PART 1

Afro-montagnard Centre-oriental: env. du km 42 de la route Bukavu-Walikale, alt. env. 2300 m,
épiphylle sur Connarus longestipitatus, Lambinon 71/1178 (LG, holotype, not seen).
Thelenella sp. Buck 18291A
Although known only from a small collection from Puerto Rico, this species is included as it extends the
limits of Thelenella. The ascospores are transversely 3-septate and the thallus is scanty but in other respects
it seems to be a typical Thelenella. The ascospores although small overlap the lower end of the ranges of
several muriform-spored species.
PUERTO RICO. Distr. Ponce: Caribbean National Forest, Toro Negro Division, along Hwy. 143 at Km 20.5,
ca. 100 m, on roadside pebble, 4 Nov 1990, Buck 18291A (NY).
TRICHOTHELIALES
TRICHOTHELIACEAE (Müll. Arg.) Bitter & Schilling
Since my brush with this family in my student days I have tended to avoid it being aware of the problems
involved with defining species. Recently it has received considerable attention. A family treatment for the
Guianas (Aptroot & Sipman, Flora of the Guianas, Series E, fasc. 2, 1993), saxicolous Southern Hemisphere
taxa (McCarthy, Biblioth. Lichenol. 52, 1992), Clathroporina (McCarthy, Lichenologist 27: 321-350. 1995) and
a revision of the genera (Hafellner & Kalb, Biblioth. Lichenol. 57: 161-186. 1995).
The first, the treatment for the Guianas, is rather unfortunate. For historical reasons and differing
approaches by the two authors, this is the kind of publication that gives a bad name to mycological αtaxonomists
struggling to deal with biodiversity before it is gone. It leaves us open to criticism (and denial of
funding) by those employing more sophisticated techniques. Three "species" concepts for ascospore variation
are used in the work without adequate warning or explanation. Following Santesson (1952) Sipman divided
foliicolous Porina into very narrowly defined species. In contrast Aptroot used a very broad concept for the
corticolous species, with what I would consider an unacceptably large amount of variation. A third treatment of
ascospore variation is found in Trichothelium where a distinct morphotype is assigned to the varietal level. I
think that as α-taxonomists we have an obligation to be consistent in our species concepts within a group or, if
not, then to provide some "hard" evidence as to why not. The treatment is also flawed in more obvious ways,
types of taxa described from the Guianas have not been studied and names have been used with little logic
(see criticisms by McCarthy, 1995). Such an interesting and complex family deserves better than this hasty
attempt.
McCarthy has provided two good, well illustrated α-taxonomic revisions. As will be seen below I do not
agree with him in all details (mostly in regard to recognition of North American populations which consistently
differ from his broader concepts). Thus I find Aptroot's comment in his review of McCarthy (1992) (Bryologist
97: 467. 1994) most amusing: "However, the species concept applied is rather narrow and some specimens
seem to represent transitional forms." I suspect that McCarthy's approach may well represent the mean
between the lumper and the splitter and therefore be the most useful to the general lichenologist trying to
name a specimen.
For those who dislike change, the paper by Hafellner and Kalb is most unfortunate, not only in itself, but
worse it has encouraged me to go even further in rearranging the Trichotheliaceae. They used the
pigmentation of the ascomatal wall to divide Porina s. lat. into Porina and Pseudosagedia. These groups have
been long recognized with varying degrees of clarity but mostly nomenclatural problems have led to the
retention of a broad Porina. Hafellner and Kalb have cut the Gordian Knot. Below I have taken a different
approach that essentially raises to the generic level the major groups recognized by Santesson (1952), uniting
the P. nitidula group (Pseudosagedia) with Trichothelium, removing the P. phyllogena group to Strigula and
adding a redefined Clathroporina. Amazing as it seems, this does not require the description of any new
genera.
Looking first at the taxa with blackish ascomata containing the pigment Pseudosagedia-violet, found in
both Pseudosagedia and Trichothelium, the question is "Are setose ascomata a generic character?". I do not
believe so. Hafellner and Kalb admitted there is an intermediate species with "bumps" on the ascomata (I
commend their honesty, I wouldn't have known). The tendency to develop ascomatal appendages in
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