KEY TO KEYS 1. Thallus not entirely leprose, with portions of the thallus distinct not dissolved into soredia/granules; or if leprose then with a distinct well developed prothallus (not Lepraria)....................................................................................…2 2. Thallus AND/OR soralia yellow or orange pigmented................................................................…Key 1 (Page 2) 2. Thallus AND/OR soralia not yellow or orange pigmented, but red pigments can be present............................…3 3. Thallus UV+ bright yellow (lichexanthone present)….................................................................Key 2 (Page 7) 3. Thallus UV-, UV+ dull orange/pink or orange or blue-white (without lichexanthone)..................................…4 4. Photobiont Trentepholia........................................................................................................…Key 3 (Page 9) 4. Photobiont not Trentepholia….........................................................................................................................5 5. Thallus OR soredia with norstictic acid, K+ yellow to red producing large crystals in water mount............ …..............................................................................................................................................Key 4 (Page 12) 5. Thallus OR soredia without norstictic acid, K-, K+ other colors, or K+ yellow to red but NOT producing large crystals in water mount........................................................................................................................…6 6. Thallus squamulose and on bark (Hypocenomyce species)…..........................................Key 5 (Page 11) 6. Thallus not squamulose and on bark (not Hypocenomyce species)......................................................…7 7. Thallus instantly K+ intense lemon yellow, P+ intense orange (thamnolic acid present)...................... ......................................................................................................................................…Key 6 (Page 13) 7. Thallus K-, K+ other colors, or K+ yellow but not usually intense, P+ or P- (without thamnolic acid) ...............................................................................................................................................................…8 8. Thallus AND/OR soralia/medulla C- AND UV+ blue-white (alectoronic acid, confluentic acid, divaricatic acid, perlatolic acid, etc. present)............................................................…Key 7 (Page 14) 8. Thallus AND/OR soredia/medulla not C- AND UV+ blue-white.................................................…9 9. Thallus C+ AND/OR KC+ pink-red (erythrin, gyrophoric acid, lecanoric acid present)................ …...............................................................................................................................Key 8 (Page 16) 9. Thallus NOT C+ AND/OR KC+ pink-red...................................................................................10 10. Thallus AND/OR soralia/medulla K- AND C+ yellow-orange OR KC+ yellow or KC+ yellow-orange (xanthones or usnic acid present), usually distinctly greenish or yellowish in color…...................................................................................................................Key 9 (Page 19) 10. Thallus AND/OR soralia/medulla K+ or K-, C-, KC- (or KC reaction not different from K reaction)…....................................................................................................................................11 11. Thallus distinctly green, often with a white prothallus; isidiate or lobulate; southeastern North America (Phyllopsora)…......................................................................Key 10 (Page 21) 11. Thallus not with the above combination of characters; from anywhere in North America… …………………………………………………………………..…………………………….12 12. Thallus K- or K+ yellowish AND P+ yellow, P+ orange-red, or P+ red (argopsin, fumarprotocetraric acid, pannarin, protocetraric acid, psoromic, or stictic acid present) …… ………………………………………………………………………......…Key 11 (Page 23) 12. Thallus K+/-, P-, UV- (atranorin, and species that do not react to spot tests)..................... .................................................................................................................…Key 12 (Page 26) 1. Thallus entirely leprose and lacking a prothallus (Lepraria s.l.).................................................…Key 13 (Page 30) 1 KEYS TO YELLOW, YELLOW-GREEN, AND ORANGE STERILE CRUSTOSE LICHENS Note: This key does not include species with usnic acid which would be classified as “green”. It does include some xanthone containing species that are often very yellow. These species are also keyed out in the xanthone/usnic acid key. GENERIC KEY 1. Thallus K+ violet/magenta, anthraquinone pigments present in the cortex..........................…Caloplaca/Fulgensia 1. Thallus K- or K+ some other color than above, anthraquinone pigments absent from the cortex.........................…2 2. Growing on soil in arctic/boreal habitats.............................................................................................................…3 3. Thallus UV+ bright orange (rhizocarpic acid)..........................................Arthrorhaphis citrinella (Ach.) Poelt 3. Thallus UV- or UV+ dull orange (calycin?)…..................................Candelariella “granuliformis” Westberg 2. Not growing on soil in arctic/boreal habitats......................................................................................................…4 4. Thallus rusty orange; medulla UV+ blue-white (confluentic acid); on rocks in boreal habitats........................... ....................................................................................…Porpidia melinodes (Körber) Gowan & Ahti (fig. 16D) 4. Thallus distinctly yellow or yellow-green; medulla not UV+ blue-white (confluentic acid absent); ecology various................................................................................................................................................................. …5 5. Corticolous; in the coastal plain of the southeastern USA; soralia punctiform; thallus of thin to indistinct flat green areoles ...Buellia wheeleri R.C. Harris (fig. 20B) 5. Primarily on wood; not in the coastal plain of the southeastern USA; soralia and thallus not as above.........6 6. Xanthones present; thallus C+/KC+ orange.............................................................................................…7 7. On driftwood in maritime habitats of the arctic/boreal regions; thallus areolate with discrete soralia...... ……………………………………………………………...…Lecanora orae-frigidae R. Sant. (fig. 20B) 7. On other substrates in other habitats; thallus granulose/leprose...........................................................…8 8. Thallus leprose, composed of ecorticate granules, rare in North America?............................................ ...........................................................................................................Lecanora expallens Ach. (fig. 20A) 8. Thallus granulose, composed of corticate granules, common in western North America...................... .............................................................................…Pyrrhospora quernea (Dicks.) Körber (fig. 19E-F) 6. Xanthones absent; thallus not C+/KC+ orange; distribution various.......................................................…9 9. Thallus entirely leprose.....................................................................................…see key to Chrysothrix 9. Thallus areolate, at least initially…........................................................................................................10 10. On bark or wood............................................................................................................................…11 11. Thallus composed of corticate granules, 50-100 µm in diameter...................................................... .................................. …...................................Candelariella xanthostigma (Pers.) Lettau (fig. 19A) 11. Thallus composed of soredia arising from the breakdown of areoles….......................................12 12. Asci 8-spored; widespread except in the Great Lakes-Appalachians............................................ ........................................…Candelariella xanthostigmoides (Müll. Arg.) R.W. Rogers (fig. 19B) 12. Asci polysporous; distribution various…...................................................................................13 13. Soredia small, 20-40-(50) µm in diameter...Candelariella efflorescens R.C. Harris & Buck 13. Soredia large, 50-100 µm in diameter.....................…Candelariella xanthostigma (fig. 19A) 10. On non-calcareous rock….................................................................................................................14 2 14. Thallus P+ orange-red (pannarin present w/ zeorin and rhizocarpic acid)............................................ ..................................................................................................…Lecanora subaurea Zahlbr. (fig. 20D) 14. Thallus P- (pannarin absent)…..........................................................................................................15 15. Soralia excavate and crater-forming.................................................…Lecanora reagens Norman 15. Soralia not as above…...................................................Lecanora