166 LEPTOGIUM. 



Maine, fertile, Oakes. And infertile specimens, probably refera- 

 ble here, by the characters of the under side, have been found 

 by me in Massachusetts ; and in the Blue Ridge of Virginia. The 



lichen has also occurred in Madeira, Mandon! From the 



Madeira plant, which is well referred here by Nylander, the L. 

 inflexum of this writer (Syn. 1, p. 132; and found in Mexico; 

 Venezuela, Fendler I New Granada, Lindig n. 127! 2504! and 

 Bolivia, Mandon ! ) offers no differences beyond a rather better 

 thalline development (e. g. wider sinuses than appear to be com- 

 mon in the northern lichen), and none are indicated in the pub- 

 lished diagnosis. As in the next species the upper side is now 

 also downy, both in the northern and southern plants. This side 

 is said now to be 'isidioso-furfuraceous,' and the margins of the 

 lobes to be ' isidioso-dissected ' in a New Granada form (L. in- 

 flexum v. isidiosulum, Nyl., which we are further told 'ought 

 perhaps to be distinguished in species,' though no other differ- 

 ence is noted, Nyl. Prodr. N. Gran. p. 4), and our New England 

 plant varies in like manner, the whole upper side being covered 

 now with isidioid lobules. 



21. L. myochroum (Ehrh. ; Schaer.) Tuckerm. ; thallus ample, 

 coriaceous-membranaceous, from rosulate and sub-monophyllous 

 passing readily into polyphyllous and loosely aggregate states, 

 laciniate-lobate ; lead-coloured (rufous-glaucous) and blackish- 

 green ; smooth at first, but becoming now rugose, and always 

 more or less granulate ; the rounded, undulate lobes entire be- 

 neath clothed with a whitish-ash-coloured nap ; apothecia mid- 

 dling-sized, lecanorine, sub-sessile, flattish; the disk red-brown, 

 with a plicate-rugose, thalline border, which becomes now gran- 

 ulate-leafy, and now white-hirsute. Spores ellipsoid, from 4-loc- 



ular becoming sub-muriform, decolorate, -^- raic. Collema, 



Schcer. Spicil. p. 534 ; Enum.p. 256. Leptogium, Tuckerm. Gen. 

 p. 99. L. saturninum, L. Hildenbrandii, & L. Menziesii, Nyl. 

 Syn. 1, p. 127. 



a. saturninum, Schaer. ; commonly glaucous, or now rufous 



and somewhat rugose above ; fleecy beneath. L. saturninum 



(Sm. 1788), Mass. L. Hildenbrandii, Oarov., & Authors. 



b. tomentosum, Schser. ; thinner, blackish-green, now narrowed 

 and sinuate-lobate, and passing into small-lobed, imbricate-com- 



plicate states ; velvety beneath. Collema tomentosum, Hoffm. 



C. saturninum (Dicks. 1790), Ach., Nyl. 



