27 August 2010

Larch and Spruce Forest Toadstools

After another wet August, mushrooms and toadstools have started to appear early in many of our local woodlands and the mature spruce and larch plantations of the Neath and Afan valleys are currently putting on a good show. Sitka Spruce (a native of the pacific North-west forests of North America) and Japanese Larch dominate these forests and both support an interesting assemblage of toadstools that form intimate and essential associations with the roots of these trees (ectomycorrhiza). I’ve posted a few photographs here that were taken in the forests near Ton Mawr.
Larch forests are always worth looking at. For example, many people will be familiar with the slimy yellow Larch Bolete (Suillus greveillei), one of the more common species in Larch forests, but it’s also worth looking for the much less common Larch Knight (Tricholoma psammopus), shown below.

In the photograph, notice the pale tan colour of the cap and the rusty brown stippling on the stipe. More importantly, the stippling ends abruptly at the top of the stipe to leave a distinctive clear area. This is a good identification character. The gills are yellowish-brown with rusty coloured spots, but the spore-print is white.
There are lots of toadstools that form intimate associations with spruce and Sitka Spruce forests are really good places to look for these interesting fungi. One of the most common spruce forest species is the False Saffron Milk-cap (Lactarius deterrimus), which can occur in huge numbers in these plantations. See photograph below.

Less common is Tricholoma pessundatum (photograph below), a species with a distinctive ring of dark coloured dots on its slimy brownish cap, which also grows in large conspicuous groups.

Lastly, the Fruity Brittlegill (Russula quelettii) appears to be frequently associated with Sitka Spruce in our forests. It is very similar to the much rarer spruce forest species, Russula fuscorubroides . Both have dark reddish-purple caps and their stipes are flushed with the colour of red wine. Their spores are creamy coloured and their gills eventually turn creamy-yellow. The photograph below shows Russula quelettii.

These characters will help to distinguish these two from other, more common red-purple capped species. However, telling the two apart is more difficult and the popular guides are of little help. One helpul character is that Russula quelettii has olivaceous tints in its cap, which become more evident in older specimens or after the caps have been soaked in rain – see the photograph of rain-washed specimens below.

The cap of Russula fuscorubroides tends to remain dark purple-red in colour even as it ages and I think the colour is less easily washed out of its cap. Records of all these species are of interest and comments are always welcome.


Barry Stewart said...

It seems our conifer forests are much more valuable than they're often given credit for. It would be a very interesting exercise to compile assemblages from a variety of taxa and compare coniferous and broadleaved woodlands locally.

Anonymous said...

They are for certain things but are generally devoid of bird and animal life once the trees are beyond a certain age