Key to all brown-black Caloplaca

Dec. 1995 C. Wetmore

    This key includes all species I have studied and am fairly confident of the identification. There are several additonal undescribed species and some species I have not seen. This is subject to further revision. See my paper in Mycologia 99: 292-314. 1996 (1997).

   Last revised 26 February, 1998.   American species in bold.

1. Thallus brown, areolate; apothecial disks darker brown; spores 12.5-14 X 7.5-8.5 um, isthmus   6-7 Ám; China ..................................................................................................... C. cupreorufa
1. Thallus gray, white or immersed ........................................................................................... 2

2. Spores with 4 locules ........................................................................................................... 3
2. Spores with 2 locules ........................................................................................................... 4

3. On rock; not isidiate; Costa Rica ...................................................................... C. tetramera
3. On bark; isidiate; Hawaii, Nepal ......................................................................... C. spadicea

4. On bark, wood or plants ..................................................................................................... 5
4. On rock ............................................................................................................................ 18

5. Epihymenium blue or bluish purple ...................................................................................... 6
5. Epihymenium gray, brown or golden ................................................................................... 7

6. Epihymenium producing abundant purplish-blue solution in KOH; epihymenium dark bluish purple; paraphyses abundantly branched at tips; apothecia brown to dark brown with rusty
red tinge; spores 12.5-15.5 X 5.5-8.5 Ám, isthmus 4.2-7 um; Calif., BC, Idaho .............. C. atrosanguinea
6. Epihymenium K-; epihymenium blue; isthmus very narrow (1.5 um); thallus gray; apothecial disks black, margin black; spores 11.2-12.6 X 5.5 Ám, isthmus 1.5 Ám (barely more than a septum); Minn, Mich. .......................................................................................................... C. parvula

7. Apothecial disks tan, pale; spore isthmus 7-11 um; thallus yellow-white; epihymenium K-; Spores 14-18 X 7-10 Ám; Colombia .................................................................. C. pallidior
7. Apothecial disks brown or darker; spore isthmus 3-5.5 um ................................................ 8

8. Epihymenium K+ violet or K+ brown turning violet ............................................................ 9
8. Epihymenium completely K- or K+ yellow ...................................................................... 14

9. Thallus with pseudocyphellae and/or isidia; radiating hyphae in upper exciple; spores with thickened end walls; spores 14-15.5 X 7-8.5 Ám, isthmus 4-5.5 Ám; tropical ...... C. neotropica
9. Thallus without pseudocyphellae and isidia ...................................................................... 10

10. Epihymenium K+ strong red turning purple with colored solution; no prothallus; apothecia 0.3-1.0 mm; paraphyses not swollen, frequently branched; spores with thick end walls, 12.5-17 X 7-10 Ám, isthmus 4-7 Ám; common N. Amer ......................................................... C. pollinii
10. Epihymenium K+ weak violet or K+ blue, no red color ................................................. 11

11. Epihymenium golden, K+ blue ...................................................................................... 12
11. Epihymenium gray, K+ weak violet ............................................................................... 13

12. Apothecial margin same color as disk; spores 14-15.5 X 7-8.5 Ám, isthmus 4-5.5 Ám; Brasil ............................................................................................................................ C. diducenda
12. Apothecial margin same color as thallus; spores 12.5-17 X 7-8.4 Ám, isthmus 3 um ............................................................................................................................. C. sp. Hawaii

13. Spores 11-12.5 X 5.5-7 Ám, isthmus 3-4 Ám; no prothallus; Sweden ............ C. suspiciosa
13. Spores 11-14 X 5.5-7 Ám, isthmus 5.5-7 Ám; black prothallus present; apothecia small (0.2-0.4mm); tropical, Caribbean, Paraguay ........................................................ C. floridana

14. Epihymenium K+ yellow; apothecia similar to Lecanora subfusca; small oval cells in upper exciple; spores 14-18 X 7-10 Ám, isthmus 4-7 Ám; Texas, Mexico [NOTE: This species has recently been found in additional localities in Mexico and often has a dull orange disk with K+ red  epihymenium (anthraquinones)] ............................................................................. C. diphasia
14. Epihymenium completely K- ......................................................................................... 15

15. Upper exciple with radiating hyphae .............................................................................. 16
15. Upper exciple with large oval cells ................................................................................ 17

16. Disks pruinose, apothecia 0.3-1.5 mm; paraph. tips hardly swollen; spores 11-14 X 5.5-7 Ám, isthmus 4-5.5 Ám; Common SE and E N. Am. ................................................. C. camptidia
16. Disks epruinose, dark brown, apothecia 0.2-0.6mm; spores 10-12.5 X 4-5.5 Ám, isthmus 4-5.5 Ám; Central N. Am. ............................................................................. C. brunneola

17. Soredia absent; thallus subsquamulose; spores 10-12.5 x 5.5-7 Ám, isthmus 4-5.5 Ám; North & South Dakota, Arizona, Texas ......................................................................... .C. dakotensis
17. Soredia present; thallus of dispersed low areoles; paraph. tips swollen; spores 10-14 X 5.5-7 Ám, isthmus 4-7 Ám; Rare .............................................................................. C. obscurella

18. Epihymenium K+ dark bluish-purple; epihymenium dark brownish violet; no algae in upper margin; spores 11-14 X 7-8.5 Ám, isthmus 3-4 Ám; Sweden ....................... C. atrocyanescens
18. Epihymenium K- or weakly K+ violet ......................................................................... 19

19. Thallus immersed or almost absent, not abundant ......................................................... 20
19. Thallus on surface, obvious, more abundant ................................................................. 21

20. Spore septa often poorly developed or with wide canal; epihymenium purplish brown; no algae in upper margin; thallus scant, white; rock HCL+; apothecial margin usually black; disks black, non-pruinose; spores 15.5-21 X 5.5-10 Ám, isthmus 0-1.5 Ám; western N. Am. ................ C. oblongula
20. Spore septa well developed, canal narrow; epihymenium hyaline to light brown; apothecia immersed in rock; spores 10-15.5 X 7-8.5 Ám, isthmus 3-4 Ám; Europe .................. C. alociza

21. Apothecia immersed in thallus at maturity; epihymenium K+ violet; spores 10-12.5 X 5.5-7 Ám, isthmus 3-7 Ám; Europe .................................................................................... C. chalybaea
21. Apothecia sessile at maturity ......................................................................................... 22

22. Apothecial margin with dense granules (disolving in KOH); thallus usually K+ yellow (atranorine); epihymenium usually K-, sometimes slightly K+ muddy violet ........................... 23
22. Apothecial margins without soluble granules; thallus K- ................................................. 26

23. Apothecial disks pale tan; apothecial margin thick, raised; spores 12.5-14 X 5.5-7 Ám, isthmus 4 Ám; Hawaii ....................................................................................................... C. albidella
23. Apothecial disks brown to dark brown ........................................................................ 24

24. Apothecial margin thick, raised, black; thallus thin, smooth; spores 12.5-14 X 7-8 Ám, isthmus 7 Ám; Andeman Isl. ................................................................................................. C. kurzii
24. Apothecial margins moderate to thin, flush, same color as thallus or dark brown ............ 25

25. Spores 14-15.5 X 7-8.5 Ám, isthmus 4-5.5 Ám; apothecia with only thalloid margin (light color); Rodriguez .................................................................................................... C. carneofusca
25. Spores 10-12.5 X 5.5-7 Ám, isthmus 4-7 Ám; apothecia usually with dark inner and pale outer thalloid margin; Caribbean .................................................................................. C. diplacia

26. Spores small and narrow (10-12.5 X 4-5.5 Ám); young apothecia often sunken in thallus .. 27
26. Spores larger (over 10 um long, over 7 Ám wide) all apothecia raised from thallus ............ 28

27. Thallus and apothecial margin K+ violet, 10% N+ violet (thalloidima green); thallus dark gray; epihymenium light brown; thallus K- (macro); areoles moderate; disks flat, dark brown to black; epihymenium weakly K+ violet; spores 10-12.5 X 4-5.5 Ám, isthmus 3-4 Ám; common .......... C. conversa
27. Thallus and apothecial margin K-, cN-; apothecial margin 10% N+ pale violet (lecidea green); thallus whitish gray; spores 10-14 X 4-5.5 Ám, isthmus 3-4 Ám ............................. C. sp China

28. Thallus all subsquamulose, partly stipitate areolate, thick; thalloid margin of apothecia usually thick and dominant; ....................................................................................................... 29
28. Thallus areolate, not stipitate or only partly so, sometimes thin ................................... 30

29. Thallus shiny olive brown, disks brown; epihymenium K+ violet; spores 14-17 X 7-8.5 Ám, isthmus 3-4 Ám; Calif. ..................................................................................... C. peliophylla
29. Thallus bluish-gray, usually mottled, areoles stipitate in places; cortex thick and uneven; algal in clumps and columns; disks black to dark brown; epihymenium weakly K+ violet; spores 14-18 X 7-10 Ám, isthmus 1.5-3.5 Ám; Rocky Mts. ................................................ C. albovariegata

30. No algae in upper amphithecium, internally brown; spores 14-16 X 7-8.5 Ám, isthmus 4-5.5 Ám; Antarctic ......................................................................................... C. austroshetlandica
30. Alage in upper amphithecium, internally not brown ......................................................... 31

31. Apothecial disks pale tan; no granules in margin; spores 12.5-14 X 7-8.5 Ám, isthmus 4 Ám; S Pacific ................................................................................................................ C. pallescens
31. Apothecial disks brown to dark brown .......................................................................... 32

32. Apothecia or margins white pruinose; prothallus black when present; epihymenium weakly K+ violet; spores 12.5-15.5 X 7-8.5 Ám, isthmus 3-3.5 Ám; mainly Europe, rare N. Am. (N. Mex.) ........................................................................................................................... C. variabilis
32. Apothecial margins and disks never pruinose ............................................................... 33

33. Spore isthmus 1.5-3 Ám; thallus smooth, cracked areolate, algal layer even, little or no necral layer on upper surface; spore isthmus very thin or sometimes absent; epihymenium weakly K+ violet; spores 14-15.5 X 7-8.5 Ám, isthmus 1.5-3 Ám; Common ........................... C. atroalba
33. Spore isthmus 3-5.5 Ám .............................................................................................. 34

34. Epihymenium and thallus K+ violet; spores 14-17 X 7-8.5 Ám; Europe ......... C. diphyodes
34. Epihymenium and thallus K-; spores 12.5-14 X 7-8.5 Ám, isthmus 3 Ám; Bear Isl. ..... C. ursina


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