Ramble Report September 3 2015

Today's report was written by Dale Hoyt. The photos that appear in this blog are taken by Don Hunter; you can see all the photos Don took of today's Ramble here.

Twenty-three ramblers met at the Arbor at 8:30AM on an overcast, cool morning.

Today's reading: Dale read the entry for August Thirty-first from Donald Culross Peattie's Almanac for Moderns:

August, the aureate month, draws to its blazing close – a month of sun, if ever there was one. Gold in the grain on the round-backed hill fields. Gold in the wood sunflowers, and in the summer goldenrod waving plumes all through the woodlot, trooping down the meadow to the brookside, marching in the dust of the roadways. Gold in the wing of the wild canaries, dipping and twittering as they flit from weed to bush, as if invisible waves of air tossed them up and down. The orange and yellow clover butterflies seek out the thistle, and the giant sulphur swallowtails are in their final brood. The amber, chaff-filled dust gilds all the splendid sunsets in cloudless, burning skies. Long, long after the sun has set, the sun-drenched earth gives back its heat, radiates it to the dim stars; the moon gets up in gold; before it lifts behind the black fields to the east I take it for a rick fire, till it rises like an old gold coin, that thieves have clipped on one worn edge.

Today’s route:  Leaving the arbor, we made our way down through the Shade Garden, taking, first, the paved path for a bit, then taking the mulched path down to the Dunson Native Flora Garden.   We made our way through the Dunson garden and, after exiting at the lower entrance, we made our way out into the power line ROW.  We followed the White Trail in the ROW to the river then turned around and retraced our steps back to the parking lot.

Arbor: Our assembly area was littered with unripe acorns and we could hear more falling. But it was not the oak that was discarding its offspring – it was a rapacious gray squirrel apparently searching for a tasty protein snack. Weevil grubs infest many acorns at this time of year and squirrels will grab a nut and chew through the shell to eat the grub inside. How they recognize infested from uninfested acorns is anyone's guess; perhaps they smell different. A few of the discarded acorns were completely stripped of their shells and the nut meat had been nibbled all around before it was dropped to the ground. Were these being tested for edibility? This is the beauty of nature – the closer you look the more questions you get.

Nibbled and eaten oak acorns

Shade Garden: Today turned out to be a mushroom day. (After all, our motto is "Seeking What We Find.") 

It's probably best to start with a primer about the types of mushrooms we discovered today, restricting our focus on ordinary "toadstool" type mushrooms. These are mushrooms that have a stalk and a cap perched on top of the stalk. If you look on the lower surface of the cap you will discover that there are two very different appearing types of mushrooms. One type has thin sheets or membranes that hang down from the underside of the cap. These are called gills and they radiate out from the center of the cap, where it is attached to the stalk. Such mushrooms are called gilled mushrooms. The other common type of mushroom that we saw today has a spongy cap with no gills. Closer examination of the cap's lower surface reveals a large number of densely packed small holes. Each hole is the end of a tiny tube. The entire lower side of the cap is made of these tubes tightly packed together, like a box of drinking straws. If you squeeze such a cap you'll discover that it feels like a very dense sponge. These mushrooms are called boletes (pl.; sing., bolete; pronounced: bow-leet). 

Both these types of mushrooms belong to the phylum Basidiomycota. They reproduce by spores called basidiospores that are produced by special cells, called basidia. The basidia are found on the gills of the gilled mushrooms and on the inner tube walls that make up the bolete cap. The spores are popped off the basidia into the space between the gills, or into the hollow cavity of the pores of the boletes. In both cases they then fall into the open where they can be carried away by the gentlest of breezes. 

If the spores land in a suitable location they will germinate and produce fine thread that is the beginning of a new fungal organism. This fine thread elongates and branches, forming a network of fine threads called a mycelium. The mycelium makes up the body of the fungus and continues to grow through its substrate, breaking down and absorbing organic material as it increases in size. When the mycelia of many basidiomycetes encounter the roots of a tree or other vascular plant they form an intimate association with the finest division of the roots, wrapping tightly around them. This association works to the benefit of both parties. The fungus gets sugars produced by the plant through photosynthesis and the plant gets mineral nutrients that the fungus has absorbed from its environment. This combination of fungal mycelium and plant root is referred to as a mycorrhiza, which means, literally, fungus-root. Biologists are only recently beginning to appreciate how important the mycorrhizal association is. Almost 90% of vascular plants participate in these symbiotic associations and plants deprived of their mycorrhizal associates either die or fail to thrive. This is one reason why transplanting wild orchids almost never works. The orchid is completely dependent on its mycorrhizal associate for its mineral nutrition, especially nitrogen and phosphorus. When the orchid is removed from the wild a viable amount of the fungal associate fails to be carried along with the transplanted material. The orchid languishes in its new location and rarely survives more than a year without its fungal associate.

Bolete no. 1

Bolete no. 1, undersurface of cap showing pores

Two Lactarius sp., a gilled mushroom
note the "milk" on the gills

The first mushroom of the day was a large, brown bolete, followed by a large mushroom shaped like a smashed trumpet. The latter was a gilled mushroom in the genus Lactarius, so-named because if it is cut or broken the injured parts ooze a white fluid. The fluid can be clearly seen in the photo of a couple of small, white Lactarius. The Old Man of the Woods is another very distinctive bolete with its gray and black cap.

Old Man of the Woods (a bolete)

Dunson Native Flora Garden: One of the big surprises was the discovery of a Cauliflower mushroom right next to the path. While this is a basidiomycete it is neither a gilled mushroom nor a bolete. The spores are produced from tiny pores on the underside of each of the many lobes.

Cauliflower mushroom

We also found more Lactarius sp. as well as a red-capped Russula. Both these differ from other mushrooms in being brittle. The stems are not rubbery and easily snap when bent. All the members of both genera are mycorrhizal, especially favoring Oaks and Pine trees as their associated plants. Also seen were two Amanita mushrooms: White Amanita and the American Caesar Amanita with its bright red cap. Clearly visible on the White Amanita was the bulb at the base, from which the mushroom grows. Amanita mushrooms are notorious for their toxicity. Some are not so poisonous, but others are deadly, if consumed. Be safe. Don't eat any wild collected mushroom unless you are ABSOLUTELY confident of its harmless identity. Even experience mushroom hunters have made mistakes. One notable mushroom expert, the author of numerous field guides to mushrooms, and his wife were hospitalized overnight after consuming what they thought were edible mushrooms. If such people can make mistakes then amateurs should be very cautious.

White Amanita

American Caesar Amanita

Russula sp.

We also found out what the mystery fern from the last two weeks was: Marsh fern. It has been successful in spreading from its spot in the Dunson garden to cover quite a large area. We also found several individuals of Netted chain fern with fertile fronds. The Netted chain fertile pinnae stand away from the stalk but in the Sensitive fern the fertile pinnae remain closely applied to the stalk. The sterile fronds of this species are often difficult to tell from those of the Sensitive fern. The pinnae of the former are supposed to mostly alternate whereas the pinnae of the Sensitive fern are supposed to be mostly opposite. But the difference isn't clearcut and, without the fertile frond, it is hard to be confidant of your identification.

At the bottom of the Dunson garden the Great blue lobelia is no longer blooming, but the Cardinal flower still has a few blossoms. The Virginia saltmarsh mallow has lots of flowers, as does the Camphor weed and the spotted bee balm.

White trail (Power line right of way): I had hoped that the sun would be out by the time we reached the power line, but that didn't happen, so there was less insect activity than I had hoped for. But you make do with what you have and we had an opportunity to demonstrate one of the insects in the Order Orthoptera. The common orthopteran insect groups in this area are grasshoppers, katydids and crickets. There are other types of orthopterans, but these three are the most familiar. Almost everyone has seen a grasshopper and a cricket, but fewer have seen a katydid – even though most have heard them. We succeeded in finding one of the katydids so we could look at its distinguishing characters. 

The katydids (the official family name is Tettigoniidae) and crickets (Gryllidae)differ from grasshoppers (Acrididae) in having extremely long antennae – their antennae are longer than their total body. Cricket antennae generally are shorter than those of the katydids. Grasshoppers have very short antennae, much shorter than their body length.

Grasshoppers also differ from katydids and crickets in how they produce sound. Crickets and katydids make sounds by rubbing their wings together. One wing has a series of small ridges, called the file, while the other wing has a single ridge, called the scraper. To produce the sound the wings are held so that the scraper and file touch one another. The wings are then moved from side to side so that the scraper rubs against the file, producing a sound. If the wings are rubbed together very rapidly the sound produced is continuous. Each species of katydid has a specific pattern of sound that males produce to attract mates. 

Female katydids have a long, sword-shaped projection on the end of their abdomen. This is an ovipositor, an egg-layer. It is used to cut a slit in a plant stem and then insert an egg into the wound. Grasshoppers lack a conspicuous ovipositor and crickets have one that is shaped like a needle.

 

Grasshoppers can make sounds too, but they produce it by rubbing their legs against their wings. Some of the male grasshoppers do this when they are flying, which makes for a clumsy, bumbling performance, but the girl grasshoppers seem to like it.

But what good is producing sound if you can't hear? Katydids have ears, but not where you might think you would find them. Their ears are on the front legs (see photo). Grasshoppers also have ears, but they are located on the first abdominal segment.

Katydid; the ear openings are the dark ovals
near the "knees" on the front legs.
The wing pads begin just behind the light stripes on the thorax.

All three groups have what is called incomplete metamorphosis. This means that they have no caterpillar or pupal stage. When they hatch from the egg they look like miniature versions of the adult, except they don't have fully developed wings – they are just tiny little pads on the thorax. Each time the exoskeleton is shed the insect gets a little larger, but it still looks like a smaller version of the adult. The wings increase in size with each molt. Finally, at the last molt, the wings develop to the adult size.

With so many composites (family Asteraceae) in bloom right now this is an opportune moment to take a look at the structure of the composite flower. Flowers like sunflowers or daisies are called composites because what looks like a single flower is actually made up of many smaller flowers of different sizes and shapes. What look like the petals of a daisy are actually tiny flowers (florets) with one lobe of their corolla greatly developed. These are called ray florets. The center of the daisy flower, the disk, is made up of many tiny florets with radially symmetrical corollas. (Corolla refers to all the petals of a flower.) So daisy flower is really a mass of two different types of flowers: ray florets and disk florets.

When the ray florets are only found on the outer edge of the flower, as in sunflowers and daisies, they are usually sterile, incapable of producing seeds. Their function is to attract pollinators to the plant. The disk florets are fertile; each one of them is capable of producing a single seed. Consequently they typically have both male and female reproductive structures: stamens and pistils.

The stamens have a characteristic arrangement in the aster family – they circle the pistil and the adjacent anthers are fused to one another, making a hollow cylinder into which pollen is released. The pollen would remain inside this cylinder if it weren't for the pistil. After pollen release the style of the pistil begins to elongate. As it grows taller it pushes the pollen mass out of the floret, making it more accessible to pollinators. There is little risk of self-pollination, though, because the stigmas are not yet receptive. Another interesting feature: the style is split so when it emerges from the ring of anthers it appears to be forked or double. All these features can be seen in the close-up photo of a wingstem "flower." (I put the flower in quotes because it's really an inflorescence.) The anthers are visible as dark structures peeking out of the yellow disk florets. The split style with it's two stigmas can be seen emerging from the circle of anthers, the two stigmatic surfaces curled back. If you look carefully at the opened disk florets you can see the corolla lobes.

Wingstem flower showing ray florets, disk florets, anthers and styles with stigmatic surfaces exposed.

There are other composites in bloom today that do not have daisy-like inflorescences: Goldenrod, Late flowering thoroughwort, Ironweed, thistles. All these have florets that are like the disk flowers characteristic of the Asteraceae family.

Speaking of Ironweed, we found several with clumps of spittle. It's been a while since we talked about spittlebugs, so you may have forgotten. The spittle is produced by the nymph of spittlebugs, insects that are related to the cicadas. They nymph sucks fluid from the vascular system of its host plant and expels the excess from its anus. It creates the froth by adding mucous to this liquid and wiggling the end of its abdomen. The bubble of "spittle" protects the nymph from predators and parasites. They would have to penetrate the sticky mass to get at the insect inside. We wiped the spittle off and Don got a nice photograph of the nymph inside.

 

Ironweed with spittlebug foam

The spittlebug nymph exposed

We ultimately ran out of time so we returned back to the parking lot and some of us enjoyed converstation and beverages at Donderos'.

SUMMARY OF OBSERVED SPECIES:

Eastern gray squirrel	Sciurus carolinensis
Large, brown bolete	Order Boletales, Boletus sp.?
Large, cup-shaped Lactarius	Lactarius sp.
Small, white Lactarius	Lactarius sp.
Small red bolete	Order Boletales, Boletus sp.?
Old Man of the Woods mushroom	Strobilomyces sp.
Cauliflower mushroom	Sparassis sp.
Cricket	Orthoptera: Gryllidae
Netted chain fern	Woodwardia areolata
Marsh fern	Thelypteris palustris
Red Russula	Russula sp.
Triangulate orb weaver	Verrucosa arenata
Carrot-Footed Lepidella	Amanita daucipes
American Caesar mushroom	Amanita caesarea
Infected gray bolete	Order Boletales, Boletus sp.
Parasitizing fungus:	Hypomyces sp.
Green Russula	Russula sp.
White crownbeard	Verbesina virginica
Cardinal flower	Lobelia cardinalis
Rattlesnake master	Eryngium yuccifolium
Virginia salt marsh mallow	Kosteletzkya virginica
Giant ironweed	Vernonia gigantea
Camphor weed	Pluchea camphorata
Japanese Umbrella Inky	Coprinus plicatilis
Virgin’s bower	Clematis virginiana
Maryland senna	Senna marilandica
Wingstem	Verbesina alternfinolia
Large Cortisioid  fungi	Stereum sp.
Katydid  several stages	Family Tettigoniidae
Purple passion flower	Passiflora incarnata
Hairy sunflower	Helianthus hirsutus
Field thistle	Cirsium arvense
Virginia buttonweed	Diodia virginiana
Spittlebug	Order Hemiptera
False nettle	Boehmeria cylindrica
Leafy elephants foot	Elephantopus carolinianus
Small white morning glory	Ipomoea lacunosa
Red/Mexican morning glory	Ipomoea coccinea
Jewelweed	Impatiens capensis
Sensitive fern	Onoclea sensibilis