An online resource based on the award-winning nature guide


Lady Fern Spores Maturing

Ferns are non-flowering plants which reproduce by spores, not seeds, and have a vascular system that transports fluids (unlike mosses, algae and liverworts).  Spores are typically located inside a capsule, or sporangium.  In many species of ferns, clusters of sporangia, called sori, are borne on the underside or margins of their fronds.  Often an indusium, or protective flap of tissue, covers each sorus, protecting the developing sporangia.  If you like to be able to give a fern a name, you will find that the shapes and arrangement of sori are a valuable identification tool.

Northern Lady Fern, Athyrium filix-femina, is a fairly common fern found in moist woods, swamps, thickets and fields.  It appears quite lacy and often grows in a somewhat circular cluster.  There are two distinguishing characteristics which are particularly helpful in recognizing Lady Fern.  One is its eyebrow-shaped sori.  If you look on the underside of a spore-bearing frond you will find that each sori is slighted curved, or arched, like an eyebrow.  The other diagnostic feature is the scattered thin, dark brown scales that are found on the stipe – the section of the fern’s stem between the ground and where the leafy frond begins.

This time of year, when the spores of many fern species are maturing, is a good time to learn the different ferns in the Northeast.  There are many excellent field guides to ferns.  One that you can easily tuck into your pocket is Lynne Levine’s Identifying Ferns the Easy Way.

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Giant Puffballs Maturing

10-17-18 giant puffball IMG_4353Puffballs are aptly named.  When their spores mature and the fruiting body splits open, rain drops, an animal passing by, or the wind cause puffs of spores to burst into the air,  dispersing them far and wide.  While puffballs vary tremendously in size, most would fit in your hand.  Exceptions include Giant Puffballs (Calvatia gigantea), one of which was collected in 1877 in New York state and measured 5 ½ inches by 4 ½ inches by 6 ¾  feet. The greatest recorded weight for a Giant Puffball is 44 pounds.

The production of spores takes place on basidia – club-like structures inside the fruiting body. The number of spores that these fungi produce is impressive. Mycologist Henry Buller estimated that a Giant Puffball measuring 16” x 11” x 8” (a fairly typical size) would contain more than 7 trillion spores.  (If you want to grow your own Giant Puffball so you can count the spores yourself, you can even purchase seeding spores online!)

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Stinkhorns Maturing

10-5-18 dog stinkhorn IMG_9973There are a group of fungi known as stinkhorns — aptly named, as their foul odor can be detected even by the human nose. All stinkhorns first appear as an “egg” which can be up to two inches high. When the eggs rupture, the appearance of the different species of fungi in this family (Phallaceae) can differ dramatically, but many have a phallic-like shape. At maturity, all stinkhorns produce an olive-green to olive-brown slimy substance that has a putrid smell (to humans), but is very appealing to many insects.  This slime is loaded with the fungi’s spores. Insects landing on a stinkhorn get their feet covered with the spore-laden slime while they are busy ingesting it.  Once the insects depart, the spores are dispersed far and wide.

Stinkhorns appear suddenly, and their growth can almost be observed, as they go from the egg stage to maturity with impressive speed. While these fungi are not poisonous, it is doubtful that having smelled them, anyone would desire to eat them.  (Photo:  Dog Stinkhorn aka Devil’s Dipstick, Mutinus caninus)

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Netted Stinkhorns Maturing


If you should detect an odor reminiscent of a decomposing carcass, it may well come from the spores of Netted Stinkhorn (Dictyophora duplicata) – the slimy, olive-green matter on the head, or top portion, of the fungus. When mature, the spores have a fetid odor which successfully lures insects, especially flies, to the fruiting body of this fungus. Some of the spores stick to the legs and mouth parts of the flies. Eventually the flies land on some real rotting material and the spores are transferred to a substrate they can grow on. Although it’s not too discernible in this photograph, Netted Stinkhorns derive their name from a fishnet-like veil, or skirt, below the head of the fungus.

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Dead Man’s Fingers

7-27-16 dead man's fingers IMG_6258

When it first appears above ground in the spring, the club or finger-shaped fruit of Dead Man’s Fingers (Xylaria polymorphaappears powdery white from the asexual spores that cover its surface. As it matures, it acquires a crusty, black surface. This is the sexual stage. The interior of the fruiting body of this fungus is white; just inside the outer surface is a blackened, dotted layer containing structures called perithecia which hold sacs of spores.

Dead Man’s Fingers, unlike most fungi, which release their spores in a few hours or days, releases its spores over months, or even years. It can have many separate fingers, sometimes fused together to resemble a hand.  Look for this fungus growing on hardwood stumps and logs, particularly American beech and maples.

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Horsetails & Scouring Rushes

5-20-16  equisetum044Horsetails and Scouring Rushes are in a primitive genus (Equisetum) of non-flowering plants.  Most of their stems are hollow and have distinct nodes, or swollen areas, where branches are sometimes attached.  Both stems and branches have vertical ridges and grooves.  Silica, embedded in the ridge tissue, led to the stems being used to scour pans as well as an abrasive for burnishing brass and finishing violins.

Equisetum leaves are barely recognizable as leaves – these pointed structures fuse into small sheaths surrounding each node.  A spore-bearing cone forms at the tip of the fertile stems.  If you look closely you will see that hexagonal plates (modified leaves) cover the surface of the cone.  Underneath these plates are the sporangia, in which spores are produced.  Upon maturation of the cone, the sporangia expand, split open and release their spores. (photo: Variegated Scouring Rush,Equisetum variegatum )

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Common Polypody Spores Dispersing

10-27-15 rock polypody 057Common polypody (Polypodium virginianum), also called Rock Cap Fern, is a perennial plant found most often growing on rock surfaces usually in moist, shady woods. Being a fern, Common Polypody reproduces by spores. Structures that produce and contain spores (sporangia) are found on the undersides of the fertile frond leaflets. The sporangia form round clusters called sori. The sori of Common Polypody are orange-brown when mature and lack the protective covering (indusium) that some other fern species have. At this time of year, the mature spores are being dispersed by the wind.

The ability of Common Polypody to tolerate extreme desiccation (the leaves roll up when moisture isn’t as available, and resume their normal state when moist conditions return) means it is well adapted to the extreme moisture fluctuations of rock surfaces. Its evergreen fronds are consumed in the winter by Ruffed Grouse, Wild Turkey, and White-tailed Deer.

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