Some Native White Flowers of June

Arrowood Viburnum (V. dentatum)

Virginia sweetspire (Itea virginica)

A new one in the yard, and on this blog: foxglove beardtongue (Penstemon digitalis)

Elderberry at the Princeton High School ecolab wetland

What's Not To Like?

A native vine shows its pretty fall foliage on a snag next to the parking lot.

Radiant colors, a feast for the eye,

and berries for the birds!

What's not to like?




Hint: Leaves of three.

Stalking Monarchs, and Encountering the Other Milkweed Caterpillar

Note: This post serves as a contrast to the horrific flooding in Houston from Hurricane Harvey, showing how stormwater can drive diversity rather than destruction, if we work with nature rather than against it. Unlike cities, the plants that grow in floodplains are built to pop back up within days or hours after a flood and just keep on growing and flowering. Most of these photos were taken in a detention basin, which is an acre-sized depression in the ground, dug to receive storm runoff from the Smoyer Park parking lot. The purpose is to "detain" the rain that hits the asphalt and that would otherwise rush into the nearby stream. Detaining the water reduces flooding in downstream neighborhoods. The detained water then either seeps into the ground or is slowly released through a small pipe into the stream after the floods have receded. 

Last year, a collaboration of federal and local governments with the Friends of Herrontown Woods converted this mowed basin into a wet meadow with floodplain plant species that thrive with these periodic pulses of runoff. Without regulations requiring it, the concave setting for this lovely oasis for native plants and pollinators would not exist, and the polluted runoff from the parking lot would have flowed straight into the local stream, contributing to flash floods.

Nature has offered up some surprises, here in the doldrums of summer, when people who aren't somewhere else sometimes feel like they should be. There was the unexpected, and unexpectedly affecting, chance to capture family portraits of black vultures in the previous posts; the weather has been unexpectedly cool; rains have come when needed for the third year in a row, and monarchs have proved resilient, rebounding from their diminishing numbers in recent years. Not many, as yet, but more.

Thinking them elusive creatures, I figured a zoom lens was necessary to capture their image. First came a peekaboo shot on the far side of a thistle at the Smoyer Park detention basin that we converted last year to (mostly) native meadow.

The blooms of Indian grass got pleasantly in the way of this shot.

With nowhere else to go in a sea of soccer and baseball fields, the monarch kept circling around the planted meadow, encouraging patient waiting for a chance at an unobstructed view. Finally, a clear shot from 100 feet away, while it perched briefly on a river birch. Congratulating myself on some success with a powerful camera, I plunged into the meadow to weed out a small clump of foxtail grass that would become way too numerous if allowed to go to seed.

And there, five feet away from my tugging and clipping, landed the monarch, easily photographed with an iPhone,

with a coppery background of Indian grass. That's what weeding a wild garden does--it immerses the gardener, creating opportunities for serendipity to work its magic.

Just across Snowden Lane from the park, behind Veblen House where our Friends of Herrontown Woods group has fashioned a clearing by removing invasive shrubs and wisteria, another sort of caterpillar munched on the leaves of common milkweed, which has prospered in the resulting sunlight.

Displaying proper Princeton colors, the milkweed tiger moth needed every milkweed plant there, and then some. We came back a week later and found every milkweed stripped down to bare stems. The common milkweed's strategy of aggressive underground spreading becomes more understandable, given the voracious appetites of these caterpillars.

Also called the milkweed tussock moth, the caterpillars become more colorful as they grow. As an adult moth, they are said to retain the cardiac glycosides they pick up from eating milkweed, and warn bats of their unpalatability by emitting a click as they fly about at night.

With summer almost over, a first sighting of a monarch larvae--on a purple milkweed, of which there are very few in Princeton, for some reason. Common milkweed can be a bit too aggressive in a garden, and swamp milkweed disappeared from our garden after a few years. Purple milkweed with its showy blooms may be a good alternative, if we can find any seed after the hungry caterpillar is done.

Hi Time For Hibiscus

Well, hello there, beautiful. The Hibiscus that's native around here, Hibiscus moscheutos, or rose mallow, is as tough as it is beautiful, thriving along the edges of Carnegie Lake and lining the wetlands of the upper Millstone River, up West Windsor way. Gather seeds from the convenient packaging of its capsules in the fall, and you might end up with some in a wet, sunny spot in the backyard, which is how I know that kayaking up the Millstone River from Carnegie Lake might be particularly lovely right about now.

As part of the Detention Basin Enhancement Program, which did not officially exist until the words were typed a few seconds ago, I took some of its copious seedlings from my backyard and pressed them into the ground at Smoyer Park yesterday evening, as the thunderstorm approached. Combining the planting with weeding, I pulled up a horseweed or pilewort, pressed the Hibiscus root into the resulting hole, then lay the pulled weed gently over top of the Hibiscus, to shade it while its roots take hold. Improvised, but potentially effective.

Other members of the Hibiscus genus get into the act this time of year. Rose of Sharon (Hibiscus syriacus) can stand alone as a large shrub, or grow vertically enough to be a hedge. Not native, it tends to spread by seed in the yard, but hasn't made the leap to wilder areas that I know of.

There were big-flowered Hibiscus in my sister's garden in Cleveland that looked like this. It's a cultivar, and I resist calling it the same species as the local Rose Mallow, but am finding no other scientific name on the web.

Other dramatic native Hibiscus, not seen growing naturally around here, are H. coccineus (Texas Star Hibiscus) and H. laevis.



Update: A week or so later, Flower of an Hour (Hibiscus trionum), an Old World weed, showed up along our curb. Went back maybe an hour later, and the flower had already closed.

The Incredible Whiteness of Early Summer Flowers

Count the ways a flower can be white in early summer:

A white version of obedient plant in a frontyard raingarden fed by water from the roof,

The first summer bloom of rose mallow hibiscus in a backyard swale fed by water from the uphill neighbors,

boneset getting ready to pop,

Culver's root,

some elderberry flowers late to the party, growing next to the chicken coop,

pokeweed,

tall meadowrue,

lizard's tail,

bottlebrush buckeye,

black cohosh up among the boulders on the Princeton ridge,

buttonbush and

oakleaved hydrangia, both growing in front of the Whole Earth Center,

Yucca filamentosa in a neighbor's front yard,

and, at Westminster's parking lot raingardens, some unintended white clover,

catnip,

and Queen Anne's lace.

These last three on nonnative; the rest are native to the eastern U.S.

Lonely PawPaw Seeks Cross-Pollination

Round about Mother's Day, my friend Karla received this email: "Lonely apple tree seeks similar for discreet short-term relationship. Afternoons preferred." Just in case there was any misunderstanding, some explanatory text was added: "My tree is blooming, for the first time; is yours? If so, can our trees make a date? Warm regards."

As it happened, her husband Steven was headed that very day to South Brunswick on a related mission, in search of pollen to satisfy the fruiting needs of another kind of fruit tree, the solitary pawpaw planted in their backyard some years ago that was now in full bloom. Though it had sprouted an additional trunk, it was still lonely, genetically speaking, and unlikely to set fruit unless visited by pollen from another pawpaw patch.

Thrust into the role of pollinator, Steven found himself at a distinct disadvantage. He had neither the wings to search the greater Princeton area for other pawpaw trees, nor sufficient olfactory apparatus to detect the subtle carrion-like odor pawpaw flowers use to attract pollinating flies. And since Google Maps does not (yet) provide directions to New Jersey's pawpaw patches, the search for prospective pawpaw mates required considerable research savvy. Even upon arrival at the best prospect he could find, the orchards at Rutgers, he still required the kindness of strangers to find the pawpaws amongst all the other fruit trees in the no-doubt vast plantings at Cook College.

This sort of matchmaking is becoming more common as the local food movement, perhaps abetted by backyards made sunnier by tree-toppling storms in recent years, prompts the planting of solitary fruit trees in cloistered backyards--peaches, apples, cherries, figs, persimmons, pears, and the occasional pawpaw--all with uncertain prospects for leading a healthy, promiscuous life of cross-pollination.

For those who know pawpaws only from the childhood lyric about a "pawpaw patch", they happen to be a native understory tree in the Annonaceae--a family of mostly tropical species. One relative of pawpaw grown by the Incas is touted as perhaps "the greatest fruit on the planet", with a taste combining mango and banana. Pawpaw, adapted to the north, offers a chance to grow tropical tastes in cold climes. Though delicious, its shelflife is short, which has thus far limited the pawpaw's commercial potential.

Thanks to the internet, I now know that the "way down yonder in the pawpaw patch" phrase that I've been carrying around in memory all these years comes from a boyscout song. I did not personally reach the status of boyscout, having earned my bobcat, wolf and bear badges in cubscouts only to lose momentum during a leadership void in that critical transition from cub to boyscout. The transition is called webelos, which stands for "we'll be loyal" scouts, a molting process that not everyone successfully completes.

If I had, I might have learned the complete lyrics for Pawpaw Patch, and known that "way down yonder in the pawpaw patch" answers the musical question "Where oh where oh where is Susie?" It matters where Susie is because she happens to be the "queen of Hawaii", which goes with the pawpaw's tropical family roots. If you ever go to Hawaii, you may encounter some of pawpaw's relatives, like the ylang ylang, soursop, and sugar apple. However, according to the song, you needn't go way down to Hawaii, because Susie will teach you to hulu way down yonder in the nearest pawpaw patch. If not completely distracted by Susie's hulu tutorials, the astute boyscout will note that "way down" and "patch" are descriptively correct, because the pawpaw tends to grow in rich bottomlands, and forms clones from its spreading roots.

There's another lingering pawpaw-related mystery knocking around in my memories. In my parents' Michigan backyard in the pre-internet 70s, a pawpaw sprang up spontaneously one year, grew into a patchlet of several stems, and after a few years began bearing flowers and a few fruit the size of a small mango. Where the pawpaw came from is a mystery, as was its capacity to bear fruit, because there was no known patch nearby, and the seeds looked much too large to navigate a bird's digestive tract. We didn't ask questions, however, because they were delicious. A bit of pollination assist with a cue tip may have helped with yield one year, which the raccoons and squirrels were grateful for.

Steven's recent research, empowered by the internet era, has delved far more deeply into the sexuality of a pawpaw. Way up yonder in this pawpaw post is a picture that Steven sent me of two pawpaw flowers, the green one not yet having acquired that lovely burgundy hue that flies are supposed to mistake for dead meat.

If a pawpaw flower were able to speak to its sexuality, it would say something like "I was female before I was male." Here to the left is a male flower, which is really a female flower a few days later. Looking closely, you can see a subtle difference. There are now yellow (male) anthers surrounding the green dot in the center (female stigma). The logic is that the anthers on any particular flower open up as the stigma is closing down, thereby preventing a flower from pollinating itself.

But that logic suggests that a tree with flowers in different phases could in fact pollinate itself, with pollen from one flower spreading to the next, and make fruit without importing pollen from elsewhere.

Still, the available information suggests that it helps to have cross pollination from one pawpaw patch to another, and that human-assisted pollination is often needed to make up for a lack of interest among the local flies.

Next year, Steven won't have to travel to South Brunswick in search of a "house of reputed pawpaws", because by chance I found a fine potential mate in the backyard of another friend, behind the Jewish center just a quarter mile away. It's a splendid specimen, thirty feet high, sporting perhaps a thousand flowers.

But pawpaw growers shouldn't have to depend on chance discovery. There needs to be an internet dating service for fruit trees. Sometimes it takes a village, or at least a good network.

Update, June 9: Just met a neighbor named Joe who has replaced the lawn in his side yard with four varieties of pawpaw and a lot of mulch. He says that wild pawpaws are common in Maryland, that raccoons and squirrels may be repelled by the bad-tasting skin of the fruit, and that it's easy to emerge from wild pawpaw patch with large buckets of fruit. I did not ask about any encounters with Susie, or if Marylanders are more adept at doing the hulu.


Some interesting links:

http://apiosinstitute.org/asimina-triloba-pawpaw

http://www.hort.purdue.edu/ext/ho-220.pdf

Will the Real Marsh Marigold Please Stand Up--a Confusion of Yellows

A lot of people call this flower "marsh marigold". It's not. Notice the leaves stay close to the ground, and the small flowers have many petals. This plant is actually Lesser Celandine, a pretty but highly invasive exotic plant that will spread across lawns and coat floodplains in what looks like green pavement. I found this one specimen in my yard, and because there was only one, I was able to dig it up, hopefully before any seeds were produced, put it in a plastic bag, and threw it in the trash, not the compost.

(Update: Most homeowners don't notice lesser celandine, also called fig buttercup or Ficaria verna, until there are too many to dig. Digging also requires getting every last tuber in the roots. Oftentimes, the only practical option is to use a targeted dose of herbicide. Though herbicides are demonized due to their overuse in agriculture, the selective use of low-toxicity herbicides is an important part of invasive species control, just as low-toxicity medicines are selectively used in medicine. I use a 2% wetland-safe version of glyphosate, which can be bought from companies other than Monsanto.)

The real marsh marigold, shown here, is a native with five-petaled flowers, stands more upright, and is so rare that I've only seen it growing wild once in my life. These particular plants are in my backyard, purchased from Pinelands Nursery in Columbus, NJ. I also planted some at the Princeton High School Ecolab Wetland that are in full bloom right now.

The flower and leaf of marsh marigold (Caltha palustris) are on the left, with lesser celandaine (Ranunculus ficaria) on the right.

Dandelions blooming now can make it harder to tell if you have lesser celandine in your yard.

Adding to the confusion of yellow this time of year is the Celandine Poppy (Stylophorum diphyllum), a native in the poppy family that was common in the University of Michigan arboretum, but seldom seen elsewhere. A friend in Princeton gave me some, and it has seeded into the flower bed of my backyard. Like the marsh marigold, its rareness in the field bears no relation to its willingness to grow when planted in the backyard.

The "Second Forest"

This is a good time to see the "second forest"--the layer of exotic shrubs underlying the native tree canopy. Honeysuckle, multiflora rose and privet, having evolved on other continents and under different climate constraints, all leaf out earlier than the native species.

Historically, an eastern forest would have been carpeted with spring ephemeral wildflowers of great variety, flowering and collecting another year's energy stores before the trees leaf out and grab all the sunlight. The exotic shrubs throw a wrench into the works, leafing out early and shading the native wildflowers before they have a chance to store enough solar energy for the next year.

Shadbush and the Shad Run

The fishermen at Princeton township's Pettoranello Gardens are at loose ends these days. Ever since someone stole their fishing rods, life just hasn't been the same. This time of year, I bet they're wondering if the shad have started their spring run up the Delaware River to spawn.

That's easy enough to tell, even if your island doesn't come with an internet connection. Just take a look around to see if the shadbush is in bloom.

Shadbush, also called serviceberry, is in the Amelanchier genus. Though native, they're hard to find around here in the wild. I cut a bunch of stems off this one before moving it to a sunnier spot in my backyard, and stuck them in water like one would do with forsythia. The berries are tasty, depending on the cultivar. The one in my yard is a wild, unbred variety purchased years back at Pinelands Nursery, a wholesaler 20 miles from Princeton. Maybe it will produce better berries in full sun.

The rainbows in the photos, by the way, are generated by our home's powerful solar array, which drives duel prisms capable of generating enough rainbows to supply 100 living rooms with good luck.