17 



ture, and the tendency oi the tips to rise 5 mm. or so from tlie 

 foothold. N. hclvetictim, a more common subspecies, has the mar- 

 gins toothed and splitting into small lobes and coral-like growths. 

 N. parile has blue-gray soredia along the margins. N . lacvigatnm 

 is smooth on both surfaces. All three subspecies are distinguished 

 by the absence of whitish tubercles. From species of Peltigera, all 

 these are separated by the want of any thickened veins or large 

 root-like holdfasts. 



Nephroma helveticum. Swiss Lichen 



Also called A'', resupinatum forma helveticum. A subspecies 

 found on rocks or mossy trees in deep woods throughout the New 

 York area, fairly frequent in western New Jersey. It spreads 

 irregularly in dense mats up to 10 cm. or more across, with 

 branches, when they can be measured, usually about 5 mm. wide,, 

 but these divide into many thin, fan-like lobes, rising often 1 cm. 

 from the foothold, the crinkled margins commonly covered with 

 coral-like growths and granules. The upper surface is typically 

 leather-brown, but may be grayish or purplish. The under surface, 

 pale brown and minutely wrinkled near the margins, becomes black 

 and complicated towards the center, where it is clothed with a 

 downy nap. 



Fruits scarce, up to 6 mm. across, occupying the under surface 

 of special lobes, reddish brown. Spores brownish, 4-celled, 15 to 

 22 by 5 to 9 microns. 



As N. helveticum is usually found sterile, it is not easily iden- 

 tified by one who does not know it, yet has a characteristic appear- 

 ance. The many coral-like growths and miniature lobes decorating 

 the crinkled margins, make it more complicated than any other 

 non-gelatinous, brown lichen discussed here, except perhaps Phys- 

 cia aquila var. detonsa (Group 8) and Pannaria micro phylla 

 (Group 10), both with much narrower parts. A^. helveticum is of 

 thinner texture than the other members of Group 7. From all 

 Shield Lichens (Groups 5 and 6) and BHster Lichens (Group 8) 

 it can be distinguished by the dull blue-green color of the algal 

 cells and their tendency to cling in chains. The Jelly Lichens 

 (Group 11) have a gelatinous look when wet, and a much simpler 

 microscopic structure. But N. helveticum will be difficult to de- 

 termine with any certainty until it has been seen in fruit, which 



