The postman rings againPosted: 22/05/2013
I thought I would take the opportunity to clear my inbox and share the treasures with.
I was sent this photo of boletes collected from under oaks in Hagley Park in Christchurch. The characteristic features of these boletes are the finally cracking cap surface exposing the underlying flesh, the yellowish pore surface and upper stem and the reddish base to the stem.
I went back to the sender and asked if where the brown skin of the cap has cracked is the flesh underneath slightly pinkish or is it yellow? If you cut the stem lengthwise it should be reddish near the bottom, after a few minutes exposure to the air does the cut flesh turn bluish? His response was no to both questions. This does show the difficulty of identifying specimens that are past their prime. If we look at both characteristics in turn: The cracking of the cap is quite apparent but the exposure of the reddish underlying tissue is not reliable as it changes with the age. Also many of the description in fact say that the underlying tissue is only pinkish and usually only towards the margin of the cap. As these specimens look reasonably weather beaten and quite dry it is not surprising that the pinkish flesh is not obvious.
The second characteristic is the bluing of the bruised or cut flesh. While seeming a strong feature one description says “sometimes blueing when bruised” and “this reaction takes several seconds with the blueing never as intense”. Not a great character for beginners. If you look carefully at the tube surface of the two boletes in which this character can be seen you will see grey bruising on the pore surface where the bolete has been handled. In some species blue bruising can be greyish and/or be bluish initially then turn grey.
Given that I only have a photo my pick is that this is Xerocomus chrysenteron [red-cracked bolete]. The only other species which it could be is Xerocomus porosporus which I have only seen in Dunedin.
Gracie MacKinley found this large puffball in Greenhithe, Auckland. It is probably Calvatia craniiformis [brain puffball] however it would be difficult to identify as it is immature. You can tell this from the solid white flesh inside the puffball.
As the puffball matures the flesh will convert to spore producing cells. Each of these cells will produce four spores. Once the spores are developed they will dry out to become a powdery yellowish green mass inside the leathery shell of the puffball. Eventually the shell will break to release the spores to the wind. During the drying process the puffball becomes wrinkled like a human brain. The solid white flesh of the immature puffball of Calvatia craniiformis is edible.
Keelan Walker in Blenheim sent me these photos of a bolete under pines. I asked Keelan whether they were sticky on top or did it look like it could have been sticky because pine needle etc. have become firmly stuck to the cap? Did the stem look smooth or spotted with darker markings? When you cut through the flesh length-wise (cut it in two equal halves including the full length of the stem) does any of the cut flesh turn bluish or bluish-black?
Keelan responded “seems to be a sticky substance on the top and on the stem but I don’t notice any spots. When I cut it through the middle there is no blue/black colouring. There is a yellowish/sulphur type colouring tainting the flesh of the cap through”. All useful observations and indicate that this is Suillus granulatus [sticky-bun bolete].
Jan Nisbet photo, from the Whareroa Farm walk about 3.5 km north of Paekakariki, while not a fungus is topical at the moment.
This is a slime mould, Physarium cinereum, which is common at this time of the year on the blades of grass. Slime moulds live as free living organisms in the soil engulfing micro-organisms as a food source. When the reproductive urge takes hold they climb to a high place, in this case blades of grass, and convert, almost metamorphosis, into these rigid fungal like fruiting bodies. The fruitbodies will become hard, break and release spores to start the process again.
Ginelle Simoes left a message on my blog About page last night alerting me to mushrooms growing in the wood mulch under the pohutukawas at the intersection of Jervois Quay, Wakefield St and Taranaki St. Like any good mycologist I was down there at 9pm last night in the dark taking photos and collecting specimens. These were large white and brown, shaggy Chlorophyllum (Macrolepiota) rhacodes and smaller dark brown species of Agaricus. Chlorophyllum rhacodes is regularly eaten as are species of Agaricus (the mushrooms in the supermarket are a species of Agaricus).
Update 24 May 2013
Here is a closer view of the ‘double ring’ found in Chlorophyllum rhacodes as mentioned by Jerry in the correspondence below.