PART 1

3. Ascospores brown, 2-celled, 8-11 × 5-6 µm, reticulately ornamented;
isidia thick, long, often recumbent, "branching" by regeneration;
apothecia emergent, doughnut-like; Liberty County.................................................................................. T. eximium R. C. Harris
3. Ascospores colorless, submuriform, 4 × 4-celled, 15-21 × 9-12 µm;
isidia sparse, initially globose; apothecia emergent, resembling Porina nucula Ach.;
unknown substance in addition to psoromic acid; Leon, Okaloosa
and Santa Rosa counties .............................................................................................................. T. halei (Tuck. & Mont.) Zahlbr.
2. Thallus PD- (no substances), thick, filled with crystals, often separating
from the substrate; isidia sparse, coarse; ascospores brown, submuriform,
16-28 × 7-12 µm; south to Sarasota County...........................................................................................................T. santense Tuck.
1. Thallus not isidiate................................................................................................................................................................................... 4
4. Ascospores colorless .......................................................................................................................................................................... 5
5. Ascospores transversely septate .................................................................................................................................................... 6
6. Thallus PD- (no substances); ascomata small, immersed ......................................................................................................... 7
7. Ascospores purple with iodine ................................................................................................................................................ 8
8. Apothecia 0.4-0.6 mm across; thallus poorly developed, not corticate;
medulla not obvious; ascospores 9-15-celled, 25-40 × 6-8 µm;
northern Florida ...........................................................................................................................................T. subtile Tuck.
8. Apothecia 0.2-0.35 m across; thallus usually well developed,
weakly corticate; medulla thick; ascospores 8-13-celled, 25-45 × 6-8 µm;
south to Polk County ............................................................................................................................. T. lathraeum Tuck.
7. Ascospores colorless with iodine, 11-14-celled, 24-38 × 6-7 µm;
apothecial disk mostly flush with thallus; Lake County ..........................................................T. alborosellum (Nyl.) Tuck .?
6. Thallus PD+ yellow or orange; apothecia larger......................................................................................................................... 9
9. Thallus PD+ orange (stictic acid agg.).................................................................................................................................. 10
10. Apothecia with thick, recurved and split margin; ascospores 7-10-celled,
30 × 6-8 µm; Florida Panhandle ......................................................................................... T. dilatatum (Müll. Arg.) Hale
10. Apothecia emergent with broad round pore; exciple free from margin
forming a conspicuous inner ring; ascospores to 30-celled,
120-140 × 15-20 µm; exact locality unknown, known only from
type of Ocellularia floridensis ......................................................................................T. porinoides Mont. & v.d. Bosch
9. Thallus PD+ yellow (psoromic acid); apothecia emergent, round with broad
round pore and smooth margin; exciple separating from margin; ascospores
4-6-celled, 13-18 × 6-7 µm; Franklin and Liberty counties .............................................................T. floridense R. C. Harris
5. Spores submuriform to muriform; thallus PD- (no substances) ................................................................................................... 11
11. Ascospores large, over 50 µm long, 1-4/ascus ...................................................................................................................... 12
12. Ascospores thick walled, 2-4/ascus, 65-90 × 15-20 µm ................................................................................................... 13
13. Apothecia immersed when young, becoming urceolate with low,
thick margin; exciple coarse, pinkish tan, often filling pore and
covering the disk; Panhandle ...............................................................................................................T. adjectum Nyl.
13. Apothecia with large, open pore; margin regular, thinner;
exciple fragile, whitish, free from margin; Duval County ....................................................... T. lepadinum (Ach.) Ach.
12. Ascospores thin walled, IKI-, 1-2/ascus, 50-80 × 15-20 µm; apothecia
white pruinose with erect, jagged margin; south to Hillsborough
County ......................................................................................................................................T. leprocarpum (Nyl.) Tuck.
11. Ascospores 25-35(-45) × 12-15(-18) µm, initially 8/ascus but several may abort;
apothecia small, immersed, radially striate and lacerate; Citrus, Columbia,
Jackson, Leon and Union counties ................................................................................... T. defectum Hale ex R. C. Harris
18