 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 Liudley and of the ' Plora Boreali- Americana.' 



Platanthera hyperborea, Lindl. Iceland is the only European locality for this plant. 

 Prom Lindley's observations and those in ' Plora Boreali- Americana,' there is no doubt 

 that dilatata, Lindl., and Koenigii, 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 



