Canal Park at Lock 4 of the Champlain Canal offers many delightful options to the nature lover seeking a fascinating place to explore. This park is located in Rensselaer County where the Hoosic River flows into the Hudson River's barge canal, and the two rivers present quite varied habitats, from moss-carpeted woodland trails along high shale banks to rich bottomlands where unusual plants grow to enormous size. And this year, near-drought conditions have created a third very interesting habitat: exposed river bottom, consisting either of water-carved rock or wide muddy flats. As it happens, I agreed to lead two group walks here recently, one this past Thursday for my friends in our Thursday Naturalists group, and the other to take place on September 6 for another group of naturalists from Schenectady. Since I cannot pause to take photos while leading a group, I took these photos when I previewed the trails last Wednesday.
Canal Park offers a large parking area right next to the lock, where porta-potties, picnic tables and grills offer picnicking conveniences to visitors. Some visitors stay by the lock to watch it operate to allow large or small water craft to navigate around the Hudson River's rapids. Our particular groups usually set off to explore the trails, often choosing to start on the shady woodland trail along the canal. As did I, on this preview walk.
The clanking and grinding of huge metal gates upstream alerted me that some kind of watercraft would shortly appear on the canal. And so it did, as this cabin cruiser came slowly making its way toward the main course of the Hudson River downstream.
This particular section of trail is carpeted with many different kinds of lush green mosses and lichens. Here, a pale green Reindeer Lichen shares its space with the star-burst leaves of Haircap Moss.
That same Haircap Moss (Polytrichum commune
) also grows intermixed with the red-stemmed moss called Big Red (Pleurozium schreberi
) in lush green patches.
This moss, called Windswept Broom Moss (Dicranum scoparium
), often looks as if its leaves had all been swept. The long slender stalks held this moss's spore capsules aloft, the better to catch a breeze to carry the spores away.
Few flowers bloom in the dense shade of this trail, but the delicate rosy-purple flowers of Slender Gerardia (Agalinis tenuifolia) are an exception.
I was quite excited to see these pale-aqua fruits dangling from the twigs of Deerberry shrubs (Vaccinium stamineum), since I had sought in vain to find any of its flowers back in May. These fruits maintain their pale aqua color even when fully ripe.
At first glance, one might think that these low-growing Pussytoe rosettes (Antennaria sp.) had sprouted tiny pale-green rose-shaped flowers. But no, these "blooms" are galls, not flowers, formed when an Everlasting Bud Midge laid her eggs on the plants, which responded by producing this rosebud-shaped plant tissue to surround and protect the developing larvae.
Since we did have some recent torrential rains, a few fungi had sprouted up along this shady trail. It looked as if this Red Russula mushroom had used that heavy rainfall to grow to prodigious size!
These tiny fragile mushrooms make up for their small size by being colored brightly enough to detect on the forest floor. If not for their orange color, we might never notice the tiny Marasmius siccus.
I do not know the name of these itty-bitty white mushrooms that had sprung from the slimy, rotting cap of a much larger mushroom, but I didn't need to know that name in order to be astounded by this very interesting fungal event.
I do not know the name of this developing fungus, either, just beginning to grow its "baby teeth" as it takes form from fuzzy white growths on a fallen twig. Is it a toothed fungus, like Milky Tooth, or will those "teeth" develop into maze-like gills? Maybe somebody can tell us, but I sure don't know!
As this woodland trail reaches the sunlit site where the Hoosic River joins the canal, I was surprised to see how low the water had fallen since I was last here in June. Back then, the water was flowing close to the trunk of that overleaning tree.
And of course, when there are muddy flats, masses of False Pimpernel (Lindernia dubia) often take the opportunity to spread across the mud.
Here's a closer look at one of those pretty pale-blue native wildflowers.
Another eager colonizer of mud flats is this species of aptly named Nodding Smartweed (Persicaria lapathifolia). Another vernacular name for this native wetland wildflower is Pale Smartweed, also an apt name for a plant with such pale blooms (which can also be pale pink). The "smartweed" name is also accurate, as can be proved by nibbling a leaf and experiencing how quickly your tongue then "smarts"!
Apparently, that biting quality of its leaves does not dissuade this Pearl Crescent Butterfly from tasting the Nodding Smartweed's nectar.
Before we made a sharp turn to follow the Hoosic River upstream, we searched a grassy area here on this point, hoping to spot the nearly invisible greenish-pink blooms of Whorled Milkwort (Polygala verticillata). Despite that "whorled" appellation, these tiny plants have some alternate leaves on their stems, indicating this is probably the variety ambigua.
As we start to follow the Hoosic River upstream, we are amazed to see how low the water has fallen, exposing much of the water-carved shale that constitutes this river's bottom. We easily could have crossed the river here, hopping from dry rock to dry rock, without even getting our feet wet.
After a woodland walk along high banks, we descended to a flat area just where the Hoosic bends, delivering silt-rich floodwaters that encourage the plants that grow in this alluvial soil to reach prodigious size. These Ostrich Ferns (Matteuccia struthiopteris), for example, grow nearly chest high, beneath towering Sycamores and Cottonwood trees.
This is the only place my friends and I have ever found Green Dragon (Arisaema dracontium) of any size, and here it grows hip high. The plants were still erect and readily visible now, although the long pencil-thin spathes had given "birth" to clusters of glossy green fruits attached to the sturdy stems. The fruits will later turn a brilliant scarlet, easily seen among the collapsing leaves.
Among the other wildflowers thriving on this sunlit shore, the deep-purple blooms of Monkeyflower (Mimulus ringens) were especially colorful.
The big, showy, bright-yellow blooms of Great St. John's Wort (Hypericum ascyron ssp. pyramidatum) have yielded some big showy seedpods now, and a large patch of this state-listed Rare native wildflower was easily spotted, leaning out from the thickly overgrown bank.
This pair of Turtleheads (Chelone glabra) was also easy to spot, their fat white flowers shown to best advantage agains the dark shale of the steep bank rising behind them.
Just downstream from the low floodplain site so full of wildflowers, the banks of the Hoosic rise steeply from the flat exposed river bottom. Those steep shale banks are home to some plants we rarely have access to, but which the lowered water level will allow us to approach this year.
I am always amazed by how a flower as delicate in appearance as Harebell (Campanula rotundifolia
) can grow in some of the ruggedest habitats. Here, the Harebell's long slender stems project horizontally from the steep rocks, holding the vibrantly purple flowers out closer to the sunlight.
These Provancher's Fleabane basal rosettes cling tightly to the vertical shale banks. The presence of such rosettes so late in the summer is a very strong clue that this particular variety of fleabane (Erigeron philadelphicus var. provancheri) is the Endangered variety, known from very few sites in New York. I found many fewer plants this year than the hundreds I found a year ago, possibly because of the lack of rainfall and hot temperatures this summer.
Because I took my preview walk at Canal Park in the afternoon, I was able to see many flowers starring the floating leaves of Water Stargrass (Heteranthera dubia), an aquatic species that was thriving in the shallow pools among the exposed flattened rocks of the Hoosic riverbottom. Since this flower appears to bloom only in the afternoon, my Thursday Naturalist friends could see very few of its bright-yellow blooms on our mid-morning walk.
Most of my Thursday friends also missed seeing these floating rafts of Water Chestnut leaves, since I ripped them up from the river and threw them high and dry on a hollow log to desiccate. This alien plant (Trapa natans is the scientific name) has become a terribly invasive species since it was inadvertently released in North American waters in the late 1800s.
As we considered our return walk, I suggested two different routes to my friends: either continue on a shady wooded loop that would lead to where we began, or choose the more difficult terrain of the exposed river bottom, mostly flattened shale but with occasional jagged areas that would pose a risk to the less sure-footed among us. Such an opportunity to explore a previously inaccessible site was tempting, but it also presented some danger.
I had easily walked this river-bottom route myself on the previous afternoon when the sun's direct rays had begun to relent, but on the mid-day my Thursday Naturalist friends considered this option, a hot sun was blazing down on this shade-less course. Since I had already explored this route, I offered to accompany any friends who chose not to risk this difficult terrain and wished to continue along a less arduous route. (Unfortunately, some chose unwisely, and we suffered some agonies of concern, but luckily, all finished the walk while still upright.)
Although Goldenrod is hardly a plant worth risking exhaustion to see, I hoped my friends might stop to marvel at how many Goldenrod Soldier Beetles used this particular plant (species unknown) as their love nest. I couldn't help musing when I saw them: these soldiers would rather "make love, not war"!
An even more fascinating visitor to these riverbank goldenrods was this species of tiny, dust-colored moths. Members of the Petrophila (rock-loving) group, they seek out the shores of fast-moving rock-lined rivers like the Hoosic to create their offspring in a most unusual way.
After mating, the female will hold an air bubble to her ventral surface as she descends an underwater rock face, there to deposit her eggs. The larvae that emerge will feed on the organisms coating the rocks before they create their double-walled silk pupation chambers, also on the rocks. The adult moths emerge from those pupation chambers to rise to the surface and fly away, to start the process all over again. Being otherwise engaged in assisting a struggling companion, I was unable to relate this incredible tale of scuba-diving moths to my friends who were walking this shore far ahead of me. Perhaps some will read about these amazing creatures here on my blog.
I also hope my friends were made aware of this large patch of Creeping Bushclover (Lespedeza repens) that thrives out here on a Hoosic River shore that in most years is inaccessible to us because of higher water. Judging from its abundance on this shore, it's hard to believe that this plant is rated as a Rare species in New York State.
Here's a closer look at the pretty pink flowers of Creeping Lespedeza.
As I completed this day's adventures, I was delighted to find a big beautiful Yellow Garden Spider (Argiope aurantia) arrayed on her zig-zag-adorned web. Females spin orb webs with a conspicuous white zigzag structure in the middle called the stablementum. Spider experts disagree about why these spiders spin stablementa. Earlier, this zig-zag structure was thought to give stability to the web. Now the thinking is that the stablementum attracts insects or keeps birds from flying through the web.
On the drive out of Canal Park, I noticed two Ospreys perched on the nest constructed atop a platform erected by the park. How odd, I thought, to see adult Ospreys still hanging around their nest, long after their offspring should have fledged. But then I remembered: the adult Ospreys leave the nest soon after their young have learned to fly and fish for themselves. But the young ones hang around for a while longer, eventually taking off for Central or South America sometime in September. Many times I have gazed at this nest, hoping to catch a glimpse of its inhabitants. How lucky for me, that I finally saw them, just before it was time for them to leave.