Observation 92893: Bacidia De Not.

When: 2012-04-15

Collection location: Parque de Monsanto, Lisboa, Portugal [Click for map]

Who: zaca

No specimen available

Growing in the bark of a young tree. Some features of this specimen are:
- Thallus crustose, continuous, smooth, areolate/ rimose; greyish;
- Prothallus present as a thin black line;
- Apothecia round up to 1 mm; blackish; some of the aphothecia covered with a pruína; margin almost excluded in bigger apothecia;
- Asci clavate (presumably) with 8 acicular, hyaline, and many-septate spores with the following average dimensions: Me = 55.1 × 4 µm ; Qe = 13.9 (N=20);
- Paraphysis with hoods of brown pigment;
- Chemical reactions on thallus: all negative.
These features fit well in the description of Bacidia heterochroa given in CNALH, according to which this is a widespread species. Maybe there are other similar species, but I did’nt find a good key for this genus in Europe.


Chemical reactions;

Proposed Names

31% (2)
Used references: CNALH
Based on microscopic features
Based on chemical features
58% (1)
Recognized by sight

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= Observer’s choice
= Current consensus


Add Comment
I’m not sure
By: Jason Hollinger (jason)
2012-04-18 16:57:54 CDT (-0400)

In a case like this where the group is poorly known, it might be best to propose a name if you can find one that matches well. Authors doing a revision will know to check reports of that name if there are similar confusing species. It may help them prioritize work or search for interesting material.

In a case, on the other hand, where the species are well known, but we just don’t have sufficient experience to distinguish them reliably yet, then I think it might be best to stick to genus. No lichenologists are likely to come around soon to revise reports of such species.

Your call. In either case, though, I think all would agree: low confidence value is appropriate.

Yes, it is!
By: zaca
2012-04-18 15:54:14 CDT (-0400)

Maybe is better to stay at the genus level.

Extremely difficult group
By: Jason Hollinger (jason)
2012-04-18 13:26:31 CDT (-0400)

Bacidia and Bacidina with acicular spores are particularly difficult to distinguish. The key in the British flora requires all sorts of microscopic details: color of epihymenium and hypothecium in K, fine structure of tip of ascus when stained in K/I, size and shape of conidia, size and shape of paraphyses. The group has been well-studied in Scandanavia by Ekman, but I doubt the Iberian Peninsula has received as much attention.