Sunday, September 12, 2021

Walking Where Two Rivers Meet

Rensselaer County, NY:  Some places are so rich in wonderments that I feel drawn to return to them several times each year.  Canal Park at Lock 4 of the Hudson River/Champlain Canal is just such a place.  Here, the canal bypasses the Hudson rapids at Stillwater and rejoins the main river right where the Hoosic River flows into the Hudson from the east.  All that watery shoreline, steep shale banks, surrounding forest, and alluvial plain provide habitat for a rich variety of native plants, and easily accessed trails follow the waterways and wend through the woods.  And for those who have little interest in botanizing here, it's a beautiful spot just to picnic or walk, with the added feature of watching boats pass through the lock.

Birders, too, will find much to engage them along these shores.  Bald Eagles fish these waters and perch in the trees, while Osprey keep watch from a high nest.  And the day last week that my friend Ruth and I came here,  we were treated to the sight of this gorgeous Great Egret flying in to wade in the shallows of a canal backwater. Great Blue Herons are a common sight here, but an egret is a much rarer visitor.

At the point where the Hoosic meets the Hudson,  tall native grasses wave in the breeze. This particular grass is called Turkey Foot,  because its inflorescence is divided into long slender "toes", resembling those on the foot of a large bird. This grass is also known as Big Bluestem, and its scientific name is Andropogon gerardii.  At least two other tall native grasses, Indian Grass and Switch Grass, share this open sunny spot.  Note how brown the water is, as a result of several torrential rainstorms that occurred recently and filled our local rivers to their brinks and above.

At this site, we always search through the grasses for a low sprawling plant called Creeping Bush Clover (Lespedeza repens), classified as a Rare species in New York State. It is not a rare plant at this site, however, and we were happy to find a patch that still held a few blooming flowers, even though the plants themselves appeared to have been battered by recent rushing floodwaters.

Other riverside flowering plants seemed not to have been damaged by flooding, as this beautiful patch of Nodding Bur Marigold (Bidens cernua) demonstrates.

A  related species, called Common Beggar Ticks (Bidens frondosa) was blooming nearby.  This plant can be distinguished from some other beggar ticks by its three-parted leaves and the abundant sepals surrounding its ray-less flowers. These flowers appeared to be well on their way to producing the barbed seeds ("ticks") that will cling to any passerby.

We had to look closely to find these tiny flowers, a native wildflower called Whorled Milkwort.  Possessing alternate leaves as well as whorled ones, these plants would be the variety ambiguaPolygala verticillata var. ambigua.  Some taxonomists place this plant in its own separate species, however, calling it Alternate Milkwort (P. ambigua).

The flowers of any spurge species always deserve a closer look, so remarkable is their shape. That is certainly the case with these flowers of Upright Spurge (Euphorbia nutans), a native spurge that we found springing up from the naked shale at this point where the two rivers merge. The inflorescence consists of a small "cyathium" on a straight pedicel. Usually, several cyathia develop near the ends of each major stem when a plant is mature. A cyathium is a small cup-like structure containing the pistillate flower and one or more staminate flowers, which have neither true petals nor sepals. It is initially green, but often turns red in bright sunlight. On this particular species, the cyathia have four tiny petal-like appendages that are bright white.  Very pretty!

For beauty, our native New England Aster (Symphyotrichum novae-angliae) would be hard to beat, with its big vividly purple flowers.  Although this gorgeous wildflower is blooming abundantly along roadsides now, we were happy to find just this one single plant on the sandy shore along the canal.

We found other native asters, though, as we turned up the trail that took us along banks that rose high above the rushing waters of the Hoosic River.  This is  Stiff Aster (Ionactis linariifolia), a flower that tolerates some, but not dense, shade, and can grow in very thin soils that lie over nearly bare bedrock.  This aster species is unmistakeable if you handle the slender leaves and discover them to be almost as rough as sandpaper.

We had left the sunny open shore and entered a trail that was shaded by oaks and birches as it followed the Hoosic upstream.  This kind of habitat is one my friend Ruth finds especially exciting, since she has a great interest in mosses, and a shady forest is a fine place to look for mosses.

A shady forest is a pretty good place to look for fungi, too. I was particularly struck by the colorful beauty of this ruffly "pretty-maids-all-in-a-row" line of Stereum fungus following the curve of a fallen limb that was resting atop a lush green patch of Big Redstem Moss (Pleurozium  schreberi).

Another beautiful fungus (possibly an Amanita species) standing tall at the base of a tree and surrounded by a starry carpet of Haircap Moss (Polytrichum sp.).

Some very tiny fungi here, with wiry-stemmed  Marasmius capellaris sprouting atop fallen oak leaves, and the wee orange threads of the jelly fungus Calocera cornea protruding from holes in the bark of a decaying fallen twig. If either of these miniature fungi has a common name, I do not know what it is. The tallest of the Marasmius fungi was maybe 3/4 of an inch.

This shady woods is the only place I know of to find Deerberry shrubs (Vaccinium stamineum), and we were hoping to find its beautiful aqua-colored fruits.  We did find some fruits, but they were still bright shiny green and had not yet developed the bluish bloom they will acquire when ripe.  We could already detect the tiny dots that decorate each berry, though.  As beautiful as these berries will be when ripe, they are not very tasty and are best left for the wildlife to eat.

The new fruits of Wintergreen plants (Gaultheria procumbens) were starting to turn their vivid scarlet, but I thought these interim-pink berries were quite pretty in their own right.

I was delighted to find a patch of Pussytoes (Antennaria sp.), the frosted-green, ground-hugging leafy rosettes just as pretty past-bloom as they had been when bearing their long-stemmed furry flowers last spring. If I hadn't known better, I might have thought they were blooming now, with small gray-green rose-like flowers at the center of each leafy rosette.  But these flowery-looking growths are galls, not flowers, each one serving as a nursery bed for the larva of the insect -- a species of midge -- that laid her egg on the plant.

Although the function of a gall is to provide a safe and nourishing space for one insect's egg and developing larva, competing insects (usually wasps) often invade the gall, either to devour the egg or larva within or to lay their own eggs that will produce their own larvae to parasitize the original larva. It appears that one of these galls (the second from left) has been rifled by another invader (a bird or a rodent, perhaps?) looking for an easy meal.

When our forested trail descended to a flood plain we had hoped to explore, we were startled to see just how high the river had risen and how rowdy and roiling its waters were flowing.  Normally, that gnarly old Silver Maple tree stands well back from the water's edge, and we can easily make our way along a sandy, shaley shore to find lots of riparian species of plants. Not today!

Most of the plants we had hoped to find in this floodplain were flattened by flooding waters, and worse, we were horrified to find heaps of the terribly invasive Water Chestnut deposited here when the height of the flooding receded. Since this scourge of a plant grows in standing water, I guess we can hope that it won't take root on the muddy shore.

Dozens and dozens of the native Green Dragon plant (Arisaema dracontium) grow at this site, but of course all the giant-sized plants had been flattened by the floods.  But the gorgeous clusters of shiny red berries were easy to spot among all the rest of the floral wreckage. This is a plant well-adapted to occasional flooding, and in fact, it will probably take advantage of all this flowing water to spread its seeds.


The Furry Gnome said...

I'm going to look up the Hoosic River and see where that is.

The Furry Gnome said...

Found it!

threecollie said...

The high water this summer has been a source of endless frustration for all of us birders too. No visiting shorebirds to get all giddy over. We went to the plant sale at the George Landis Arboretum yesterday and I fell in love with what I think is called Clover Bush. It was so pretty and just buzzing with bees and other insects. As always this is an interesting and informative post.