Fungus Fact Friday

Tagged: basidio

#045: Mushroom Morphology: Sequestrate Fungi 3

Fungus Fact

#045: Mushroom Morphology: Sequestrate Fungi

The sequestrate fungi* are an unnatural grouping of mushroom-forming basidiomycetes that have adapted to life in desert areas by keeping developing spores inside the fruiting body. Because of this they are included among the gasteroid fungi.  Like the other gasteromycetes, sequestrate fungi cannot form ballistospores (see FFF#013), and cannot forcibly discharge their spores.  Sequestrate fungi have a stipe and a cap-like head, similar to toadstools.  However, the head never fully opens and the spore-bearing surface remains enclosed by the cap.  The gleba (fertile tissue) does not develop regular gills or pores.  Instead, the gleba forms irregular pockets that are sometimes gill-like in appearance.  This is a highly diverse group of fungi, so there are many variations on this basic structure.  Some sequestrate fungi partially open their caps, while others never do.  Some have reduced stipes and are barely held above the ground.

#044: Mushroom Morphology: Earthstars 1

Fungus Fact

#044: Mushroom Morphology: Earthstars

In celebration of Independence Day, I will be discussing the festively-shaped earthstars. Earthstars are characterized by a puffball-like sphere surrounded by a star-shaped base.  The earthstars all have a three-layered peridium (the surface that covers the developing spore tissue).  At maturity, the two outer layers split into rays and peel back to form the star-shaped base.  The endoperidium (interior layer) then develops an ostiole (pore) ringed by a peristome through which spores are discharged.  Earthstars are included in the gastromycetes, which all form their spores internally and cannot forcibly discharge their spores.  Instead, like the puffballs, spores of earthstars are forced out of the pore when raindrops land on the endoperidium.  All earthstars have capillatum, a network of cells designed to help spores move to the pore when a raindrop strikes the mushroom.  If you cut open an earthstar you will find that it looks nothing like the interior of...

#043: Mushroom Morphology: Bird’s Nest Fungi 2

Fungus Fact

#043: Mushroom Morphology: Bird’s Nest Fungi

These small (< 1.5cm) fungi are easily recognizable by their striking resemblance to a bird’s nest with eggs inside. The “eggs” are actually spore-containing sacks called peridioles.  As in the other gasteromycetes, the bird’s nest fungi produce spores internally and have lost the ability to forcibly discharge their spores.  To overcome this obstacle, the bird’s nest fungi developed their unique morphology to act as a splash cup.  The basic splash cup mechanism works as follows: a raindrop falls into the cup, which propels one of the peridioles (“eggs”) out of the cup.  The next challenge for the bird’s nest fungi is to stick to whatever they land on.  These fungi have evolved two different mechanisms in order to accomplish this.  Fungi in the genera Mycocalia, Nidula, and Nidularia have peridioles that are covered in sticky mucilage, which allows them to adhere to surfaces on contact.  Fungi in the genera Crucibulum...

#042: Mushroom Morphology: Earthballs 2

Fungus Fact

#042: Mushroom Morphology: Earthballs

This group of mushrooms goes by a variety of common names, including “earthballs,” “earth balls,” and “false puffballs.” Additionally, all of these mushrooms belong to the family Sclerodermataceae and could casually be referred to as “sclerodermas.”*  Using these terms to distinguish earthballs from puffballs is a fairly recent development, so many earthballs are still commonly called puffballs.  Visually, immature earth balls can look similar to puffballs.  If you are collecting puffballs to eat, make sure you know how to tell the difference between true puffballs and the usually poisonous earthballs.  The main difference between earthballs and puffballs is that, unlike the puffballs, earthballs do not release their spores through a regular pore.  Instead, the peridium (outer layer) cracks and tears irregularly.  Like all gasteromycetes (fungi whose spores mature internally), earthballs have lost the ability to forcibly discharge their spores.  The spores mature in the center of the earthball, enclosed by...

#041: Mushroom Morphology: Puffballs 5

Fungus Fact

#041: Mushroom Morphology: Puffballs

The puffball is probably the second most familiar mushroom morphology. Many people can remember finding one of these as a child and giving in to the uncontrollable desire to kick the ball-shaped mushroom.  Anyone who has tried this knows that your efforts are rewarded with a fabulous puff of spores.  This puff is not just for the amusement of small children but is actually a rather ingenious spore dispersal mechanism.  Puffballs are gasteroid fungi, meaning that spores develop inside the mushroom.  All gasteroid fungi have lost the ability to forcibly discharge their spores, so they have to come up with other ways to release their spores.  Puffballs achieve this by puffing their spores out of small openings.  When the spores are mature a small opening (or a few small openings) called an ostiole develops on the surface of the mushroom.  When a raindrop (or an animal’s/ someone’s foot) lands on...

#040: Mushroom Morphology: Stinkhorns 2

Fungus Fact

#040: Mushroom Morphology: Stinkhorns

As the name suggests, this group is made up of the most pungent fungi. The defining characteristic of this group is that they all produce a dark, smelly slime that carries their spores.  This slime smells like rotting flesh for the express purpose of attracting flies and beetles.  The insects walk around in the spore slime and then fly away, carrying some of the mushroom’s spores on their legs.  After visiting a stinkhorn, the insects either land on real rotting material or on another stinkhorn.  In the first case, the rotting material serves as a substrate on which the spores can grow.  When the insect lands on another stinkhorn, this allows for cross-fertilization (much like insect pollination of flowers).  The other factor that all stinkhorns have in common is that they have a button stage.  All stinkhorns form a small, white, oval-shaped structure, or “egg” that contains the basic form...

#039: Mushroom Morphology: Crust Fungi 1

Fungus Fact

#039: Mushroom Morphology: Crust Fungi

This is a broad group of fungi that includes all basidiomycete mushrooms with an exposed spore surface that is smooth or mostly smooth. This group excludes all mushrooms that may be placed into the other morphological groups that I have described previously as well as all lichenized fungi.  For example, many chanterelles and corals have a mostly smooth hymenium but are not included in the crust fungi.  There are also a number of ascomycetes that fit this description, although they are usually not included at all in field guides.  These ascos tend to have small dots or pimples where the spores are released, whereas crust fungi do not have such a distinction.  Crust-like ascos also tend to be harder than their basidiomycete counterparts, making microscopic examination somewhat difficult.

#038: Mushroom Morphology: Corals and Clubs 1

Fungus Fact

#038: Mushroom Morphology: Corals and Clubs

Most mushroom-forming Orders of fungi has evolved a coral or club morphology. To simplify things, I am using “Corals and Clubs” to refer to only clavarioid (coral-like) mushrooms in the Phylum Basidiomycota.  For clavarioid mushrooms in the Phylum Ascomycota, see FFF#036 (Earth Tongues) and FFF#037 (Earth Tongue Look-Alikes).  Unlike the earth tongues and look-alikes, the corals and clubs produce spores externally on basidia (see FFF#012 and #013 for more on basidia and asci).  If you have a microscope available, checking to see how your mushroom produces its spores can help eliminate some possibilities.

#031: Mushroom Morphology: Toothed Fungi 0

Fungus Fact

#031: Mushroom Morphology: Toothed Fungi

As you might suspect, toothed fungi are defined by a hymenium (spore surface) that consists of spines or teeth. On larger mushrooms this ends up looking something like a bunch of hedgehog quills stuck onto the bottom of a mushroom.  These teeth are always oriented straight down, perpendicular to the ground.  They are also always tapered to a point.  These two characteristics ensure that falling spores do not land on the spines as they fall.  Aside from these two characteristics, the toothed fungi can form a variety of different shapes.  One of the most commonly eaten toothed fungi, Hydnum repandum (commonly known as the “Hedgehog Mushroom”), has a pileus and central stipe that is reminiscent of a classic “mushroom” or toadstool.  Others, like Steccherinum ochraceum, lie flat against their substrate (resupinate) and produce small teeth.  Sometimes resupinate fungi make teeth that are little more than bumps on their hymenium.  Some...

#030: Mushroom Morphology: Polypores 4

Fungus Fact

#030: Mushroom Morphology: Polypores

One of the most commonly encountered mushroom morphologies is the polypore. Polypores are distinguished by a hymenium (spore-bearing surface) consisting of many, small pores.  Unlike in boletes, the pore surface of the polypores cannot be easily separated from the rest of the mushroom.  Polypores are a highly diverse group of mushrooms that come in a variety of shapes and sizes.  The polypores you are most likely to encounter, especially during the winter, are tough to woody mushrooms that can last throughout the winter.  Of these, the most common are the Turkey Tail (Trametes versicolor) and Trichaptum biforme.  Both of these are medium-sized wood decomposers often found covering fallen logs or stumps.  The tough fruiting bodies are annual, but can last for a year or more.  Other polypores that last through the winter produce large, woody conks on the side of living trees or fallen logs.  These mushrooms are perennial and...