Hello Forum,
at the end of september 2008 I found in addis abeba (ethiopia) a Xylaria.

Macroscopic features:
Stromata gregarious, unbranched, clavata narrow cylindric, 25-55 x 0,5-1 mm with sterile apices; stipe distinct, smooth, half of the clavata; subiculum sparseley setose, brown; perithecia , evident, globose, ostioles papillate

Microscopic features:
Ascus with 8 ascospores, 110-120 x 5,5-6,5 μm
Ascospores brown, germ slit straight, with hyalin appendage, elliptic to navicular with narrow ends, 10-11,5(13) x 4-4,8 μm (appendage: 1,5-2 x 1 μm)
In my opinion it is Xylaria gracillima. Could that be correct?

I used the following studies to determine the species:
DENNIS, R. W. G. (1961): Xylarioideae and Thamnomycetoideae of Congo. Bulletin du Jardin Botanique National de Belgique 31: 109-154.
DENNIS, R. W. G. (1962): Xylarioideae and Thamnomycetoideae. Flore Iconographique des Champignons du Congo. 11. Fasc.
HLADKI, A. I. & ROMERO, A. I. (2007): Primeras citas del género Xylaria (Ascomycota, Xylariaceae) para la república Argentina. Darwiniana 45(1): 28-44.
MARTIN, P. (1970): Studies in the Xylariaceae VIII: Xylaria and its allies. Journal of South African Botany 36: 73-138.
ROGERS, J. D. & CALLAN, B. E. & ROSSMAN, A. Y. & SAMUELS, G. J. (1988): Xylaria (Sphaeriales, Xylariaceae) from Cerro de la Neblina, Venezuela. Mycotaxon 31 (1): 103-153.
Thank you very much for your help!
Uwe