A Neighbor With a Lot of Gall

Growing next to the sidewalk just around the corner is an eyecatching oddity. These should be leaflets of an ash tree's leaf, but instead they bear an uncanny resemblance to a butterfly's chrysalis.

This is a normal ash leaf, with a bunch of leaflets.

Here, the development of each leaflet has been altered to make the chrysalis-like structure. Sure looks like something should be living inside.

Open it up to find the midges living the good life, well protected by the distorted growth of the leaf, and with ample food to reach maturity in a month or so. The larvae drop to the ground, overwinter in the soil, then emerge in the spring as adults to climb up the ash tree in time to lay eggs in the emerging leaves. The midge injects the rapidly growing leaf with a hormone-like chemical that causes the leaf to grow in a conveniently distorted manner. (Nice description found here.)

The latin name for the midge, a kind of fly, is Dasineura tumidosae. Considerable internet searching yielded no common name other than "ash gall". Here's some more info.

One of the more common galls on ash is the ash flower gall, which can be seen in the canopy in the spring, before leaves emerge. Thinking back to our hike up Baldpate Mountain a month ago, I realized we had been looking up at an ash that looked like it had growths on the twigs high up, wondering what it was. Probably ash flower gall.

A question to be asked is how closely tied is the fate of all of these organisms to their host plant. If our ash species succumb over the next ten or so years to emerald ash borer, whose presence in New Jersey was documented for the first time this past week (more on this later), will all of these insect species find other hosts, or disappear along with the ash? A tree like the ash, which can develop considerable stature and grandeur, feeds an entourage of less charismatic creatures. At least one of them I can now count as a neighbor. 

The Richness of Richweed

When it comes to flower biology, the more you look, the more you see. Sometimes a single observation can open up a whole new world. What, for instance, is going on here? Some sort of tiny bee is ignoring the main flower and instead doing a high wire act to nibble on the tip of a stamen jutting out from the petals.

I had been content to largely ignore this fairly rare native plant growing in my backyard. It's sometimes called horsebalm (for no clear reason), or stoneroot (for its hard, medicinal root), but I prefer to call it richweed, because it has a preference for rich woodland soil, and the idea that something called a "weed" is also rich is appealing. I had rescued a couple from the path of a stream restoration, had read that it rates 9 on a scale of 10 on the plant stewardship index, and was content just to know it had escaped the bucket of a backhoe. In a mixture of sun and shade, it's fairly attractive when massed, with leaves reminiscent of hydrangea, but the flower doesn't grab one's attention.

This summer, though, with cool weather bringing outdoor comfort and extended flowering lengths, I finally paused long enough to check out what sorts of pollinators the richweed was attracting. Mainly bumblebees, which look perfectly matched for this flower, bobbing from one to another, giving each one a bear hug as they sip the nectar. The flower is so shaped, with the stamens jutting out on either side of the flower, to appear as if the embrace is mutual.

But then there was another kind of bee, smaller, that was, as mentioned, feeding not on the nectar but solely on the pollen at the end of each long stamen.

Stepping inside to browse the internet, word comes that richweed's flowers are lemon scented--fitting for a plant in the mint family. The root has medicinal qualities, and the stamens are described as "exserted", meaning protruding. (Those are the two finger-like protrusions that frame the flower.) One of the perks of learning some botany is that you're likely to encounter words otherwise lost from the english language. The companion for "insert" lives on in descriptions of flowers in dusty botany manuals.

While digging up lost words, why not give the internet a companion as well, i.e. the externet, or outernet--that being the web of life in the real world, the great outdoors, nature. One prompts exploration of the other.

A deeper look at the externet, in the form of a long ignored flower, prompted a deeper look at the internet and what it has to say about richweed. One link led to a discussion of autogamy in The Natural History of Plants. Richweed (Collinsonia canadensis) fertilizes itself when the stigma at the end of the long style (purple with a tiny fork at the end, in the photo) bends over and touches the anther at the end of one of the stamens. Here's how it reads in the book:

"The accomplishment of autogamy through the inclination of a style otherwise straight is of even less usual occurrence. The most striking example of this process is afforded by the bilabiate flowers of the North American Collinsonia canadensis. In the newly-opened blossom the long style stands midway between two exserted stamens which are almost as long as the style. Towards the end of the flower's period of blossom, the style begins to slope towards one of the stamens, moving like the hand of a clock through an angle of from. 20" to 40" until its stigma comes against the pollen-covered anther borne by the stamen in question."

In this photo, you can see the (female) style of the flower on the left reaching over towards the (male) anther of the other, which in "The Botanic Garden, A Poem in Two Parts" becomes invested with great meaning:

"But I was this morning surprised to observe ... the manifest adultery of several females of the plant Collinsonia, who had bent themselves into contact with the males of other flowers of the same plant in their vicinity, neglectful of their own."

It's good to know that, if we ever run out of human indiscretions to feed the rumor mill, plants stand ready to fill the void.

The journey into the internet also brought up a marvelous text by William Bartram, early botanical explorer who made a late 18th century trip through Cherokee country.

"AFTER leaving the low grounds and ascending the hills, discovered the plant I went in search of, which I had before frequently observed in my descent from the Creek nation down towards Taensa. This plant appears to be a species of Collinsonia; it is diuretic and carminative, and esteemed a powerful febrifuge, an infusion of its tops is ordinarily drank at breakfast, and is of an exceeding pleasant taste and flavor; when in flower; which is the time the inhabitants gather it for preservation and use; it possesses a lively aromatic scent, partaking of lemon and aniseed."

Rich it was and rich it remains, this richweed, a valued remnant of the abundant wealth in that wild garden known as America.

Bamboo--Edibility, Priability, Liability

A few weeks ago, as the local patches of bamboo were launching their spring offensive, consolidating their holdings of pricey Princeton real estate while expanding across fencelines into new territory, I encountered a Chinese man on the sidewalk, carrying a plastic bag of bamboo shoots. He looked like the real deal, as if he'd just stepped out of the labyrinth of a traditional Hutong neighborhood in China. Resident tourist that I am, I asked if I could take a photo, but he didn't speak English, and headed off towards the senior housing down the street.

His harvest had probably come not from McCaffery's but from a patch of rogue bamboo across the street,

whose adventurous sprouts periodically block drivers' views, get trimmed, and end up in a heap in the street.

With another neighbor's bamboo continuing to invade our yard, the edibility angle sounded worth pursuing.

As an experiment, I collected some and undertook a dissection of one on the back patio. Despite bamboo's reputation as a very tough customer (their toughness comes from a combination of silica and lignin), only a few outer leaves needed to be stripped off of the terminal shoot to reach the soft underbelly of this most imperialistic of backyard plants.

The next step would be to start eating, but there were questions. Are all species of bamboo edible? If only some, then is the local species one of them? Does it need to be cooked first? I was not looking forward to cracking a thick tome on grasses and analyzing microscopic features to figure out which of the 1450 species of bamboo I had just harvested. The botanist might become comatose before figuring out if the lemma is comose.

LIABILITY: Fortunately, an article in Mark Twain's old newspaper, the Hartford Courant, popped up in an internet search, telling of a law that passed the Connecticut House of Representatives last month by a vote of 130-3, requiring that "running bamboo" be

"set back at least 100 feet from abutting property. It also requires people who sell or install running bamboo to educate customers on the plant’s growing habits and recommended containment methods. A fee of $100 is prescribed for violators of either requirement.

The bill makes people who plant running bamboo liable for any damage the bamboo causes to neighboring properties, including the cost of removing any bamboo that spreads to neighboring properties. 

The measure passed the state Senate unanimously last week."

What is running bamboo, one might ask. Turns out there are two main growth forms of bamboo, running and clumping. Clumping forms are better behaved. I found conflicting information about whether there are clumping species that grow well enough and high enough to provide the sort of screening people look for from bamboo. Here's one of many links.

PRIABILITY: The Courant article mentioned Phyllostachys aureosulcata — yellow groove bamboo--which it called "the poster child for aggressive bamboo in Connecticut". Established stands of the species can travel 15 feet underground in a single year. When it reaches a house foundation, it can send shoots up underneath the siding, prying the siding off the house as it pushes upward.

It wasn't hard to find a local example of this. Fortunately, these are slender shoots, but could still do some damage.

Yellow groove bamboo, fortunately, is easy to identify. Nicknamed "crookstem bamboo", it often has crooks in the stem. The bamboo growing in my neighborhood has crooks in the stem,

as well as the characteristic yellow groove above the branches.

EDIBILITY: The silver lining in this yellow grooved poster boy for aggressiveness was found in this description of the species: "Cultivated mainly as an ornamental, this species is also among the best for edible shoot production, being free of acrid flavor even when raw."

So, thanks to a chance encounter with a Chinese neighbor, the world has become a more interesting, more edible place. There's still a question as to whether the tips of stems that have already grown several feet high can still be eaten. Though the Chinese man's harvest looked to be from stems already well above ground, this video suggests they have to be harvested just as they are emerging. The color of the flesh should be brown rather than the green said to make older shoots bitter.

Given human nature and the ease of buying bamboo shoots at the store, there's no way that harvesting will solve the problem of bamboo aggression in suburbia. There are other, less edible invasives pouring across fencelines--Japanese honeysuckle, English ivy, ground ivy. Fortunately, none of these threaten to pry siding off of houses or push up through asphalt driveways. Bamboo's destructive capacities make it a pioneer in exploring the liability gardeners may bear for plants that escape from their yards. Regulation is often characterized as an intrusion by government into people's lives, but more often it offers a means of protecting us from intrusion. With all sorts of pollution--biological, chemical, sonic--"freedom to" impinges on a "freedom from". That's something to meditate on while nibbling on some tasty bamboo shoots.

Info about harvesting and preparing: http://agsyst.wsu.edu/bambroc.pdf

Informative post with frequent mention of yellow grooved bamboo: http://waynesword.palomar.edu/ecoph39.htm

Info about nutritional content:

http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2011.00147.x/full

Sailing and Seaside Solidago

Sailing is a lot like gardening in that it teaches one to work with nature rather than against it. Yesterday, I helped a friend get his most-amazing sailboat ready for the winter. I say most-amazing because I had not before been on a sailboat that's been around the world three times. My previous notion of a great sailing adventure came from camp counseling days when I took some high school kids from Camp Innisfree, near Sleeping Bear Sand Dunes, out to Lake Michigan's South Manitou Island in a daysailer. 

This boat, called Makulu, which in an African language means "big happy Momma", is equipped to nurture far greater ambitions.

For the time being, though, it will spend the winter with all the others, parked on stilts.

Among the emotional struts keeping my love of sailing well supported and ready to launch at any moment through all these non-sailing years is surely that feeling of acceleration experienced many decades ago when a strong breeze hits the sails. There's the sheer elegance and gracefulness of sailing, the economy of well-trimmed sails, the great good luck--a sort of alchemy--of being propelled forward with no effort beyond keeping a good grip on the rope and tweaking the rudder. Sailing permanently associates the elements of sustainability--renewable energy, efficiency, reuse--with pleasure. Experiencing how something invisible can power travel is also good training for understanding how carbon dioxide could be so transformative.

While big happy Momma was getting a good powerwashing to knock off the accumulated barnacles and algae, I decided to do some seaside botanizing. A jumble of concrete may not look like the most promising spot to explore, but it yielded some beauty and meaning.

First seen was an encounter between two grasses. The smaller one I'll say is smooth cordgrass (Spartina alterniflora), with the proviso that my coastal botany chops haven't been refreshed since the days of reading Rachel Carson's descriptions of two species of Spartina in the salt marshes decades back. In the background, taller and with pompoms for seedheads, is Phragmitis. It's a pretty picture, but there's drama beneath the tranquility.

Phragmitis is both beautiful and a botanical bully. In a freshwater wetland, it is the uber-invasive exotic, able to overwhelm even the aggressive native cattail. Here, the peaceful scene shows nothing of the underground battle being waged, as the Phragmitis' rhizomes invade the cordgrass' territory, ready to outcompete, overshadow, and ultimately displace. Meanwhile, the smooth cordgrass, loved as an integral part of the coastal ecosystems of the eastern seaboard, is proving detrimental and bully-like where it has been introduced into the differently evolved marshes of the west coast. As they say in real estate: location, location.

Here, the cordgrass plays off the sailboat masts in the distance.

One tough beauty blooming in the rubble is Seaside Goldenrod, Solidago sempervirens.

Bees were showing appreciation.

(Time out here to take a swipe at that most durable of botanical falsehoods, which thrives even in the minds of many nature lovers--that being the stubborn belief that goldenrod is allergenic. No. Ragweed, an unassuming wind-pollinated plant that blooms at the same time, is the one that produces the symptoms people falsely associate with goldenrod. How that falsehood has been able to thrive without periodic smear campaigns should be a topic of political science research.)

Here's an evening primrose growing up through Japanese knotweed.

The knotweed, whose invasive tendencies seem muted by the salty environment, grows next to a big clump of native indigo bush (Amorpha fruticosa), a legume whose acacia-like, bluegreen foliage can provide an appealing contrast in a backyard garden.

All this mixed talk of beauty and invasiveness is really about balance, which sailing teaches as well. Give us wind, but not too much or too little. Nearly two years ago, this sailboat and all the others at this marina got a big gulp of too much wind, when Hurricane Sandy rolled in, piled boats as if they were toys, and sank this sailboat in the harbor. To salvage the mast if nothing else, it was deemed worth pulling up out of the muck.

The plants, I'm sure, dusted themselves off and went back about their business of growing.

Vines in Winter

Fortunately, Mountain Lakes Preserve has not been invaded by Bermese pythons (check out NOVA this coming Tuesday on PBS), despite the appearance of this poison ivy vine. It looks like it grew a winter coat, but poison ivy vines are always hairy, which rhymes with scary.

In this photo, the poison ivy is almost as big as the tree its climbing on. Looks like an angler stashed some fishing line inbetween the two.

Further up, it looks like the tree has lots of branches, but these are actually the vine's lateral shoots, which will bear flowers and berries later on. What we have here is essentially a poison ivy tree held upright with the help of a "donated" trunk.

The vine with the shaggy Irish setter-like bark is wild grape.

Native vines like poison ivy and wild grape tend not to grow in a way that would strangle the trees that support them.

Japanese honeysuckle, on the other hand, was spiraling up this shrub in a way that would eventually choke it. The trunk of the shrub was already getting distorted by the vine's tight grip. Note exotic honeysuckle vine's stringy bark, lighter in color than wild grape.

Turned out that the shrub was an exotic Asian photinia, so we cut both the shrub and the vine.

Asian bittersweet is very common at Mountain Lakes, identified in winter by its gray bark and large size. I had hoped to learn to distinguish it from native bittersweet before starting large scale removal, but it's likely that no native bittersweet remains in the park, or has lost any clear identity through hybridization with the exotic species.

Native Chestnuts in Princeton--the Next Generation

Many of us have lived our whole lives without seeing a mature native American chestnut tree. An excellent NY Times Magazine article described it as a true gift of nature, the perfect tree, growing straight and tall, with rot-resistant wood, and bearing nuts that were easily gathered and eaten, sustaining wildlife and people alike. My first encounter with the American chestnut was the sight of their fallen trunks in a Massachusetts forest, 70 years after the fungus that causes chestnut blight was discovered in NY city in 1904. The massive trunks I saw, lying on a slope in the shade of young white pine, were among the billions that the accidentally imported fungus would ultimately kill in the U.S. Since the roots survive the fungus, there was still a living community of underground chestnut trees beneath our feet in that Massachusetts forest. One of the roots had sent up a sprout about twenty feet tall--promising, one would like to think, but its slim trunk was already ringed by the fungus, its fate sealed before it could bear nuts. 

One of the projects I'm involved in is reintroducing native chestnuts to Princeton. The initiative began in 2009 with an email from Bill Sachs, a Princetonian with considerable expertise when it comes to nut-bearing trees. Bill reported that Sandra Anagnostakis, "one of (if not the) world’s leading experts on the pathology of American chestnut," had agreed to supply us with disease-resistant, hybrid American chestnut trees. Sandra's efforts to breed resistant native chestnuts at the Connecticut Agricultural Experiment Station over many decades was apparently unconnected to the American Chestnut Foundation. The trees were 15/16th native, and Bill with occasional help from me and others proceeded to plant them at the Princeton Battlefield, Harrison Street Park, the Textile Research Institute, Mountain Lakes and Herrontown Woods. 

Some fared better than others. Many, despite having been bred for resistance, nonetheless struggled with the blight that had laid the mighty tree low a century ago. This fall, however, paralleling our work to bring back native butternuts, one of the chestnut trees has borne fertile seeds.  

Bill made repeat visits to the tree to collect the nuts as they ripened. The deer likely got many, but he managed to gather quite a few, some of which he encouraged me to cold stratify. Stratification has always been an intimidating concept for me, suggesting sophisticated manipulation to get a seed to germinate, but in this case it turned out to be not much more than stuffing some seeds in a bag of moist peat moss and leaving it in the back of the refrigerator for awhile. 

The tree, hosted by TRI near Carnegie Lake in eastern Princeton, bore generously despite significant pruning by the periodical cicadas early in the growing season. 

This past summer a friend had sent me a photo of another chestnut tree that, being smaller, was much more affected by the cicadas' egg-laying activities. They cut into stems to lay their eggs, which ends up killing the foot or two of stem beyond where the eggs are deposited. 

We'll see how these various trees do over time, and if a second generation of these mostly native chestnuts comes into being. The NY Times article was mostly about efforts to develop a blight-resistant American chestnut through genetic modification. That thirty year project, with a geneticist named William Powell as the main protagonist, has been successful. They managed to find a gene in wheat that confers resistance when inserted into the chestnut's genome. 

Adding one gene would seem a much more precise and less intrusive means of correcting a century old wrong than adding many genes, most of which are irrelevant to improving resistance, from asian chestnuts. But don't expect these ever so slightly and efficiently modified native chestnuts to be available any time soon. There are strict regulatory hurdles that must be overcome. 

For me, the situation demonstrates two powerful forces in the human world. One is the fear of the slippery slope. Would an elegant genetic fix for the American chestnut open the doors to a wave of less admirable genetic modifications of our world? The other powerful force is our focus on regulating intentional change, while allowing unintentional change to run rampant. While the government spends years deliberating over one gene being added to the native chestnut tree, global trade is introducing an ongoing wave of new organisms to the country, any one of which could be the next emerald ash borer or spotted lanternfly. 

In the meantime, we'll be thankful for the mostly native chestnuts we have, and see what we can grow.

Below is more info I've taken from some of Bill Sachs' emails. Click on Read More. 

Tent Caterpillars and the History of Black Cherry Trees in Herrontown Woods

Black cherry trees draw attention in early spring because of the "tents" that tent caterpillars weave on them. I was surprised to find out that these tents are sometimes mistaken for gypsy moth infestations. There's also some disagreement as to how damaging tent caterpillars are to the trees they feast upon, so I decided to do some investigation. 

First, some distinctions between tent caterpillars and gypsy moths. Tent caterpillars are native, feed primarily on cherry trees, build conspicuous tents, and do their feeding on the fresh, tender leaves just beginning to emerge in April. Gypsy moths are a nonnative species imported from Europe, start feeding in May on a very wide spectrum of hardwoods and even some conifers, and do not build tents. 

Gypsy Moths

The story of gypsy moths in our area is most easily grasped by looking at how many articles about them have been archived in the Papers of Princeton through the decades. Outbreaks of gypsy moths remained minor in New Jersey until the 60s, then grew into massive defoliations of forests in the 1970s. By the early 1980s, gypsy moth populations were beginning to drop, thanks to a natural virus, introduced parasites, and aerial sprayings. A naturally occurring bacteria called Btk proved safe and effective when sprayed on trees where gypsy moths were feeding. There was a recurrence from 2007-8, but numbers have dropped off since then. Though the forests largely healed, the trauma of past gypsy moth infestations lives on in people's memories. 

Tent Caterpillars

What we have this spring, and springs extending back through millenia, are native tent caterpillars making their tents. 

Some sources on the web suggest that tent caterpillars, despite the powerful visual of the tents and defoliated branches, don't do enough damage to a tree to worry about. I'd really like to believe that, but this young black cherry tree, now bearing eleven tents from which the caterpillars make forays, is almost completely defoliated. 

They say a tree can survive one complete defoliation, but if defoliated several years in a row, it becomes increasingly susceptible to disease and insect attack.

Meanwhile, our very hungry tent caterpillars have even followed a branch over to a neighboring pin oak, which now, too, is getting chowed down upon.

We pause to note a couple recurring themes in nature. One is that the tent caterpillars will shift to a less desirable food source (a pin oak tree) if their favored cherry tree leaves run out. Deer, too, will begin eating less desirable foliage if they run out of their favorites. Thus, an overabundance of deer in the 1990s almost wiped out spicebush in our Princeton woodlands, despite it being low on the list of deer's preferred foods.

The other example of a recurring theme in nature is that the tent caterpillar eats only one crop of leaves, then is done for the year, allowing the tree to recover. The worst thing a predator could do is be so effective as to eliminate its prey. 

The introduction of a new insect, though, could throw off this balance of predator and prey. If another insect, say, a gypsy moth, came along and defoliated the same tree yet again in the same growing season, that tree would be in big trouble, having twice committed energy to manufacturing a whole crop of leaves, only to have them eaten. One question is whether the gypsy moth outbreaks in the '70s and '80s killed more of one tree species than another, causing changes in forest composition still noticeable today.

There's a lot of caterpillar behavior whose purpose is not immediately obvious. A week ago, caterpillars were crawling about on the outside of the tent, turning this way and that. My best guess was that they were expanding the tent by adding another layer of silk, but no strands could be seen coming from their bodies as they moved about. 

And why are these caterpillars clustered on the side of the tree, outside of their protective tents? Wouldn't they be easy picking for the birds that are said to consume them? 

As their spring residency has continued at the Barden in Herrontown Woods, the tent caterpillars have spun not only isolated tents but also enveloped the trunk and limbs in a silken web reminiscent of the webbing people drape on their shrubs for Halloween. A closer look reveals that the caterpillars have spun silken highways upon which they commute from tent to the "pasture" of the canopy. These highways are only one lane wide, requiring a caterpillar to temporarily step aside if it meets another coming the opposite direction. Some silken highways are suspended in air, like overpasses--a great way to smooth out the rough terrain of a black cherry tree's "black potato chip" bark. 

A tree colonized by tent caterpillars, then, has elements of occupancy, transport, and exploitation not unlike the human footprint on the land, with our homes, highways, and farm fields. A big difference being that the tent caterpillar's settlement is seasonal--more like the impact of nomadic tribes than our permanent villages--giving the tree a chance to recover.

Another big difference between tent caterpillars and other builders of shelters--bees, ants, birds, mice, people--is that the caterpillars don't seem to bring anything back to the shelter other than their bigger, well-fed selves. They aren't adults bringing food back to the young. The caterpillars, like super resourceful babies, work collectively to raise themselves, then leave the tree on their own to pupate and turn into adult moths.

Surprisingly, the subject of wild cherry trees in what is now the Barden (formerly a pine plantation) came up more than 50 years ago, in Richard J. Kramer's book about Herrontown Woods. 

"Wild black cherry, which grows to magnificent size in the Allegheny Mountains, is a poorly formed tree in Herrontown Woods, occurring mostly in areas which were recently open fields. Its best growth has been in the pine plantation, where specimens are 30 to 40 feet tall and possibly may develop into good-sized trees. Apparently these black cherries were able to develop along with the young pines after these were planted in the open field. Although the birds do bring seeds of the cherry into the forest, the many seedlings and the few saplings that occur there grow poorly and remain shrub-like."

Gone now are most of the pine trees in the pine plantation, and those larger cherry trees are nowhere to be found. Our 12 little black cherry trees in the Barden, all saddled with tent caterpillars, must be the descendants of the larger cherry trees Kramer describes. Only one large black cherry tree is known to exist now in Herrontown Woods, almost completely free of tent caterpillars, growing next to Veblen House. Have tent caterpillars contributed to keeping the black cherry trees of Herrontown Woods from achieving full size, in the past as well as in the present?

If we wanted to relieve the cherry trees of the spring burden of hungry caterpillars, we could remove the tents and remember to crush the egg masses laid by adult moths on small branches in late summer, as suggested in this useful post about the insect. 

But as insect numbers continue to decline, the role of trees as food for native insects grows in importance. And if the cherry trees remain small, that will allow more sunlight to reach the many wildflowers growing in the Barden. Leaving the tent caterpillars to grow undisturbed can serve as an experiment, to see if they continue to flourish year after year, or if nature's array of predators, pathogens, and parasitoids finally up their game and reduce the burden these trees now bear.