July 29, 2012
BUMBLE BEES ON PEARS
Though nowadays I eat between six and ten pears daily -- mostly sliced into cornbread batter and baked over a campfire to produce something like a sweet, juicy pear cobbler -- several pears do escape me and end up rotting in grass below the trees. During the night deer and other critters come and chomp on them, and all day long bumble bees cluster on the pears' exposed interiors, apparently drinking sweet pear juice as shown at http://www.backyardnature.net/n/12/120729c_.jpg.
Another view of the bee is shown at http://www.backyardnature.net/n/12/120729cb.jpg.
Wing venation is shown at http://www.backyardnature.net/n/12/120729ca.jpg.
This bumble bee doesn't look like the ones usually illustrated for eastern North America. There are different species of them and what we have here in southern Mississippi isn't the one I grew up in Kentucky calling a bumble bee
YELLOWJACKETS ON PEARS
Those overripe, deer-chomped pears beneath the orchard trees also attract juice-craving yellowjackets such as the one shown at work at http://www.backyardnature.net/n/12/120729yj.jpg.
Calling this a yellowjacket isn't being very precise because in North America the name yellowjacket is applied to several species in two distinct genera. Just in Florida, for instance, 18 species of the genus Vespula and one of Dolichovespula are regarded as yellowjackets. However, they're all members of the subfamily Vespinae. The good news for us yellowjacket identifiers is that at the DiscoverLife.Org website there's a wonderful, interactive, well illustrated identification guide to the Vespinae of North America, at http://www.discoverlife.org/mp/20q?guide=Vespinae.
Thanks to that exceptionally useful key I know that what's enjoying our fallen pears is the Eastern Yellowjacket, VESPULA MACULIFRONS. At first I was unsure of the ID because the yellow patterns on my wasp's thorax and abdomen are slightly different from most of those illustrated on the Internet. However, there's great variation in these patterns. Often it's the case that northern variations are much better documented than those from this area.
Yellowjackets and hornets are different species, though both are members of the subfamily Vespinae. In general, hornets are much larger and show fewer yellow markings. Hornets prey on live insects but yellowjackets feed not only on small arthropods but also carrion and fruit juices. Both yellowjackets and hornets enclose their papery nests in a surrounding comb. In nature, yellowjacket nests normally are subterranean (sometimes in decaying stumps), though in urban areas often they're built in hollow walls, attics and the like. Hornets place their combs in trees and bushes, and sometimes below house eaves.
Both impart painful stings, some of which I've written about in Newsletters.
Biking across an old-time, one-lane wooden bridge over a nearby creek I was tickled to see across the railings the top of a Boxelder tree, ACER NEGUNDO, heavy with paired, samara-type fruits. You can see a typical branch at http://www.backyardnature.net/n/12/120729bx.jpg.
Being on the bridge was important for that picture, for the tree's lower branches were fruitless.
People familiar with maple species such as Sugar, Red and Silver Maples often are surprised to learn that Boxelders are real maples, too -- members of the genus Acer. The paired, winged fruits are typical maple, but what's not like those other species are the leaves. The vast majority of the more than 100 maple species bear simple leaves -- leaves composed of a single, flat blade. Boxelder leaves are compound, as shown at http://www.backyardnature.net/n/12/120729by.jpg.
That picture is mostly filled with two leaves, each comprising five leaflets. Their slender petioles attach opposite one another on the green stem at the picture's top, center. The greenness of the main stem passing vertically through the picture's center is another peculiarity, for not many trees bear year-old, green twigs.
Also among the maples Boxelders are a little unusual in being completely "dioecious" -- trees bear either male or female flowers, but not both.
As a kid on the Kentucky farm the Boxelder was one of the first trees I learned to identify because most of the shade trees around our house were Boxelders. My father chose to plant them because they were so fast growing, grew into pretty shapes and produced good shade. In late summer their leaves did tend to wilt, curl up, turn brown, and drop off early from diseases, but that didn't seem to affect the tree's general growth throughout my entire childhood. Boxelders are known for being plagued by a variety of diseases. The ones in our picture look pretty droopy and show signs of fungal infections themselves. Also, Boxelders' fast-grown branches tend to be weak and brittle. I remember picking up many big limbs broken from them by storm winds and freezing rain.
Boxelders display an interesting area of distribution. They're native from well into south-central Canada to the Texas Gulf Coast and throughout most of the eastern US, but not on much of the eastern Coastal Plain, and not in New England. Island populations are scattered here and there in the western US and at higher elevations in southern Mexico and Guatemala. The Mexican and Guatemalan communities were left there as the last ice-age glacier retreated in the north, with many northern-forest species, instead of following the cool weather back north, sought cooler climes at higher elevations.
Boxelders are vigorous, adaptable trees. In much of Europe as well as Asia, South America and Australia invasive communities of Boxelders have become established. Also, in the wild, normally Boxelders grow along streams, in swamps and such, but if you transplant them into a dry, suburban lawn normally they do pretty well. In fact, a number of cultivars have been developed, including 'Auratum' with intensely yellow autumn leaves, 'Flamingo' on which young leaves emerge bright pink, and 'Variegatum,' with variegated leaves.
COCKSPUR HAWTHORN'S JULY FRUITS
In the world of tree taxonomy, the hawthorns -- genus Crataegus -- are an especially hard group to figure out. Being members of the Rose Family producing flowers similar to plum blossoms, and fruits like crabapples, with stems often armored with substantial spines, normally it's easy to see that a hawthorn is a hawthorn, but figuring out the species can be difficult to impossible. Impossible because even the experts aren't in agreement. In the past a thousand or more species were recognized, most of which now are regarded as simple variations of other species. A good guess is that there's around 200 hawthorn species, but especially in North America it's just not clear what's what.
However, at a woods edge along a loess ridge near here an obvious hawthorn turned up that I was pretty sure I recognized as a common species from my Kentucky days. You can see its leathery, lustrous-topped leaves, green fruits (the haw, which later in the season will turn bright red) and slender, three-inch-long spine (7cm) at http://www.backyardnature.net/n/12/120729cr.jpg.
You can see an immature haw, which later in the season will turn red, topped by its characteristic, long-enduring sepals, with a few of spring's blackened, dried-up stamens lying among them, at http://www.backyardnature.net/n/12/120729cs.jpg.
This is the Cockspur Hawthorn, CRATAEGUS CRUS-GALLI, distinguished among the many hawthorn species for its unlobed leaves that are widest above their middles and with their lower blade margins gradually diminishing toward the petiole's point of attachment, providing the petiole with "wings." Most Cockspur Hawthorn leaves found on the Internet are not as broadly rounded as ours, except from trees from Alabama and eastern Texas. Apparently trees in our general area have blunter tips than more northern ones. Cockspur Hawthorn is famous for being very variable, and for having been given a particularly large number of names by botanists who were sure they'd discovered a new species.
Cockspur Hawthorn is an especially handsome and adaptable species, which accounts for horticulturalists having developed several cultivars from wild trees, including a thornless form.
Theoretically the cherry-sized fruits are edible, but there's much more bony seed than flesh and the flesh is dry and not very tasty, so unless you're starving or just want to nibble on something, these are best left to wildlife, which of course relish them, especially the birds. Certain birds build nests inside the tree, whose denseness helps hide the nests, and whose spines protect them.
BUTTONWEED'S LITTLE WHITE X-FLOWERS
Along a hot, sun-beaten gravel road through a bottomland woods a much branched, ground-hugging wildflower formed a mat of dark greenery about the size of a car tire. Sprinkled all through its herbage were little white flowers with four-lobed corollas, looking like flattened exes, as shown at http://www.backyardnature.net/n/12/120729di.jpg.
A close-up side view of a blossom showing its ¼-inch long (6mm) tube topped with hairy-topped lobes, and four stamens and two slender stigmas emerging from the tube, is at http://www.backyardnature.net/n/12/120729dj.jpg.
That picture also shows features letting us know what family the little plant belongs to. Notice that two leaves arise opposite one another on the stem, instead of the somewhat more frequent single leaf, plus between the leaf bases there's a line of deeply divided leafy tissue, the stipule. When you have opposite leaves and a conspicuous, permanent stipule like this, you should think of the mostly tropical Coffee or Madder Family, the Rubiaceae, in which we also find not only coffee bushes but also gardenias and Partridge-Berries, all with opposite leaves and conspicuous stipules.
This common, tough little roadside weed is the Virginia Buttonweed, DIODIA VIRGINIANA, a native of the US Southeast and bordering states, found along the coast as far north as Connecticut, plus it's becoming an invasive in numerous other tropical and subtropical countries. There's another common, closely related and similar buttonweed, Diodia teres, but that species is more erect -- doesn't creep across the ground like this one -- plus its leaves are narrower and its stipule lobes more slender and numerous.
Virginia Buttonweed is most commonly found in wet areas such as ditch bottoms and pond edges, much in contrast to the sun-pounded gravel at the edge of this road. However, just a yard (meter) away the road edge dipped just enough for the road to drain into and we've had a rainier than normal season so far, so this must account for our plant being able to sprawl onto the gravel road. As such, it was performing important ecological duty merely by converting a glaring, extremely hot, desert-like patch of lifeless sand and gravel into a dark green community of life that bugs could munch on even as the plant itself protected the sand and gravel from erosion, and photosynthesized oxygen for us all.
When I arrived here in early April I found several packages of garden flower seeds, all three or four years old. Despite wondering whether the seeds would still be viable I sowed them in a garden spot. Only the four-o'clocks came up in profusion, plus a couple of knee-high plants of what's shown at http://www.backyardnature.net/n/12/120729cd.jpg.
One unusual feature of this plant is its "digitately compound" leaves -- leaves with their leaflet bases all united at one spot atop the leaf stem, or petiole. The compound leaves of most plants have their leaflets arising from a continuation of the petiole, the rachis. The flowers also are unusual, as shown at http://www.backyardnature.net/n/12/120729ce.jpg.
On this bilaterally symmetrical, or "zygomorphic," blossom you see only four petals held above six broadly spreading, pollen-producing stamens. Also, each blossom does something curious as it unfurls, as shown at http://www.backyardnature.net/n/12/120729cc.jpg.
As stamens emerge from the opening flower their anthers are protected as long as possible by wrapping them in the petals, which still are united into a cylinder. It's important to protect anthers because they produce pollen, the grains of which bear male sex germs. The female sex germs are even better protected in ovules inside the fleshy ovary nestled down inside the filaments' bases at the flower's bottom.
The most commonly used English name for this plant appears to be Spider Flower or Spider Plant, which are names used for many unrelated species. It' also called Spider Legs, Grandfather's Whiskers, Crown Flower, etc. Nowadays it's technically known as CLEOME HASSLERIANA, though in older publications it's listed as Cleome spinosa.
The plant family you think of normally producing flowers with four petals and six stamens in the Mustard Family. However, this garden plant is not a Mustard Family member. It's in the much smaller, mostly tropical and subtropical Caper Family, the Capparidaceae. In a close-up of our plant's flower interior you can see what separates our Spider Flower from all members of the Mustard Family at http://www.backyardnature.net/n/12/120729cf.jpg.
At the picture's top, right corner you see the dark purplish ovary -- the future fruit -- held far above the point where the flower's filaments and petals unite. The ovary stem, or "gynophore," is what distinguishes the Caper Family from the Mustard Family. Mustard-flower ovaries don't grow atop gynophores. Otherwise, the long, slender, many-seeded, capsular fruit looks just like a mustard-family fruit.
Spider flowers are tropical American plants that can be grown in summer gardens in many temperate countries. Several cultivars have been created. If you enjoy comparing technical features of flowers, you might like to compare the blossom of our present Cleome with one we found in a garden in southern Mexico of Gynandropsis speciosa -- a completely different genus -- at http://www.backyardnature.net/chiapas/cleome-7.jpg.
At first glance this Gynandropsis's flower structure looks identical to our Cleome's, but notice that the stamens' filaments unite on the gynophore well above the gynophore's base -- not at the base as in Cleome. That's enough to cast this group of flowers into an entirely different genus!
TINY MARASMIUS MUSHROOMS
Much in contrast to most of the US, here in southwestern Mississippi our July has been fairly rainy with many afternoon storms. In the grassy orchard huge numbers of a thumbnail-sized-and-smaller, pale tan mushroom become very conspicuous soon after any good rain, as shown at http://www.backyardnature.net/n/12/120729m1.jpg.
If rains fail for a couple of days the mushrooms shrivel up, contort into very unmushroom-like shapes, and look completely dead, but as soon as the next rain comes they resume their former shapes, maybe only with their cap rims looking a bit more ragged. In the science dealing with fungi, mycology, this ability for a dried-out mushroom to assume its previous proportions is known as "marcescence."
These orchard mushrooms are not rooted in soil but rather on individual or stuck-together leaf blades or single grass stems. You can see two arising from a moldy Cherrybark Oak leaf, with the tip of my index finger nudging in from the side for scale, at http://www.backyardnature.net/n/12/120729m3.jpg.
In that picture notice the white, powdery stuff on the leaf's undersurface. That's the actual "main body" of the fungus, the mycelium. Mushrooms are mere reproductive structures of the white stuff, which is actually a complex, intricately branching network of threadlike fungal hyphae. The individual thread is a hypha, the clumped-together hyphae form mycelium. The hypha strand grows through the leaf's dead tissue breaking it down into chemical components the fungus uses as food. Doing this, the fungus performs a profoundly important ecological function by contributing to the leaf's decomposition, and helping make nutrients locked in the leaf available to other living organisms.
You can see the underside of this mushroom's cap, showing the gills from which spores fall, at http://www.backyardnature.net/n/12/120729m2.jpg.
Without being able to examine our tiny, marcescent orchard mushroom's white spores with a microscope I can't be sure which species it is, but my best guess is that it's MARASMIUS DELECTANS, a common species in decaying leaf litter, especially oak leaves, widely distributed in North America east of the Rockies. Besides its ecology (on a decaying oak leaf), size, and cap and spore color, an important field mark for this species is its slender, tough stem that is dark below but very pale near the cap.
Marasmius species are numerous and often abundant. If you have similar ones around your house and want to figure out which species you have, Michael Kuo at MushroomExpert.Com provides a fine introduction to the genus and a good key to species at http://www.mushroomexpert.com/marasmius.html.
BEAUTIFUL AMANITA MUSHROOMS
About three days after a particularly heavy rain, in a grassy, shaded spot beside my trailer, six uncommonly large and pretty mushrooms emerged from the ground. You can see one soon after its emergence, still not with its "mushroom shape," about 2-½ inches high (6cm) at http://www.backyardnature.net/n/12/120729m4.jpg.
Two days later that same mushroom was about five inches tall (13cm) with a fully deployed cap, as shown at http://www.backyardnature.net/n/12/120729m5.jpg.
One spectacular feature of this species is its very well developed, skirt-like "ring," or "annulus," encircling the top of its stem just below the cap. Note the dark "warts" atop the pure white cap. A blade of grass touching the gills from below was coated masses of spores fallen from the gills and their color was white. A closer look at the cap's warts is at http://www.backyardnature.net/n/12/120729m6.jpg.
When you have a large, white-spored mushroom with a ring and a warty cap the best bet is that you have an Amanita mushroom -- one of the most famous of mushroom groups because not only are they a delight to see but also because some of the Earth's most deadly species belong to this genus. The killer Destroying Angel, Death Cap and Fly Agaric are Amanitas. However, this was none of those. About 600 Amanita species are recognized worldwide, so I wondered whether I'd ever be able to identify this one.
As it turns out, though I can never be sure without microscopically examining the spores, my trailer-side visitors are graced with such unusual features that with this species I'm fairly confident of the ID. Besides its white spores, the skirt-like ring and the white cap with dark warts, another very distinctive feature is the much-thickened, or "bulbous," base bearing conspicuous circles of scales, as shown on a young individual at http://www.backyardnature.net/n/12/120729m7.jpg.
This is AMANITA COKERI, without any good English name unless we bestow the obvious name of Coker's Amanita. It's mostly a southeastern US species, where it's regarded as common, though it's also known from Idaho and Illinois. Its hyphae form mycorrhizal associations with roots of both hardwoods and conifers. Our Mycorrhiza webpage is at http://www.backyardnature.net/f/mycorhza.htm.
Amanita cokeri is listed as "not edible," which isn't nearly as bad as "deadly poisonous." Some of the most dangerous Amanita species smell bad, but these just have a mild, fungusy odor.
About 35 feet (10m) from the population of Amanita cokeri, in a spot receiving more foot traffic but still mostly grassy, yet another small group of large, white mushrooms producing white spores arose. You can see a four-inch tall one (10cm) at http://www.backyardnature.net/n/12/120729m9.jpg.
The cap is strewn with debris gathered while emerging from the ground; it bears no scales or "warts" like Amanita cokeri. A striking feature of the cap is its distinct, slender lines radiating from the center. Also notice that in this species no ring encircle the stem just below the cap, but the stem does arise from a cuplike structure, the "cup," or "volva," a close-up of which is shown at http://www.backyardnature.net/n/12/120729m~.jpg.
So, is this yet another Amanita? It turns out that it is, one common enough to bear a common name. It's the Grisette, AMANITA VAGINATA, an ID arrived at with the help of Michael Kuo's "Key to a Few Common and Distinctive Amanitas" at http://www.mushroomexpert.com/amanita_commondistinctive.html.
But, Michael Kuo also says that "... likely, there are many species going under the name 'Amanita vaginata.' Amanita expert Rod Tulloss treats literally dozens of unnamed, vaginata-like, numbered taxa ("species 46," and so on) in his keys to North American amanitas."
Another field mark apparent on older mushrooms with caps darkened with age is a curious little hill, or "umbo," in the cap's center, as shown on the same mushroom shown above a few days later after who-knows-what misfortunes removed hunks of its cap, at http://www.backyardnature.net/n/12/120729m8.jpg.
As demonstrated by our mushrooms, ecologically Grisettes specialize in, as Kuo writes, "... grassy areas at the edges of woods -- or in lawns that are not meticulously manicured." Grisettes are widely distributed throughout North America.
They are listed as edible but casual collectors are warned to avoid them because they can so easily be confused with poisonous look-alikes.
FEATURED ESSAYS FROM THE PAST:
"Fine-Tuning Buddha" from the January 2, 2011 Newsletter, at http://www.backyardnature.net/n/p/110102.htm.
"The Middle Path" from the May 2, 2004 Newsletter, at http://www.backyardnature.net/n/p/040502.htm.
Best wishes to all Newsletter readers,
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