JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the woods a few miles east of
NATCHEZ, MISSISSIPPI, USA

June 10, 2012

MAPLEWORM
Deep in a heavily shaded, frequently flooded bottomland forest in nearby Homochitto National Forest, on the underside of a Red Maple's leaf a caterpillar an inch long (2.5cm) worked along the leaf's midrib. When he realized he was being watched he raised the front part of his body, causing the two slender, black "horns" sprouting from his shoulder area to look a bit threatening, and he froze, allowing the nice picture at http://www.backyardnature.net/n/12/120610cs.jpg.

Identifying such unusual caterpillars can be hard but volunteer identifier Bea in Ontario used a trick on this one. Instead of trying to figure it out on the basis of anatomy, she instead did an image search on the stab-in-the-dark word "mapleworm," and by golly she got some matching images.

One name for the caterpillar is the Greenstriped Mapleworm. It's DRYOCAMPA RUBICUNDA, and it'll metamorphose into a pretty, rosy-pink and creamy-yellow moth. As a member of the Saturniid Family, the Saturniidae, the moth this caterpillar will change into will possess only vestigial mouthparts and no digestive system. The moth's duty will be to have sex, the female to lay eggs, and then to die. The caterpillar's job is similarly simple: Just eat and survive.

Because of the caterpillar's small size I'd assumed that it was a young, early-instar one. However, I read that in this species larvae reach only about an inch long, like ours, so this must have been an adult. Fully-grown caterpillars pupate and overwinter in shallow underground chambers. Mostly they're found in eastern North America.

*****

FRESH-LOOKING BUCKEYE BUTTERFLY
Buckeye Butterflies are common here. This week one on a Brazilian Vervain was so brightly colored that I wasn't sure at first it was a Buckeye. Previously on our Natchez Butterfly page I had a faded Buckeye photographed at the end of the season in November, 2009, as seen at http://www.backyardnature.net/n/09/091101bk.jpg.

This week's can be compared at http://www.backyardnature.net/n/12/120610bu.jpg.

*****

BLACK LOCUST LEGUMES
This year I missed the pretty flowers of the Black Locust, ROBINIA PSEUDOACACIA, but I'm here as the trees' stiff, thin, legume-type fruits mature, as shown at http://www.backyardnature.net/n/12/120610bl.jpg.

Notice that the Black Locust's leaves are once-pinnately compound -- divided into 7 to 19 smooth-margined leaflets one to two inches long. A split-open legume with its hard, smallish beans nestled inside their chambers is shown at http://www.backyardnature.net/n/12/120610bm.jpg.

Black Locusts are common here in southwestern Mississippi so when I checked in my old Trees of North America field guide I was surprised to see that the species' distribution map showed us well beyond the Black Locust's two limited regions of natural occurrence -- the southern Appalachian region and just beyond, and the Ozarks. The USDA's "Plants Database" map more coincides with my experience. It shows Black Locusts present in all of the US 48 contiguous states and much of Canada. Also, on the Web I see that Black Locusts now grow wild in many countries throughout the world.

In my home area of Kentucky where heart-breakingly enormous acreages of countryside have been strip-mined for coal, much of that land has been "restored" by planting Black Locust on it. That's because Black Locust is a tough species able to live in very disturbed environments, plus, since it's a member o the Bean Family, its roots bear nitrogen-fixing mycorrhizal associations; the tree fertilizes the soil it grows in. Bees and other pollinators swarm to the flowers.

Still, apparently in most of the world Black Locusts are non-native species. In Massachusetts Black Locusts are prohibited as an invasive species. The "Global Invasive Species Database" complains that outside its native range Black Locusts compete with native plants for pollinating bees, and says that dense clones of the species create shaded islands with little ground vegetation.

So, technically, Black Locust is an "invasive" here. Nonetheless, in this fast-evolving world suffering so many attacks from so many directions, I'm glad to see the species enlisting with other plants and animals to vegetate and enrich ecosystems struggling just to exist -- just to hold the soil in place until the next clear-cutting, the next bush-hogging, and the next helicopter herbiciding.

*****

SILVERBELLS FRUITING
A small tree with slender branches overhanging a little stream in the bottoms bore broad leaves with low teeth along the margins, as shown at http://www.backyardnature.net/n/12/120610hb.jpg.

Nicely hidden in deep shadows below the leaves were some slightly immature fruits developed well enough to show what curious things they were. You can see them at http://www.backyardnature.net/n/12/120610ha.jpg.

This is the Two-wing Silverbell, HALESIA DIPTERA, a member of the little-known and smallish Snowbell Family, the Styracaceae. That family is home mostly to trees and shrubs that often bear showy flowers. Earlier in the spring our silverbell also bore inch-long (25mm), white flowers, but now they are long gone. The drooping flowers are pretty enough for the species to be planted widely as an ornamental.

Back in Kentucky and in other eastern states -- especially on moist, shaded slopes in the Appalachians -- I used to enjoy seeing the closely-related Four-wing Silverbell, Halesia carolina. That species occurs spottily in Mississippi, but here the main silverbell is the two-winged one, the two wings clearly visible on the fruits in the above picture. Our two-winged species is restricted mostly to the Deep South's Coastal Plain.

*****

BEAUTYBERRY FLOWERING
During earlier visits here we've looked at the Beautyberry's beautiful berries, as shown in a photo taken in October of 2009, still to be seen at http://www.backyardnature.net/n/09/091018bb.jpg.

Nowadays the Beautyberry bushes, CALLICARPA AMERICANA, are flowering, as shown at http://www.backyardnature.net/n/12/120610by.jpg.

A close-up of some flowers is at http://www.backyardnature.net/n/12/120610bz.jpg.

There you see that the corollas are parted into four lobes, not the more typical five, and that four stamens of equal lengths extend well beyond the corolla, and arise from the corolla tube's wall. These features, along with the stems' opposite leaves (two leaves arising at each node on the stem), all are characteristic of the Vervain Family, the Verbenaceae, to which Beautyberries are assigned.

*****

GIANT CANE
When I "go to the swamp" I bike past a bottomland woods at the edge of which rises a vigorous, beautiful stand of Giant Cane, ARUNDINARIA GIGANTEA, a native kind of bamboo. Bamboos are woody-stemmed grasses. You can see 20-ft-high (7m) plumes of Giant Cane gracefully swaying in wind blowing across a freshly planted soybean field at http://www.backyardnature.net/n/12/120610bd.jpg.

What a wonderful thing Giant Cane is, and what a shame we no longer remember how important it was to early people here, particularly indigenous people, who used it in their buildings, in making weapons, fishing equipment, jewelry, baskets, musical instruments, furniture, pipes, and medicines -- even its young shoots were boiled and eaten like asparagus.

Something interesting about Giant Cane is that it flowers only rarely -- by some accounts every 40 years or so. Mostly the species reproduces by sprouting. It's possible, maybe probable, that all the cane stems in the above picture are just shoots of one plant, the main "stem" being a much-branching, underground rhizome. Such genetically identical populations are called "genets." Each leafy bamboo stem lives for years until it flowers, and then it dies.

Therefore, it's unusual to find flowers. I've seen flowers a few times around here and my impression is that each population, or clone, flowers on different years than neighboring clones, so all of Mississippi's Giant Canes wouldn't flower at the same time.

In our area it's unusual to see such big cane displays as is shown in the picture, though before the Europeans arrived there were vast "canebreaks" covering hundreds of thousands of acres/hectares. More typically you see a few stems at a woods edge, or maybe some shade-stunted stems in a forest's understory, usually not over 10 feet tall (3m) and not growing very closely together. This week on a stem about head high I spotted some old, ready-to-fall flower spikelets atop a much-branching tuft of stems and leaves at the stem's top -- the tufts are called "top knots" -- shown at http://www.backyardnature.net/n/12/120610bb.jpg.

One of those spikelets, about 1½-inches long (4cm), apparently having weathered through an entire fall and winter, is at http://www.backyardnature.net/n/12/120610bc.jpg.

Giant Cane spikelets are typical of the grasses, basically like those of fescue or bluegrass, with a bottom pair of glumes subtending two overlapping ranks of six or more florets.

In the US we have three cane species, all in the Southeast, but only Giant Cane occurs in Mississippi. There's another species in the southern Appalachians, and a third along the eastern Coastal Plain.

*****

WILD SWEET POTATO FLOWERING
Along unmowed roadsides nowadays a pretty morning-glory is beginning to flower, the Wild Sweet Potato, also known as Man-of-the-Earth, Big-root Morning Glory and Man Root, IPOMOEA PANDURATA. You can see its distinctively white-with-purple-eye, three-inch-broad (8cm) flower, starting to wilt a little around the edges from intense mid-morning heat, and smallish, heart-shaped leaf at http://www.backyardnature.net/n/12/120610ip.jpg.

This is one of my favorite morning-glories, not only because it's so pretty, but because I can't see one without remembering my days hoeing tobacco back on the farm in Kentucky. Wild Sweet Potatoes were one of the most common weeds in our tobacco patches, and maybe the most aggravating. They'd twine around tobacco stems and have to be unwound individually, for if you just yanked on them their tough stems would shred the precious tobacco leaves.

You might guess that Wild Sweet Potato vines grow from edible tubers, especially since the "real" Sweet Potato, Ipomoea batatas is a member of the same genus. My experience is that tubers on such roadside vines as pictured above are too woody and scrawny to fool with, but I suspect that vines grown in rich, loose soil and frequently watered might produce something worth eating. I read that even such tubers are bitter and must be boiled, perhaps several times, to become palatable.

Indigenous Americans are known to have used the tubers medicinally. A "root tea" was used as a laxative, a diuretic, for lung ailments, and as a "blood purifier." The root mashed and made into a poultice was applied to aching joints.

*****

TIDAL WAVE SILVER PETUNIAS
Next to the parking lot where Karen works flowerbeds were carpeted with two-inch-high (5cm) herbs heavily laden with 1-1/5-inch-wide (3cm) flowers of many colors. Karen couldn't keep herself from plucking a few plants from the flowerbed edge and bringing them home. By the time they got to me the flowers were off and the leaves a bit crinkled but now, about a month later, I've coaxed the plants back to life. In fact, they're more robust now than earlier. You can see their first flowers at http://www.backyardnature.net/n/12/120610pe.jpg.

They're petunias! They hadn't been recognized from the beginning because so many petunia cultivars have been produced, mostly from hybridization, that nowadays it's hard to say what a "typical" petunia looks like. In general, petunias are much-branching, weak-stemmed and straggling herbs invested with long, sticky hairs ("viscid-pubescent"). A view of a blossom from behind shows certain other petunia field-marks at http://www.backyardnature.net/n/12/120610pb.jpg.

The corolla is funnel-shaped with five widely spreading lobes. The calyx is deeply five-cleft with narrowly oblong lobes, or sepals. Also, though petunias give the impression of exhibiting a rainbow of colors, the main ones are white and shades of pink to purple. Looking into the corolla's throat you see other distinguishing features, as seen at http://www.backyardnature.net/n/12/120610pc.jpg.

The green item with debris sticking to it is the pistil's sticky stigma, where pollen is supposed to land and germinate. Below the stigma are five pollen-producing anthers, all laden with purplish pollen. It is distinctive of the petunias that stamens are inserted on or below the middle of the corolla-tube, not below the ovary as so often is the case. Also, the five stamens are positioned with four of them paired, and the fifth much smaller or even rudimentary. The anther of this flower's smaller stamen is at the far left, clearly below the others.

The technical name for this particular cultivar -- learned by comparing a search engine's many thumbnail images -- appears to be PETUNIA X HYBRIDA 'Tidal Wave Silver.' The "x" in the binomial indicates that the taxon was produced by hybridizing two species, and "Tidal Wave Silver" is the cultivar name. I read that this cultivar is noted for its adaptability and weather tolerance, thriving even in the heat of the US Deep South.

Often the many petunia cultivars are grouped into four categories: Grandiflora; Hedgiflora (spreading); Multiflora, and; Milliflora. The cluster of "Tidal Wave" cultivars are regarded as Hedgifloras. They are used as groundcover, exactly as was the case next to the parking lot where Karen works.

*****

OLD MAN OF THE WOODS MUSHROOM
We've gone for a couple of weeks without rain, so mushrooms aren't as plentiful as they could be. However, next to my collards plot I erected a trellis for morning-glory vines and I've been watering the vines. This week that's where one of the most common and easy to identify of our mushrooms emerged, a dark, curious-looking one with a very shaggy cap about three inches across (8cm), shown at http://www.backyardnature.net/n/12/120610om.jpg.

It's the Old Man of the Woods, STROBILOMYCES FLOCCOPUS, whose main field mark is those large, blackish scales on the cap separated by narrow white areas. Also, you can see that on the cap's underside there are pores, not gills. A better view of that is at http://www.backyardnature.net/n/12/120610on.jpg.

This being a pored mushroom, thus part of the group generally known as "boletes," and knowing that boletes typically are good eating, it's not surprising that the Old Man is edible. However, its flavor isn't anything special.

Ecologically, Old Man of the Woods forms mycorrhizal associations with the roots of hardwood trees. That means that its subterranean hyphae form sheaths around the roots, penetrating the roots somewhat, effectively increasing their surface area, thus enhancing their ability to absorb water and nutrients. The fungus benefits by having access to sugars and amino acids in the roots.

Old Man of the Woods occurs from Nova Scotia to Florida, west to Michigan and Texas.

*****

FEATURED ESSAYS FROM THE PAST:

"Snake Brain, Spinoza & Scientific Pantheism" from the September 7, 2006 Newsletter, at http://www.backyardnature.net/n/p/060907.htm.

"Digging Potatoes" from the September 20, 2009 Newsletter, at http://www.backyardnature.net/n/p/090920.htm.

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at www.backyardnature.net/n/.

Visit Jim's backyard nature site at www.backyardnature.net