Sunday on the River With Sue

I had planned to be up on Whiteface Mountain this weekend, but vision problems that would make it hard to find my way around unfamiliar areas kept me home, regretting my chance to explore the alpine flora on top of that Adirondack high peak.  But I didn't feel sorry for myself for long, once my friend Sue and I launched our boats on the quiet backwater above the Glens Falls dam today.  Here is familiar territory I know very well, but I never grow tired of its loveliness and abundance of fascinating riparian flora .

The weather was even more pleasant than we had expected it to be, with bright sunshine and calm winds that made paddling a dream, and which also enticed many turtles to emerge from the depths to bask on fallen logs.

That small yellow flower lifting its head above the water in the foreground of the photo above is one of the rarities that thrive in this quiet backwater.  This is Small Floating Bladderwort (Utricularia radiata), listed as a "Threatened" plant in the state but very happily at home in this stretch of the Hudson River.  This area above the Glens Falls Dam is where I first saw and identified it several years ago, but I have since found it as far upstream as the catchment between the Spier Falls and Sherman Island dams at Moreau.  Since it floats freely along on those inflated "pontoons,"  it is free to move wherever the current carries it, so who knows where else it may be found?

As with all bladderworts, U. radiata possesses underwater structures containing tiny bladders capable of sucking in and digesting minute organisms that live in the water.  These structures are visible surrounding the plant in the photo above.



These quiet waters are also home to another plant considered to be rare in New York, the Water Marigold (Bidens beckii).  Although it was not yet bearing its pretty yellow flowers, we could see its emergent leaves protruding above the water along one shore.  Like many plants that grow in water, its underwater leaves appear quite different from its emergent ones.

We were delighted to find the ubiquitous Water Shield (Brasenia schreberi) blooming today, holding its pinkish flowers well above its oval floating leaves.  This flower has no petals, but its shiny sepals curl back very prettily.  Although the flowers contain both staminate and pistillate parts, only one sex ripens at a time.  In the photo below, the stamens have developed pollen-bearing anthers, while the pistillate parts in the center remain closed and unreceptive.

After the anthers have shed their pollen, the stem will retract the flower underwater until the pistillate parts are ripe, and then the flower will re-emerge with pistils arrayed and ready to receive pollen from other plants, as demonstrated by the flower in the photo below.

Water Celery (Vallisneria americana) is another water plant with an interesting sex life.  We could see the female flowers floating on the surface of the water today, but I doubt we will ever see the male flowers, they are so small.  The female flowers are held on curly stems that relax or retract in order that the flowers sit exactly within a dimple at the surface.  The male flowers form at the base of the plant at the bottom of the river, rising to the surface when ripe and floating along until they fall into the female flower and accomplish pollination.  After pollination, the stem retracts sharply and deposits the fertilized flower in the mud, where it will produce a new plant.

Fragrant Water Lilies (Nymphaea odorata) will also retract below the water's surface as soon as they are pollinated.   This is why we never see any Water Lilies that are shriveled or brown, but always perfectly gorgeous, as were those that were floating on the water today.

Since Sue and I discovered a large population of Wild Senna (Senna hebecarpa) here on a backwater island, we always look for it every year.  We thought we might be a little late to catch it in bloom today, but no, there were still several plants with large showy clusters of bright-yellow blooms.

After leisurely exploring the quiet backwater, Sue and I headed out to the open river to paddle upstream toward steep shale cliffs that lie just below the Feeder Dam.  On our way, we found this delightful little garden of mini-plants tucked into some fallen logs.  On the left is Dwarf St. Johnswort (Hypericum mutilum), on the right is Golden Pert (Gratiola aurea), and barely visible behind is Small Bedstraw (Galium trifidum).

The north-facing shale cliffs rise very steeply from the water's edge, and they are continually dampened by springs dripping down from above. creating a dark and cool environment for a number of interesting plants to grow.

The presence of Bulblet Fern (Cystopteris bulbifera) indicates the presence of lime in these cliffs, for this is a fern that only grows on calcareous substrates.  Their long curvaceous fronds make for a lovely display, especially when flowering shrubs of Spikenard (Aralia racemosa) are added to the mix.

The dainty-flowered Kalm's Lobelia (Lobelia kalmii) clings to these vertical cliffs, and the plants almost always seem to be anchored by underlying patches of liverwort.

Here's a closer look at those lovely lobelias, backed by a cluster of Grass-of-Parnassus leaves.

As these budding stalks reveal, it won't be long until these cliffs are covered with the beautiful white blooms of Grass-of-Parnassus (Parnassia glauca).

A number of Mountain Maples (Acer spicatum) grow out of these cliffs, and today they were adorned by clusters of rosy-winged seeds.

Several sections of the cliffs are splashed with bright-orange patches of Trentepohlia aurea, a green alga that contains a chemical that masks its chlorophyll.

Here's a closer look at that alga, the better to see its rather furry texture.

I was intrigued by the sight of many tiny tan balls dangling on filaments attached to the side of the cliffs.  I do believe these are the egg cases of a spider, but I do not know which species.  They were just one more fascinating find on this beautiful day for paddling the river.

Update:  I KNEW those egg sacs looked familiar, for I had posted a photo of them before and had sent my photo off to BugGuide.net and received an answer promptly.  This is indeed the egg sac of a spider, a ray spider called Theridiosoma gemmosum.  Ray spiders are known for creating cone-shaped webs.