Identification of the Larger Fungi. Roy Watling
9A). This same tissue may be thick or sparse to wanting, coloured or not. Such sections are often better than attempts at very thin sections unless very specialised techniques are used. There are few satisfactory thicknesses between the two extremes; the thick sections you can do and the very thin requiring expert techniques.
Larger illustration
5. Take out a small block of tissue T as indicated in the figure (fig. 1). Mount immediately and repeat as in 3. This will allow the outer layer of the cap to be more clearly seen (fig. 7A-C) and also the structure of the flesh (fig. 10). The latter may be composed of a mixture of filaments and ‘packets’ or ‘nests’ of rounded cells (i.e. heteromerous), or of filaments, only some of which may be inflated (i.e. homoiomerous); but when individual cells are swollen they never form distinct groups. By very similar techniques it is possible to show that the more woody fungi can have flesh composed of one of four types of cells (Corner, 1932): these types depend on whether distinctly thickened cells (plate 47) are present with the actively growing hyphae or not (pp. 140–150), whether hyphae are present which bind groups of hyphae together, etc. (plate 46).
6. Remove stem along line CD and cut out small blocks of tissue as indicated (U, V and W). Mount immediately and examine as in paragraph 3, for cystidia, etc. (see fig. 3).
Whilst all these sections are being cut and processed a second fruit-body, if available, should be set to drop spores; this is done by cutting off the cap from the stem and placing it either entirely or in part, and with gill-edges down, on a slide in a tin.
7. Z is a ‘scalp’ of a cap; a thin sliver from the cap is placed on a slide in a drop of water (modified with washing-up liquid, etc. as above). After placing a cover-slip over the tissue it is tapped gently; this will show if the cap is composed of globose to elliptic elements or if it is composed of strictly filamentous units (figs. 6A & B). Care must be taken not to reverse the section when transferring it to the mountant, either by turning the scalpel or by allowing the surface tension of the liquid to pull the section upside down. The construction of any veil fragments will also be seen in this mount, and if a loose covering of veil is present this should be removed before observation so that it does not obscure the fundamental structures.
8. Examine the stipe of the fruit-body used above under a low power or with a dissecting microscope in order to ascertain whether there are any remains of veil and/or vegetative mycelium. If found, mount immediately in the solution containing iodine mentioned above and examine.
Of course it is difficult to carry out the above system the first time and be successful in seeing everything, indeed in being able to cut all the sections 1–8. Practice makes perfect, so why not practise with a 1⁄4 lb of mushrooms from the grocer before the autumn season starts. In this way you will have overcome the difficulties without having to experiment with your collections.
| CHARACTERISTICS FOR THE IDENTIFICATION OF HIGHER FUNGI WITH CAPS | |||||
| Locality | G. Ref. | Date | |||
| Habitat notes | soil type | pH | |||
| vegetational community | |||||
| solitary; in troops or rings | |||||
| Draw or preferably paint exterior and vertical section of fruit-body | |||||
| MACROSCOPIC CHARACTERS | |||||
| CAP | |||||
| General characters: | |||||
| diameter | shape | consistency | |||
| colour: | when immature | when mature | |||
| when wet | when dry | ||||
| Surface | |||||
| dry, moist, greasy, viscid, glutinous, peeling easily or not, smooth, matt, polished, irregularly roughened, downy, velvety, scaly, shaggy | |||||
| Margin | |||||
| regular, wavy | incurved or not | ||||
| smooth, rough, furrowed | striate or not | ||||
| Veil, if present | |||||
| colour | abundance or scarcity | ||||
| distribution at margin, whether appendiculate or dentate | |||||
| consistency, whether filamentous, membranous | |||||
| GILLS, or pores or teeth etc. | |||||
| remote, free, adnate, adnexed, emarginate, subdecurrent, decurrent | |||||
| crowded or distant | distinctly formed or not | ||||
| shape | interveined or not | ||||
| easily separable from the cap-tissue or not | |||||
| consistency (whether brittle, pliable, fleshy or waxy) | |||||
| thickness | width | ||||
| colour: | when immature | at maturity | |||
| number of different lengths or number of layers | |||||
| obvious features of gill-edge, tube-edge, e.g. colour, consistency | |||||
| STEM | |||||
| central, eccentric or lacking | shape | ||||
| dimensions: length | thickness | ||||
| hollow or not | |||||
| colour: |
| ||||