New Floral Finds on the Hoosic Shore

When my Thursday Naturalist friends and I semi-annually visit Canal Park in Rensselaer County, we usually  confine our searches to the woods along the high banks of the Champlain Canal and the Hoosic River, as well as a rich alluvial plain where some of our native plants like Green Dragon, Giant Ragweed, and Joe Pye Weed grow to prodigious size.  But as a group, we have never ventured out on the low rocky shore of the Hoosic as it approaches its junction with the Hudson River downstream.  Some of our friends might find it too risky to navigate the irregularly eroded jagged shale, or hop across puddles slippery with silt.  But my friend Ruth Brooks and I took our chances on this somewhat daunting terrain last Thursday, curious to see what we might find in this previously unexplored territory.

Last September, Ruth and I had found the exceedingly rare Provancher's Fleabane thriving in abundant numbers at this same location, with over 200 specimens growing directly out of the steep shale cliffs.  So we were initially startled to see flowering fleabanes growing at the same location so soon in the year.  But since it seemed much too early for these flowering plants to be that rare species, we surmised that these must be Philadelphia Fleabane (Erigeron philadelphicus var. philadelphicus), another native fleabane that is as exceedingly common as the Provancher's Fleabane is rare.  [Provancher's Fleabane (Erigeron philadelphicus var. provancheri) is rated as an Endangered species (S1) in New York State. It has been found only on exposed high-pH rocky ledges along rivers.]

UPDATE: As it turns out, these short fleabanes actually ARE the super-rare Provancher's Fleabane.  A week later, a rare-plant monitor from the New York Natural Heritage Program asked me to show him these plants, which he careful measured and analyzed.   Eventually, he determined them to be the Provancher's variety instead of the much more common Philadelphia Fleabane.   Big surprise!

There is another rare plant besides Provancher's Fleabane that grows along these shale banks, called Creeping Bushclover (Lespedeza repens), which is listed as a Rare plant (S3) in New York State. We had found it here last September when its trailing stems were full of bright-purple flower clusters.  Here's what those flowers had looked like back then:

Of course, it was much too early in the summer for us to expect to find those flowers in bloom, but we did recognize Creeping Bushclover's sprawling stems and three-parted leaves even without the flowers. We were happy to see that this large mat of trailing stems was at least as extensive as it was last year, if not even larger.

It amazes me to find so many flowers capable of growing directly out of these steep banks of jagged shale. The fine-stemmed, purple-flowered Harebell (Campanula rotundifolia) is surely one of the prettiest, its delicate appearance contrasting so strongly with the ruggedness of the rock.

But the Carolina Rose (Rosa carolina) rivals all other flowers here for beauty, and it certainly out-competes them all for fragrance!  There were masses of them clinging to the bare rock, and the riverside breeze carried their sun-warmed fragrance to us with every breath we took. This is a low-growing native rose that can be distinguished from the similar Virginia Rose by its large pink flowers that grow singly instead of in small clusters.

Among the several native shrubs that cling to these cliffs, this native Bush Honeysuckle (Diervilla lonicera) caught our eye because of the pretty yellow flowers that grew at the end of each branch.

We were not surprised to find White Beardtongue (Penstemon digitalis) here, since many plants of it grow in the low banks along the nearby Champlain Canal.  When our Thursday Naturalist group was here just a week before, the plants had borne only buds, but today those buds had opened to reveal the furry style that no doubt had suggested this plant's vernacular name of "beardtongue".  The flowers' similarity to those of Foxglove also suggested both this plant's scientific name and its alternate vernacular name of Foxglove Beardtongue.

Finally, here was a plant that I believe none of us had ever encountered here at Canal Park, the prettily purple-tinged flower called Hairy Beardtongue (Penstemon hirsutus). The flowers are indeed hairy, but an even more immediately apparent distinguishing feature is the way the flower tubes abruptly narrow as they approach the calyx.  

Our Thursday group has kept a record of all the plants we have found at Canal Park, and I don't believe this species has been recorded by our group as yet. But today, we found just scads of them out here on the shaley shore. So I am going to sign off now, and then send a link to this post to my friends in the Thursday Naturalists so the record can be updated.