LICHENS OF THE STATE OF WASHINGTON 



35. Thalline margin absent, spores 1-septate 28. Solorina 



35. Thalline margin present, spores 1-septate or muriform 



69. Physcia 



34. Spores hyaline. 



36. Spores polar-bilocular ; thallus red, purple, or violet with 



KOH 66. Xanthoria 



36. Spores nonseptate. 

 37. Upper cortex poorly developed, thallus always small, 

 often covered with soredia or breaking up into pow- 

 dery masses 53. Parmeliopsis 



37. Upper cortex well developed, thallus various in size 



54. Parmelia 



5. Perithecia and apothecia both absent. 

 38. Thallus growing on rocks immersed in water. 



39. Always found growing in mountain streams ; algal component blue-green. 



25. Hydrothyria 



39. Not always in mountain streams; algal component green 



4. Dermatocarpon 



38. Thallus not growing on rocks immersed in water. 



40. Thallus squamulose. 



41. Thallus red or purple with KOH 65. Caloplaca 



41. Thallus not red or purple with KOH. 



42. Always a blue-green algal component 21. Parmeliella 



42. Always a green algal component. 



43. Attached to substrate by hyphal rhizoids; no lower cortex 



51. Candelariclla 



43. Attached to the substrate by rhizoids or an umbilicus. 



44. Thallus very small, thin and dainty, upturned edges sorediate 



3. Normandina 

 44. Thallus larger, thicker and coarser; edges not upturned, not 



sorediate 4. Dermatocarpon 



40. Thallus foliose. 



45. Thallus attached to the substrate by a single umbilicus or several cords. 

 46. Thallus thin and papery when dry 42. Umbilicaria 



46. Thallus never so thin and papery when dry 4. Dermatocarpon 



45. Thallus not attached to the substrate by a single umbilicus or several 



cords. 



47. Thallus red or purple with KOH. 



48. Thallus with both upper and lower cortices, with rhizoids or a 

 definite holdfast 66. Xanthoria 



48. Thallus not as above, usually yellow or orange. 65. Caloplaca 



47. Thallus not red or yellow with KOH. 



49. Small, rather delicate lichens. 



50. Medulla cottony 69. Physcia 



50. Medulla not cottony. 

 51. Thallus with both upper and lower cortices; spermatia lateral. 



52. Candelaria 



51. Thallus with only a lower cortex 53. Parmeliopsis 



49. Larger, coarser lichens. 



52. Lower surface of thallus tomentose or villous, interrupted by 

 cyphellae or naked, light-colored, inflated spots. 

 53. Lower surface interrupted by cyphellae 27. Sticta 



53. Lower surface interrupted by naked, light-colored, inflated 



spots 26. Lobaria 



52. Lower surface of thallus not as above. 



54. Thallus upright, ascending, rhizoids usually lacking on lower 



