the genus Coccocarpia (Peltigerales: Coccocarpiaceae) - Instituto ...

with numerous white, stellately arranged, 0.3–0.5 mm long rhizines attaching the apothecia
to the thallus. Ascospores globose, 4–5 µm diam. Pycnidia not observed.
Chemistry: No substances detected by TLC.
Notes: Until recently, this new taxon was not properly recognized, hence the epithet
neglecta, but considered to represent an extreme form of Coccocarpia domingensis,
another commonly foliicolous species with thin, linear lobes and isidia, However, the isidia
in C. domingensis are of a different nature, being cylindrical to somewhat flattened but
always elongated and erect rather than horizontal. Also, apothecia are much less common
in C. domingensis. Coccocarpia stellata is also similar but completely lacks isidia or
lobules. The three species can often be found side by side on the same leaves, especially
Citrus leaves in humid, warm conditions.
The isidia of Coccocarpia neglecta can be confused with secondary lobules but, for
example contrary to the phyllidia in C. microphyllina, clearly represent diaspores and thus
must be interpreted as isidia, Very similar isidia are known from C. pellita.
Distribution and Ecology: A common foliicolous species in exposed situations in
areas of wet tropical rainforest from sea level to 2000 m; also known from Ecuador
(reported as Coccocarpia domingensis in Lücking, Lich. Fol. Exs. 194).
Selected specimens examined: COSTA RICA. Heredia: La Selva Biological Station, Jun 1997, Lücking
97-989 (F); Jul 1997, Lücking 97-1358 (F). Limón: Finca Hamburg, Aug 1936, Dodge & Goerger 10271
(FH; as Coccocarpia domingensis). Forest along new tramline beyond bridge over Río Parismina on Finca
Siam, Jul 1936, Dodge & Goerger 9530 (FH; as C. tenuissima). Puntarenas: La Amistad International Park,
July 2002, Sipman 48039 (B, INB-3944635).
ECUADOR. Pichincha: Guajalito Biological Station, May 1996, Lücking 96-292 (F).
Coccocarpia palmicola (Spreng.) L. Arvidss. & D. Gall. Fig. 1C–D, 4A–H
Notes: This is the most common species in the genus, with a wide morphological and
ecological amplitude (ARVIDSSON 1983). Our observations both in the field and in the
laboratory confirm ARVIDSSON's statements that lowland forms tend to be more adnate and
often more narrow-lobed, while montane populations are usually loosely attached and
broad-lobed. We also observed that the lowland forms (Fig. 4A–D) mostly have blue-black
rhizines and rather compact, clavate isidia, while the montane populations (Fig. 4E–H)
feature white rhizines and irregularly elongate, often almost budding, cylindrical isidia.
Since intermediate forms exist, we follow ARVIDSSON's concept and keep all these forms
under a single species, but it will be interesting to study this intriguing variation with
statistical and molecular tools based on a large specimen sampling.
Selected specimens examined: COSTA RICA. Alajuela: Alto de La Palma de San Ramón, Jan 1930,
Brenes s.n. (FH; as Coccocarpia isidiophylla var. prolificans). Alto del Mondongo del San Ramon, Jan 1930,
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