Table XLIX. List of plants tested for N fixation which showed no 

 evidence for acetylene reduction activity. 



Site A 



Arctostaphylos alpina 



Vaccinium uliginosum 



Salix arctica 



Rhododendron lapponicum 



Alectoria (4017) 



Cladonia (4012) 



Cladonia (4011) 



Cetraria Islandica (L.) Ach. (4007) 



Cetrarla cucullata (Bell.) Ach. (4009) 



Sphaerophorus globosus (Huds . ) Vain. (4021) 



Cetraria nivalis (L.) Ach. (4023) 



Cetraria tilesii Ach. (4018) 



Asahinea chrysantha (Tuck.) W. Culb . and C. Culb . (4015) 



Thamnolia subuliformis (Ehrh.) W. Culb. UV and (4016b) 



Alectoria (4019) 



Cladonia in tundra pool, saturated but no standing water (4004) 



Umbilicaria (4030) 



Solorina crocea (L.) Ach. (4002) 



Baeomyces roseus Pers . in kettle, sloping side (4005) 



Rhizocarpon geographicum (L.) DC. (4026) 



Alectoria (4024) 



Site B 



Vaccinium uliginosum 

 Ledum decumbens 

 Betula glandulosa 

 Pedicularis labradorica 

 Equisetum sylvaticum 

 Polygonum bistorta 

 Carex bigelowii 



Cetraria richardsonii (Hook.) (4031) Site B dwarf birch tundra 

 Dactylina arctica (Hook.) Nyl. (4028) Site B open dwarf birch tundra, 

 well-drained area 



Site € 



Acetylene reduction activity was measured in connection with all plants 

 from site C. However, some of the production rates were low, and pending 

 N-15 confirmation, acceptance of nitrogen fixation activity by the plants 

 must be tentative. Contaminant blue-green algae included with the plant 

 in the experimental containers seems possible in these aquatic samples. 



Site D 



J uncus castaneus 

 Ranunculus aquatilis 

 Petasites f rigidus 



121 



