PART 1

5. Ascospores with 6-8 rows of 4-8 locelli each,
23-35 × 11-17 µm; peninsular Florida ..........................P. ochraceoflavens (Nyl.) R. C. Harris
4. Thallus red; hymenium inspersed; ascospores 30-42 × 15-20 µm;
Dade and Monroe counties ................................................ P. cruentata (Müll. Arg.) R. C. Harris
3. Thallus not red, orange or yellow, KOH- ........................................................................................... 6
6. Ascomata fused in groups by their eccentric or lateral ostioles
(pyrenastroid), or pseudostromatic shells fused completely
(melanothecoid)............................................................................................................................. 7
7. Pseudostromata pyrenastroid; pseudostromatal shells not
completely fused into a flat Arthonia like plate ........................................................................ 8
8. Ascospores over 45 × 18 µm; ascomata often only at an angle,
sometimes solitary............................................................................................................... 9
9. Ascospores 45-65 × 18-27 µm; throughout Florida..............................P. ravenelii Tuck.
9. Ascospores 65-85 × 25-32 µm (60-72 × 25-30 µm in
Florida specimen); Columbia County ......................................................Pyrenula sp. 47
8. Ascospores 33-42 × 13-18 µm; ascomata usually
distinctly recumbent; Dade, Monroe and Sarasota
counties .............................................................................. P. astroidea (Fée) R. C. Harris
7. Pseudostromata melanothecoid, looking much like an Arthonia
except for the central ostiole; margins crenulate; ascomata recumbent,
fused at the single ostiole; ascospores with 8 rows of locelli,
33-40 × 12-14 µm; Key Largo, Monroe County .............................................Pyrenula sp. 208a
6. Ascomata solitary, ostioles apical ............................................................................................... 10
10. Thallus UV-............................................................................................................................ 11
11. Postmature ascospores empty, collapsing...................................................................... 12
12. Ascospores over 45 × 16 µm .................................................................................... 13
13. Locelli smaller, spherical, in 8-10 rows of up to 10 each;
ascospores 45-62 × 16-30 µm ............................................................................ 14
14. Ascospores (45-) 50-65 × (18-) 20-26 µm, relatively
narrow with pointed ends; Columbia and Volusia
counties ....................................................... P. mucosa (Vainio) R. C. Harris
14. Ascospores 50-70 × 24 -30 µm, broad with rounded end;
known only from Mississippi............................................................................. .
............................................................... [P. pyrenuloides (Mont.) R. C. Harris]
13. Locelli large, often angular, in 8 rows of up to ca. 6 each;
ascospores 45-60 × 16-22(-25) µm; very common,
throughout the state ..............................................................P. leucostoma Ach.
96