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. Coloured granules present
beneath the stromatal surface and between perithecia are described from a small
amount of interperithecial tissue observed in water under a magnification of
400. These granules appear as aggregated small amorphous particles. When they
are observed with a dissecting microscope, their true colour is often
masked
by the dark stromatal tissue, particularly when they are light-coloured,.
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.
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