Xylariaceae: Materials and Methods


The present study is based upon material collected mostly by the authors in different departments of southwestern France, and kept in their private herbaria. Abbreviations FC, JF, JFM, refer to the initials of the authors, respectively Françoise Candoussau, Jacques Fournier and Jean François Magni. All problematic identifications were made or confirmed by Professor J. D. Rogers.


Descriptions are based on the observations made on the collections listed under "specimens examined".

Microscopic observations were made in water for studying ascospore morphology, in Melzer's reagent* for testing the amyloidity of apical ring, in aqueous Congo Red, Blue Black Waterman ink or Phloxine for measurements of ascal stipes, in 10% KOH for testing the dehiscence of perispore.

Measurements of ascospores were taken in water at 1000x magnification on samples of 25 ascospores for each specimen, excluding aberrant and immature ascospores. For each species  the extreme values are given and the mean value (M) is given in brackets for Hypoxylon.

KOH-extractable pigments (Hypoxylon, Daldinia) are obtained by placing a fragment of stroma in a drop of 10% KOH on a microscope slide. The slide is placed on a sheet of white paper and extracted pigments are observed rapidly, within one minute.

The colour names are used following Rayner (1970).

The conidiogenous structures are named following Ju & Rogers (1996).

The macrophotographs and microphotographs were taken with Olympus OM-2 cameras. The microphotographs of asci and ascospores were taken in lactic blue (cotton blue in lactic acid) for Hypoxylon. In other xylariaceous  genera where germ slit characters are highly diagnostic and often inconspicuous, ascospores were mounted in Polyvinylic alcohol dissolved in lactophenol** and photographs were taken after they have stayed at last two days in this medium.

*Iodine 0.5 g, potassium iodide 1.5 g, water 20ml, chloral hydrate 20 ml.

**Rhodoviol® 50 g, water 150 g, lactic acid 80 g, phenol 40g.