I failed to write about our foray last week, so I will add it to today's post. The 23rd was a short walk in the Ramble, not too many species seen.
The Oven is a nice birding spot in the Ramble just south-west of the Boathouse. There is a beautiful rock outcrop on which one can stand and look into a swampy wooded area and see some of the many species of birds that live in and migrate through the Park. We examined the plants growing in the cracks of the rocks and collected several specimens of the grass family (Poaceae).
Panic grass (Panicum sp.) and rosette grass (Dichanthelium sp.) are similar genera and used to both be classified as Panicum. Like all grasses, they have hollow stems and joints along the stem. The mnemonic "sedges have edges, rushes are round, grasses have knees all the way to the ground" helps to remember this characteristic.
Gleason and Cronquist's Manual of Vascular Plants* lists 48 Panicum species for the Northeast. This edition was written before Dicanthelium was split off. Daniel and I have collected 14 specimens in these two genera. Tune in to future posts when we determine which species we have. In the meantime, here is generally what the two genera look like.
We collected arrowwood viburnum (Viburnum dentatum) already, but today we saw a nice stand of it in fruit. The viburnums are shrubs with opposite leaves. Arrowwood is a native species with beautiful black fruit that is attractive to wildlife. The fruit contains a high percentage of fat which is an important energy source for migrating birds. It has always been a good restoration species for the Park as it grows easily and until recently had not serious pest problems. But the viburnum leaf beetle (Pyrrhalta viburni) showed up in the Park within the last 10 years and some of the shrubs have shown signs of beetle damage. Let's hope it does not decimate the populations of arrowwoods we have. Viburnums were formerly classified in the honeysuckle family (Caprifoliaceae), but have been moved to the Adoxaceae. The specific epithet (the second part of the scientific name) "dentatum" refers to the toothed margins of the leaves.
On the 30th we walked around the Reservoir. Daniel had seen a couple of species from prior lists but not yet collected by us and we have not seen those species elsewhere in the Park. Conservancy staff helped us with plants that were out of our reach. We are grateful to Maria Hernandez (Director of Horticulture), Bill Kearny (Reservoir Supervisor) and Andrea Gaskin (Reservoir Zone Gardener) for their help. Ken Chaya and Marie Winn joined us today.
The plants on the reservoir wall are a mix of wild plants and plants that have been seeded in by Conservancy staff. Woody material has to be kept off the wall to prevent damage, so herbaceous plants are encouraged to provide habitat for wildlife.
The first species we collected was lance-leaved coreopsis (Coreopsis lanceolata). This species is native to central and southeastern United States, although it does just fine in our area. This member of the aster family thrives in poor soil as long as there is good drainage.
Yellow sweet clover (Melilotus officinalis) is probably found elsewhere in the Park, but so far this is the only group we have come across. It has yellow flowers and compound leaves that are typical of the bean family. A Eurasian species that seeds readily, it is considered invasive in some habitats.
We found a few other species along the path of the Reservoir. The photo below is of bladder campion (Silene vulgaris). Notice the balloon-like calyx. The calyx is what the collection of sepals is called, the outermost structures in a flower. There is a native campion (Silene stellata) that has a swollen calyx also, but can be distinguished because it has fringed petals. The species we found has only small notches in the petals.
There are 5 species of copperleaf listed in Gleason and Cronquist, we have found at least two of them. Today Daniel noticed a third growing along the Reservoir path. This new record for Central Park was first documented in the Northeast by Thomas Delendick in 1990 (http://goo.gl/tYQEXq). He found a few plants growing along the sidewalk in front of a brownstone in Park Slope, Brooklyn. It has since spread to all five boroughs and beyond. (http://goo.gl/JX0nx1). Acalypha australis. We will have to keep an eye out to see how common it is in the Park.
In my post about the 79th Street transverse road, I spoke about the far eastern smartweed, Persicaria extremiorientalis. There is a large, robust stand of it growing at the north end of the Reservoir.
Finally, I will leave you with a photo of a common plant we have already seen in these blog posts, common milkweed (Asclepias syriaca). Part of what is fun about this project is looking for new and interesting plants, but I have to say, I never get tired of the common species. This is a beauty of a native, important host plant for the Monarch butterfly caterpillar and that seed pod is just spectacular. Look closely and you will see a small lady-beetle, probably feeding on aphids which are feeding on the sap of the milkweed. Ordinary is not necessarily dull.
*Manual of Vacular Plants of Northeastern United States and Adjacent Canada, second edition by Henry A. Gleason and Arthur Cronquist, published by the New York Botanical Garden, 1991.