12* 



1. U. barbata (L.) Fr. : thallo irregulariter ramoso, glauco; apothe- 

 ciis concoloribus, fibrilloso-radiatis. 



Syn. Lichen Wnbg. Fl. Lapp. p. 437. Usnea barbata Fr. Lich. 

 Ear. p. 18, Schaer. Enum. p. 3, Mass. Mem. p. 73 (excl. <). 



a,, florida (L.): thallo erecto, ramosissimo, scabrido; apotheciis 

 amplis. 



Syn. Usnea florida Ach. Univ. p. 620 , Syn. p. 304 ; K o e r b. Syst. p. 3. 

 Usnea florida /?. comosa Smrft. Suppl. p. 116. 

 Exs. L. Su. n. 120. Mass. n. 51. 



/3. plicata (L.): thallo subdichotomo, pendulo, laevigato; apotheciis 

 minoribus. 



Syn. Lichen ramis JUiformibus ramosis pendulis confertis L. Lapp, 

 n. 457. 



Usnea plicata Ach. Univ. p. 622, Syn. p. 305; Koerb. Syst. p. 3. 

 Usnea florida p. comosa b. plicata Smrft. p. 116. 

 Exs. L. Su. n. 270. 



In meridionalibus tantummodo regionum arcticarum partibus parce 

 occurrit, ut "in arboribus praecipue Betulis Lapponiae sylvaticae passim" et 

 "in lignis Nordlandiae inferalpinae admodum brevis" (Wnbg.). Forma a. 

 in Saltdalen Nordlandiae a Sommerfelt lecta est parce quidem sed abun- 

 de fructifera et cephalodiis carneo-pallidis instructa; /3. eodem loco et in 

 Lapponia Kemensi sterilis. In iota autem Finmarkia, Groenlandia ceterisque 

 terris mere arcticis certe deest 







Species omnibus bene cognita , admodum varians. Nullos certos potui 

 invenire limites inter formas floridam, hirtam, plicatam, dasypogam, quare 

 auctores has in unam speciem conjungentes secutus sum. Sporae subellip- 

 soidae, simplices, octonae, hyalinae, O.ooc s mm. longae et 0,oo.t 4 mm. latae; 

 asci minuti, clavati, paraphysibus arete conglutinatis obvallati. Kamuli formae a. 

 in his regionibus saepe sunt sorediato-pulverulenti. 



2. U. melaxantha Ach. : thallo erecto, ramoso, ramis primariis ochro- 

 leucis, nigro-vittatis 1. annulatis, extremis subsimplicibus, plus minus nigris; 

 [apotheciis planiusculis , disco nigro, margine nudo.] 



Syn. Usnea melaxantha Ach. Meth. p. 307, Univ. p. 618, Syn. p. 303. 



Usnea sphacelata R. Br. Flor. Melv. in Verm. Bot. Schrift. I. p. 458. 



Ad rupes 1000 circ. pedes supra mare elevatas insularum Spitsber- 



gensium a Scoresby detecta et dein a multis (Martins, J. Vahl, Nor- 



