No. VII.] 



LIST OF THE PLANTS. 



759 



Thallus lacero-laciniatus, supra densissime purpureo-rugosus, subtus magis aut minus reticulato-lacuno- 

 sus, glaber. Apothecia difformia, angulata, convexa, plicis utplurimum circinatis notata. Praecedenti 

 affinis et fortasse varietas senilis. (B.) 



Expl. Iconis eadem ut in praecedenti. 



553. G. pensylvanica : Ach. Syn. p. 67. Muhl. Cat. p. 105. Tab. 30. Fig. 2. 



Thallus tenuis umbilicatus, irregulariter expansus flexuosus, passim erosus, in ambitu lacero-laciniatus, 

 supra umbrino-brunneUs, plerumque prope umbilicum materia quadam Crustacea canescens, papulis elevatis, 

 oblong-is vel conoideis, obtusis, sparsis, discretis, saccis paginae adversae respondentibus munitus \ subtus 

 lacunosus, punctis crebris elevatis scaber ; brunnescenti-niger ambitum versus pallidior ; utrinque opacus 

 Madefactus aliquantulum pallet et supra olivaceus vel aeneo-fuscus evadit. 



Apothecia simplicia adpressa, orbiculata vel flexuosa angulataque, disco opaco, piano vel concaviusculo, 

 eequabili interdum ostiolo centrali impresso et margine proprio elevato nitidiusculo cincto. Apothecia ali- 

 quando in discis suis alia minora ferunt vel cum aliis confluunt quibus modis formatur apothecium satis 

 magnum disco planiusculo irregulariter plicato margine communi flexuoso, et angulato cincto. Sunt 

 quoque in thallis quibusdam fortassin vetustioribus apothecia dissimilia parva, discreta, aut conferta, discis 

 depressis et marginibus granulato-crenulatis, rugosis, inflexisque. Apothecia vetustiora utriusque generis 

 in ambitu a thallo elevata sunt. 



Thallus interdum locos humidos opacos habitans flavescenti-cinereus fit. (B.) 



Expl. Icon : a. superficies thalli supina, h. superf. prona mag. nat. e. apothecium et portio thalli exsecti 

 sub lente visi. 



554. G. Muhlenbergii : Ach. Syn. p. 67. Muhl. Cat. p. 105. 



Thallus hujus quam trium praecedentium paulo crassius, plerumque polyphyllus, hepatico-brunneus, 

 extrorsum fere nigricans, oblique umbilicatus, flexuosus, prope umbilicum capillaceo-brunneus corrugato-pli- 

 catus, plerumque irregulariter expansus, margineque lacero, hie illic pertusus erosusque ; supra glaber, niti- 

 diusculus, foveolis ab apotheceis impletis ambitum versus praecipue impressis ; subtus sordide flavescenti- 

 brunneus, minute verrucosus, at fixuris cribriformibus nigrescentibus fere obtectus. Apothecia majuscula vix 

 unquam orbiculata, fere semper angulata, et non raro pulchre stellata, convexa, densissime plicata non 

 semper in sacculis immersa sed etiam in plana superficie thalli sessilia. Dantur quoque in eodem thallo 

 apothecia alia parva fere orbicularia, disco depresso et margine granulato rugosoque inflexo. 



Expl. Icon, a superficies thalli supina, b superficies partis thalli prona mag. nat. e. pars thalli cum apo- 

 thecio exsecta, et sub lente visa. 



Hab. This and the three preceding species were found in greater or less abundance in all rocky places 

 throughout our journey. We used them all four as articles of food, but not having the means of extracting 

 the bitter principle from them, they proved noxious to several of the party producing severe bowel com- 

 plaints. The Indians use the G. Muhlenbergii, rejecting the others, and when boiled along with fish-roe or 

 other animal matter, it is agreeable and nutritious. On the Barren Grounds this lichen is scarce, and we 

 were obliged to resort to the other three, which served the purpose of allaying the appetite, but were very 

 inefficient in recruiting our strength. 



555. G. vellea, Ach. Syn. p. 68. Umbilicaria vellea. Mich. Fl. Am, ii. p. 323. 



Thallus crassiusculus, molliusculus, saepe lati1;udine sesquipedalis, sordide flavescenti-griseus (sub lente 

 verrucosus) pertusus erosusque, in ambitu sub rotundato-lobatus, lacerusque ; subtus fibrillis densis brevi- 

 bus, furcatis, nigris, hirsutus. Apothecia nunquam inveni. 



Hab. on shady and moist rocks, most luxuriant in woods. This is more agreeable to eat than any of 

 the preceding species, but we met with it very sparingly on the Barren Grounds. 



556. Opegrapha macularis : Ach. Syn. p. 72. Muhl, Cat. p. 105. (W.) 



