Sunday, August 15, 2010

Robert Treman State Park, NY

The last field trip I took while in Ithaca was to Robert Treman State Park. This is a beautiful place with many miles of trails connecting the Upper entrance, descending past waterfalls and through gorges, to the lower entrance several miles away. We started at the upper entrance and hiked down past Lucifer Falls, in search of a grove of Dryopteris goldiana that was known to occur near the base of this waterfall. We found it growing happily in a lush carpet of Vinca:

Farther along, we also came across some Asplenium trichomanes growing on a little shelf in the rock wall, and near the end of the trail, back at the upper parking lot, we spotted a patch of Cryptogramma stelleri, which I hadn't seen in the wild before. Two photos of each are below. All in all, a great trip to upstate New York!

Wednesday, August 11, 2010

East Malloryville Preserve, Ithaca, NY

After visiting Thurber Preserve I was eager to see how the other populations of Dryopteris around Ithaca were doing, so I went next to one of my very favorite nature reserves, the von Engeln or Malloryville preserve. This is a beautiful place with a very nice, easy to hike trail system. The trails start on top of glacial eskers and wind downhill into swamp and bog, which are traversed by boardwalks. There are many, many ferns here and I was happy to find several Dryopteris that I had been hoping to discover here, but hadn't seen previously, including D. goldiana:

Tuesday, August 10, 2010

Thurber Preserve, Dryden, NY

After the Botany conference I travelled to upstate New York, where I used to live, and where there is an abundance of Dryopteris species (if only I'd known while I still lived there...). I visited several preserves and state parks, some of which I hope to use as field sites for additional physiology studies to be conducted next summer. One of my favorite places is Thurber Preserve, since it was there that I saw D. clintoniana for the first time. I wanted to go back to check on the population and make sure it would be healthy enough to withstand a few measurements next summer, and I was delighted to find that the ferns are doing great! The population was larger than I remembered, and spans the edge of the swamp from forest to thicket, mostly in the shady areas. Wherever direct sunlight hit, that seemed to be the boundary beyond which D. clintoniana would not trespass.

This species is a polyploid, and the only hexaploid known in the North American Dryopteris complex (it has 3 duplicate genomes). Its putative parents are D. goldiana and D. cristata, the latter of which is a tetraploid (two duplicated genomes... so D. clintoniana has 2 from D. cristata plus 1 from D. goldiana and you have 3). This species most closely resembles its D. cristata parent, except that it is gigantic in comparison. It gets the size boost from D. goldiana. Notice in particular the horizontal arrangement of the pinnae in the photo below... the clear hallmark of D. cristata.

Monday, August 2, 2010

Dryopteris boottii

This summer the Botanical Society of America's annual conference was held in Providence, Rhode Island. As always, on the Saturday before the conference begins there are a number of field trips offered, and the American Fern Society usually co-hosts one. On this year's trip we went to several locations in Rhode Island and Massachusetts, and saw many of the common local ferns. One particular treat was seeing a Dryopteris hybrid I haven't seen before (which is surprising, since it's one of the more common ones). Dryopteris x boottii is a sterile hybrid between D. intermedia and D. cristata, the intermediate and crested woodferns.

There are clearly elements of both parents' morphology in this hybrid. The overall shape of the mature fronds resembles D. intermedia (first photo below), and the younger ones look like D. cristata (second photo below). The pinnae also have the unmistakable D. cristata-twist - they look like panes in a Venetian blind, each held horizontal relative to the rachis (see photo above). The plants are way too big to be just crested woodfern though, and there are occasional glands along the rachis and pinna blades that also identify the D. intermedia parent.