Fungi in search of a good home

 Some mushrooms like soil, others look for wood. But not just any wood; it has to be the right kind, the right age, even the right location. But how do they find it, in a broken environment? For example, in a forest where there are scattered logs, some conifers, some deciduous, some green, some old and dry, some exposed, many hidden under a thick coating of moss. And the mushrooms which grow on these logs drop their spores vertically from gills or pores on the underside, sometimes barely millimetres away from the wood; how, then, do they manage to find a good home on the right sort of log many metres away?

Rusty gilled polypore,Gloeophyllum saepiarium, almost flat on the log.

Rusty gills on the end of a log; here the spores have a better chance, it seems.

Dyer's polypore, Phaeolus schweinitzii, on the ground under dead wood.

The spores are formed in the gills or pores; when they are ready, they are expelled into the space between the gills and gravity pulls them down. And then? 

Once the spore has fallen below the bottom edge of the mushroom cap, and is clear of the gills, it strikes air that is not still. Even on what looks like a windless day, there are always slight breezes. While a human may not feel them, they are usually strong enough to be felt by a spore that is only about a hundredth of a millimetre long. These micro-breezes may pick up the spore and carry it higher into the air and away from the parent mushroom. The spore may come to rest a metre or a kilometre or even further away from the mushroom. (AustralianFungi)

And this helps, too: 

Here we show that evaporative cooling of the air surrounding the pileus (the cap) creates convective airflows capable of carrying spores at speeds of centimeters per second. Convective cells can transport spores from gaps that may be only 1 cm high and lift spores 10 cm or more into the air. This work reveals how mushrooms tolerate and even benefit from crowding and explains their high water needs. (PNAS)

Crowded gilled mushrooms on a log.

Witches' butter forms its spores on the surface of the jelly. This allows the spores also to be carried by rain.

Witches' butter, Tremella mesenterica, on maple. It grows only on deciduous wood.

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A algunos hongos les gusta vivir en el suelo; otros buscan sitios en madera. Pero no cualquier madera: son exigentes, y tiene que ser la madera de su tipo favorito, de la edad adecuada, y hasta en el ambiente preferido. Pero, ¿cómo la van a encontrar, en un sitio variable? Por ejemplo, en un bosque donde hay troncos caídos, algunos coníferos, otros de hoja caduca, algunos todavía verdes, otros bien secos, algunos expuestos al aire y al sol, otros bajo una gruesa cobija de musgos. Y los hongos que crecen en estos troncos dejan caer sus esporas desde laminillas o poros en la superficie inferior, donde a veces apenas milímetros les separa de la madera. ¿Cómo es, entonces, que logran instalarse en otro sitio en un tronco adecuado tal vez a muchos metros de distancia de su origen?

Fotos:

1. Un políporo, Gloeophyllum saepiarium, creciendo casi pegado al tronco.
2. Otros de la misma especie en el extremo del tronco; aquí parece que las esporas tienen mejor posibilidad de viajar.
3. Un políporo, Phaeolus schweinitzii. Este está creciendo en el suelo debajo de madera muerta.

Las esporas se forman dentro de las laminillas o los poros; cuando están listos, se lanzan al espacio entre las laminillas y caen al aire libre. ¿Y entonces?

Una vez que la espora ha caído debajo del borde del sombrero y queda libre de las laminillas, se encuentra en aire inquieto. Aun en lo que parece un dia sin viento alguno, siempre hay una brisa ligera, que aunque no la puede sentir un humano, normalmente es suficientemente fuerte como para que la sienta una espora que mide apenas un centésimo de un milímetro. Estas mini-brisas pueden levantar la espora, llevarla para arriba y transportarla lejos del hongo original. La espora puede depositarse a un metro, un kilómetro, o aun más lejos del hongo. (AustralianFungi)

Y esto puede ser de ayuda también:

Aquí demonstramos que el enfriamiento por evaporación del aire que rodea el sombrero crea corrientes de aire por convección que son capaces de llevar las esporas a velocidades de varios centímetros por segundo. Zonas convectivas pueden transportar las esporas desde espacios que miden solamente 1 cm. verticalmente y levantarlas 10 cm. o más al aire. Este trabajo demuestra como es que los hongos toleran y hasta reciben beneficio por vivir apiñados; también explica su necesidad de una suficiencia de agua. (PNAS)

Foto:

    4. Hongos con laminillas creciendo amontonados en un tronco.

    5. La "mantequilla de brujas", Tremella mesenterica, forma sus esporas en la superficie de la masa gelatinosa. Esto permite que las esporas se dispersan con la lluvia. Estas estan creciendo en un tronco de arce. Vive únicamente en madera caducifolia.

No bird built these bird's nests.

 They look like birds' nests. But most of the "eggs" have flown.

A cluster of bird's nest fungi on a branch beside the Eve River. Probably Nidula sp.

The "eggs" are spore cases. They lie in the bottom of the nest until a drop of rain dislodges them. Because of the shape of the cup, they can be shot out up to 2 metres from the source. There, they dry out and split apart, releasing the spores. 

Six of these nests are empty. It has been raining, and the spore cases (peridioles) are now settling in among the twigs in the duff around their tree. Two of the nests are still full.

I brought home a twig from Oyster Bay with a couple of bird's nest fungi, and turned the microscope on them.

The "eggs", tied up in string.

Some species have a sticky trailing thread, a funicular cord, attached to the peridiole. If that thread encounters a twig on its flight, the peridiole will swing around and wrap itself around the twig.(Wikipedia)

I don't know if these are the threads Wikipedia is talking about. I haven't noticed them on other bird's nest fungi, but then I haven't looked at the others under the 'scope. Next ones I find, I will.

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Parecen nidos de pájaro. Pero los huevos ya volaron.

Estos son hongos nido creciendo en una rama cerca del río Eve, probablemente perteneciente al género Nidula. Los dichos "huevos" son cuerpos fructíferos donde se desarrolan las esporas. Esperan en el fondo del nido hasta que una gota de lluvia, cayendo dentro del nido, les lanza al aire. Pueden llegar hasta a dos metros del sito de origen. Allí se secan y se abren, dejando las esporas en libertad.

Seis de estos niditos ya han esparcido sus esporas en las recientes lluvias, y los peridiolos (así se llaman los "huevos') ya estarán escondidos entre las ramitas caídas en el suelo. Dos esperan una próxima gota de agua.

Me traje una ramita con hongos nido de Oyster Bay y los examiné bajo el microscopio.

Foto: un nido con sus peridiolos, que parecen estar enredados con hilo.

Dice Wikipedia: "Algunas especies tienen un hilo pegajoso que se extiende desde el periodolo, una cuerda funicular. Si ese hilo se encuentra con una rama al volar, el periodolo se dará vuelta alrededor de la rama,"

No sé si estos hilos en la foto son los de que habla Wikipedia. No los he visto en otros hongos nido, pero no los he mirado con el microscopio, solamente con lente de mano o la cámara. Lo haré en el futuro.

Snow white hair

Growing on a fallen alder, I found a colony of fuzzy white polypore mushrooms.

The largest of the group, under 3 inches across. Before the snow fell and froze solid, slugs had been feasting on the fur.

The underside. This mushroom has large pores. Normally, the spores would develop inside these pores, then fall directly to the ground beneath. Now that the tree is fallen, the spores are trapped inside the mushroom. A few may escape to fall on the trunk.

 A few of the babies. These are all under half an inch wide, and as white as the snow beneath.

These are probably Trametes hirsuta. ("Hirsuta" means "hairy". Good name. They are hairy, although the hair is arranged in stiff peaks, as if someone used too much hair gel.)

These mushrooms grow mostly on dead hardwood, and slowly return it to the soil to nourish the next generation.

Somehow, I'm never tempted to taste a bracket mushroom, or wonder about its edibility (although some are edible, I know), but mushroom guides routinely mention this. On the E-Flora page about T. hirsuta, under the "Edibility" heading, a contributor has commented, "Too tough." Looks about right. Too hairy, besides.

Soggy

I can't resist stepping on ripe puffballs. Doing my part to help with spore dispersal, I say, to excuse my childishness. But this week in the Tyee Spit puffball patch, the puffballs wouldn't puff; they squished and oozed instead.

Cave full of powder, too damp to fly.

Call them oozeballs this year.

The puffball has a unique spore dispersal strategy.  Within the spongy interior, the spores are produced by the trillions.  Eventually, the puffball dries and hardens to the point where it is a papery sac filled with trillions of spores.  When an animal comes along and steps on or bites into the puffball the spores are ejected forcibly.  For small puffballs this can even be accomplished by the impact of falling raindrops. (Field notes)

Anything that grows in the Pacific Northwest has to be able to cope with rain, and puffballs can use it even to get their flying spores airborne. Here's a gif of raindrops causing puffballs to puff.

Once spores are caught by the wind they can be carried very long distances. Spores of a wheat rust have been reported to have been dispersed 1,243 miles (2000 km) by the wind. (Fun Facts about Fungi)

But there can be too much of a good thing. This year's spores aren't going to go far from home.