Genus Cercospora in Thailand: Taxonomy and Phylogeny (with a ...

Key to the treated species in Thailand,
arranged by host family
Acanthaceae
1. Stromata lacking or rudimentary; conidiophores
relatively short, 16–60 × 3–6.5 µm,
geniculate; on Andrographis ........................
...................................C. andrographidicola
1. Stromata small, 20–24 μm diam.; conidiophores
long, 85–209 × 3–4 μm, slightly
geniculate near the apex; on Barleria .........
.............................................. C. barleriicola
Adiantaceae
A single species, on Doryopteris ...................
..............................................C. adiantigena
Amaranthaceae
1. Caespituli hypohyllous; stromata often
lacking, if present, small, up to 8 μm diam.;
conidiophores up to 5 in loose fascicles,
long, 90.5–192 × 3–4 μm; conidia acicular,
8–316 × 3–4 μm, 10–22-septate; on Iresine
and Celosia ............. Cercospora canescens
1. Caespituli amphigenous ............................. 2
2. Conidiophores up to 13 in moderately dense
fascicles, 34–85 × 2.5–5 μm; conidia
acicular, 12–67 × 2.5–3.5 μm, 4–7-septate;
on Celosia....................Cercospora celosiae
2. Stromata small, 12–26 μm diam.; conidiophores
5–9 in loose and divergent fascicles,
47–125 × 3–5 μm; conidia narrowly obclavate
to subacicular, 29–168.5 × 2.5–3.5 μm,
2–12-septate; on Ricinus ..............................
.................................... Cercospora ricinella
Apocynaceae
A single species, on Pentalino .........................
.................................. Cercospora peregrina
Arecaceae
A single species, on Areca ...............................
.............................Cercospora arecacearum
Asteraceae
1. Caespituli hypophyllous.............................2
Plant Pathology & Quarantine
1. Caespituli amphigenous ............................. 4
2. Conidiophores sometimes branched, 55–181
× 4–5.5 μm; on Artemisia.............................
................................. Cercospora artemisiae
2. Conidiophores unbranched......................... 3
3. Conidiophores 79–184 × 3–5 μm, geniculate;
conidia 120–215 × 3–4 μm, narrowly
obclavate to acicular, 8–20-septate, obconically
truncate at the base; on Helianthus
............................ Cercospora helianthicola
3. Conidiophores 25–102 × 25–4 μm, not
geniculate; conidia 46–87 × 2.5–3 μm,
acicular, 7–10-septate, truncate at the base;
on Dahlia..................Cercospora dahliicola
4. On Zinnia ................................................... 5
4. On other hosts ............................................ 6
5. Conidiophores unbranched, 54–100 × 2.5–5
μm; conidia 24.5–93.5 × 2.5–3.5 μm,
filiform to narrowly obclavate, 7–18-septate;
on Zinnia elegans .....Cercospora zinniicola
5. Conidiophores sometimes branched, 40–152
× 3–5.5 μm; conidia 24–175 × 2–3.5 μm,
narrowly obclavate to subacicular, 4–13septate;
on Zinnia grandiflora......................
...................................... Cercospora zinniae
6. Conidiophores not geniculate or rarely
geniculate, 32.5–220 × 3–8 μm; conidia 45–
196 × 1.5–3 μm, acicular, 13–19-septate,
truncate at the base; on Cynara....................
..................................... Cercospora cynarae
6. Conidiophores distinctly geniculate........... 7
7. Conidia obclavate or subacicular ............... 8
7. Conidia acicular ......................................... 9
8. Conidia obclavate, 80–96 × 3.5–4 μm; on
Conyza...................Cercospora nilghirensis
8. Conidia narrowly obclavate to subacicular,
60–198 × 2–4 μm; on Gerbera.....................
....................................Cercospora gerberae
9. Conidia truncate at the base, 23–190 × 2–4
μm, 3–10-septate; on Chrysanthemum
............................Cercospora chrysanthemi
9. Conidia obconically truncate at the base, 36-
182 × 3–6.5 μm, 7–13-septate; on Lactuca
........................Cercospora lactucae-sativae
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