This week I found this fungus, which I believe be Hypoxylon rubiginosum "species complex", but I would like to hear some additional (expert) opinions.
In my opinion the fungus presented here is the same posted by Enrique Rubio (http://www.ascofrance.fr/search_forum/15884),
The fungus was found on dead twigs of Tabebuia sp., in Southeast Brazil.

Short Description:
Stroma dark brick-red to brown, 3 to 8 mm, sometime reaching 1 cm, with minute whitish dots (ostioles) below or at same level of the stromatal surface (Fig.1A-D); Ectal-excipulum textura prismatica (Fig.1H); Asci cylindrical up to 130 x 6-8 microns (Fig.1I-K); Ascopores periospores (Fig.1L-O) elliptical with on side flattened, 8.5-10 x 4-5 microns, with germ slit from end to end (Fig.1Q-S) and with almost inconspicous ring-like transverse ornamentation (Fig.1T).

Additional notes: This specimen reacted positively with MLZ (blue apical ring), without pre-treatment with KOH (Fig.1P). Orange pigments on paper with KOH 5% (Figs. 1E-F).

Any advise will be welcome.
Thank you very much.

Legend: A and B - superficial view of the stroma; C - transversal section of a stroma; D - laminar section of a stroma; E, F and G - pigments on KOH after 10 sec, 5 min, and 1:30 h, respectively; H - ectal-excipulum textura prismatica; I and J - asci on MLZ; K - young ascus on H2O; L, M, N and O - sheat release; P - blue apical ring in MLZ without pre-treatment with KOH; Q, R and S - germ slit; T - ring-like transverse ornamentation.

Jacques Fournier, 25-04-2015 14:36

Re : Hypoxylon rubiginosum??

Hi Dartanha,
Hypoxylon rubiginosum does not occur in tropics but it has many look-alikes. Based on the somewhat vinaceous tone of the stromata and the sigmoid germ slits I would go for H. fendleri Berk. ex Cooke but with some reservations.
Could you send it over at the following adress?

Jacques Fournier
Las Muros
F. 09420 Rimont

Thanks,
Jacques

Dartanha Soares, 27-04-2015 17:19

Re : Hypoxylon rubiginosum??

Hi Jacques,

Thank you very much for your comment.
I sent a private email to you.

Dartanha