Lichens, Genera and Species 



Parmelia saxatilis, (L.) Fr. See Plate XV. 



Habit and habitat. On rocks. 



Vegetative organs (thallus). Greenish or ashen-gray above 

 (sometimes reddish) somewhat ornamented with a fine network 

 and with shallow depressions; black beneath with dense hairs 

 (rhiqoids) reaching the margin, much cleft with narrow lobes, 

 with margins wavy and bordered with a fine white beading 

 (soredia). 



Fruiting organs (apothegm). Chestnut border (thalline ex- 

 ciple), rather thick, somewhat evenly notched. 



Spores. Simple, ellipsoid, colourless. 



Name. The specific name saxatilis, the Latin for "rock," 

 refers to the habitat. 



Parmelia perlata, (L. ) Ach. See Plate VI. 



Habit and habitat. The lichen is found on both rocks and 

 trees. 



Vegetative organs (thallus'). Greenish-yellow, gray green, 

 slate colour and even light brown above; black beneath with a 

 reddish-brown border which rolls up so as to bring the brown 

 lobes in rich contrast to the surface colours. The lobes have no 

 fine hairs on their margins and are frequently covered with a 

 white powder (soredia). 



Fruiting organs (apothecia). Large, greenish-brown, entire 

 margins which split down to the centre when the disk is mature. 



Name. The specific name perlata is the Latin for "widely 

 spread." 



The Wrinkled Parmelia, Parmelia caperata, (L.) Ach. 



Habit and habitat. Grows on trees and rocks to form light 

 pea-green, wrinkled and wavy mats. 



Vegetative organs (thallus). -- Leaf-like, appressed, hori- 

 zontal, cartilaginous; lobes usually broad and rounded with 

 entire margins; the upper surface usually covered with a 

 very light green powder (soredia) ; the under surface, black 

 with a reddish-brown margin and scattered thread-like bodies 

 (fibrils). 



Fruiting organs (apothecia). Cup-shaped, with wavy 

 margins often grainy (sorediferous). 



Spores. Ellipsoid. 



Name. The specific name caperata, the Latin for "wrinkled," 

 describes the habit of growth. 



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