Key to
sorediate and isidiate species of Caloplaca
By Clifford
Wetmore
March 2000
North American species in bold.
1. Growing on bark and wood and moss
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1. Growing on rock or soil
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13
2. Thallus obvious and gray
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3
2. Thallus shades of orange, sometimes
yellowish orange or immersed, or with orange soredia or isidia -------- 8
3. Thallus with isidia only
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4
3. Thallus with soredia
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6
4. Isidia coralloid
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C. lagunensis
4. Isidia granular or unbranched
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5
5. Without distinct thallus, dark gray
when present, isidia small, granular ------------------------------ C.
furfuracea
5. With distinct whitish gray continuous
thallus, isidia pale, simple ------------------------------------- C.
wrightii
6. Soredia dispersed, granular
--------------------------------------------------------------------- C.
chlorina
6. Soralia crateriform, soredia fine
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7. Apothecial disks orange
------------------------------------------------------------------------------ C.
ahtii
7. Apothecial disks brown
----------------------------------------------------------------------- C.
obscurella
8. With granules and isidia, sometimes
sorediate ------------------------------------ C. xanthostigmoidea
8. With soredia only
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9
9. Thallus subsquamulose on surface of
substrate ---------------------------------------- C. microphyllina
9. Thallus areolate or leprose or immersed
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10. Soredia light brownish orange
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11
10. Soredia yellowish orange or orange
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11. Thallus leprose, without corticate
parts ---------------------------------------------------- C. chrysodeta
11. Thallus areolate or continuous,
corticate ------------------------------------------------------------ C.
sp.
12. Thallus immersed, yellowish orange,
soralia delimited --------------------------- C. chrysophthalma
12. Thallus on surface, orange, soredia on
margins or thallus surface or scattered in clumps - C. citrina
13. Fine soredia present
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14
13. Fine soredia absent, with isidia,
papillae or phyllidia ------------------------------------------------------ 18
14. Soralia laminal, crateriform,
punctiform, eroding ----------------------------------------- C. cupulifera
14. Soralia marginal or erupting from
center of thallus, not crateriform -------------------------------- 15
15. Thallus with elongated lobes
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15. Thallus scant, leprose, areolate or
subsquamulose ------------------------------------------------------ 20
16. Soredia originating from center of
thallus laminally, greenish orange when fresh ----------------- C. cirrochroa
16. Soredia originating from tips of
lobes, same color as thallus ---------------------------------------- 17
17. Thallus moderate in diam. (5-20 mm or
more), lobes broad (0.5-1 mm) ---------------------- C. decipiens
17. Thallus small in diam. (1-2 mm), lobes
narrow (0.2-0.5 mm) ------------------------------------ C. stellata
18. Lobes strongly convex, cortex not paraplectenchymatous,
globose isidia present --------- C. verruculifera
18. Lobes flat at tips, cortex
paraplectenchymatous, papillae or phyllidia present -------------------- 18
19. Thallus with small laminal papillae, lobes
thin (87-101 µm) ---------------------------------- C. brouardii
19. Thallus with phyllidia on central
areoles, lobes thick (175-240 µm) ----------------------------- C. texana
20. Thallus entirely thick leprose,
margins slightly lobed, with raised ridges, on thick white cottony medulla,
soredia yellowish orange
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C. xantholyta
20. Thallus not thick leprose, margins not
lobed, without raised riges, without white cottony medulla (unless soredia are
brownish orange), soredia orange or brown
------------------------------------------------------ 21
21. Soredia diffuse, brownish, thallus not
areolate, soredia sometimes on cottony white medulla ---- C. chrysodeta
21. Soredia in distinct soralia, orange,
thallus areolate, never with white cottony medulla ----------- 22
22. Soredia mixed with granules (sometimes
coralloid) ------------------------------ C. xanthostigmoidea
22. Soredia only, no granules
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23
23. Thallus gray, soralia delimited in
center of areoles, soredia bright orange, only in high arctic ----------- C.
sp.
23. Thallus orange, soralia marginal or
scattered with no corticate areoles, temperate or arctic ----------- 24
24. Thallus with distinct corticate short
lobes --------------------------------------------------------------- 25
24. Thallus only slightly notched or no
corticate parts ----------------------------------------------------- 26
25. Lobes irregular, mixed with areoles,
strongly convex, soredia from lower surface, arctic ------- C. soropelta
25. Lobes radiating, only slightly convex,
no areoles, soredia from tips of lobes ----------------------- C. stellata
26. Thallus with notched areoles
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27
26. Thallus strictly areolate
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28
27. Areoles with scattered granular soredia
on margins and surface, no prothallus, not on littoral rocks
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C. pygmaea
27. Areoles with soredia mainly from
margins, sometimes spreading, granular, usually with yellow prothallus,
restricted to littoral rocks
--------------------------------------------------------------------------- C.
flavogranulosa
28. Thallus with convex slightly
irregularly lobed or notched areoles, corticate areoles predominate, always on
soil
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C. tominii
28. Thallus with flat to concave areoles,
soredia predominate, usually on rocks, occasionally on soil ---------------------------------------------------------------------------------------------------------------
C. citrina