Thursday, December 3, 2009
Tuesday, November 24, 2009
Take a moment today to wish a happy 150th birthday to the Origin of Species, published on November 24, 1859. This truly seminal work should be read by everyone, scientists and laypeople alike. Darwin was an eloquent and passionate writer, and there are many lovely passages in the book. My favorite has always been the very last paragraph:
"There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."
I think it's difficult not to find these words moving if you're anyone who gazes at stars or watches plants germinate or waits with bated breath for the latest news from the LHC. We've learned so much about the world during our species' short presence on this planet, thanks to the efforts of intrepid naturalists and researchers like Darwin, who live and breath for the pursuit of knowledge. The power of science to teach, to improve our lives, and to increase our understanding and appreciation of our fragile world is awe-inspiring. Truly, there is grandeur in this view of life.
Thursday, November 12, 2009
Ferns will have their day on the radio next Thursday, November 19. If you live in Madison, tune in to WORT 89.9FM for Perpetual Notion Machine from 7-7:30pm, or you can listen live online at WORT's site, or you can download the show as a podcast afterwards. Yours truly will be the guest, talking about ferns, science-blogging, and my favorite passage in the Origin of Species (whose 150th birthday is coming up soon...).
I just found this blog about ferns at La Selva Biological Station in Costa Rica. La Selva is one of the stations operated by the Organization for Tropical Studies, which ran a tropical fern course I took several years ago, part of which was taught at La Selva. It's a really neat place in the lowland tropical rainforest of northern Costa Rica, with lots of ferns. This video-blog documents research that's being done on the La Selva ferns, some of it by students, and it's really great!
Here's their most recent post, on Lomariopsidaceae. Go visit the blog to learn more!
Thursday, November 5, 2009
Olbrich Botanical Gardens. And one of the nicest things about the Garden is that, in addition to having many ferns on the grounds, they have this beautiful cement statue of fiddleheads prominently displayed! I was stunned the first time I saw it, and now it's one of my favorite things to visit in town. I don't know anything about who designed or made it, because I haven't been able to locate a plaque or sign. It's now become a mission to find out the name of the artist who appreciates ferns this much.
Update, March 2010: A former student of mine discovered the identity of the sculptor: her name is Sylvia U. Beckman. Thanks Lois!
Thursday, October 8, 2009
If I had to guess, I would say that the most common fern on Hawaii in terms of sheer biomass is Nephrolepis. There are several species in this genus on the Big island, and it is everywhere! Along roadsides, on lava, almost everywhere you look. It is truly ubiquitous. It's a lovely fern, with bright green fronds and very erect stature. The popular houseplant Boston Fern is also a member of this genus, and you can probably see the resemblance:
Here are some Nephrolepis growing in a tree mold in a lava field at Kilauea:
Another fern we found out on the lava in Hawaii was Pityrogramma austroamericana, a little bright green thing that has an interesting feature common in ferns that live in dry, challenging environments: farina. Farina is a powdery layer on the lower (abaxial) surface of the frond, which is usually white or yellow, and is thought to reflect light and therefore heat, cooling the frond. Many ferns in the deserts of the southwestern U.S. have farina, and it's a defining characteristic of several groups of ferns. This is one of the only farinose ferns in Hawaii.
Wednesday, September 30, 2009
The Preservation of Favored Traces. It traces all of the edits Darwin made to the Origin as it went through six editions during his lifetime. This project traces them, color-coding by edition, and if you mouse over it you can read the color-coded edits. It's sort of mesmerizing, and a great distraction if you're a bit of a Darwin geek, or even if you're not...
Sunday, September 6, 2009
One more post about lava; specifically, lava tubes. We visited the famous Thurston Lava Tube in Volcano National park, a giant tunnel left in the surrounding lava by a flowing lava wave that passed through, hollowing out as it went. The entrance to the tube is in a depression that makes a nice little micro-climate for many ferns, which are draped luxuriously around the entrance. Adiantum is the most common fern in these photos:
Once you get inside the lava tube (next picture), you're not done with the ferns... around every one of the light fixtures installed to illuminate the tunnel, spores have germinated and ferns are growing. A testament if ever there was one to ferns' ability to photosynthesize in low light conditions!
Saturday, September 5, 2009
The most conspicuous feature of Hawaii, for someone who has never been there before, is undeniably the lava. The entire terrestrial surface of the islands is made of this stuff, a dark, craggy, ominous-looking substrate which looks suspiciously like it should still be hot to the touch from its eruptive moment of creation. In fact, for much of the lava on the south-east side of the Big Island, in the active volcanic zone, this is almost literally true. Many of these flows were formed within the last century, some of them in the last 30-40 years, and lava is still actively erupting today.
The next thing a newcomer to Hawaii might notice, after oggling the lava, is the green stuff on the lava. That would be the plants. And in most cases, the first colonists and only plants intrepid to live out on this stuff, are ferns. Ferns are excellent dispersers because of their lightweight, durable spores, so they are often the first plants to reach newly-available substrates, like lava. Here's a small sampling to give you a feel for the desolation of the lava, and hopefully, an appreciation for the indomitable nature of the ferns that live on it!
The ferns in the right photo above and at the top of this post are species of Sadleria, and the small ferns in the next photo down are Polypodium pellucidum.
Tuesday, September 1, 2009
Hawaii has eight endemic species of Elaphoglossum, which are simple, entire-leaved ferns that are often ephiphytic (growing on trees) but can be terrestrial as well. We found two species on our trip, both in a kipuka, an area of lava that is older than the lava around it, and so forms a sort of vegetated island in the middle of an otherwise desolate, young lava flow. Kipuka will often be grassy or forested, and the one we visited was the latter.
One of the species we found was Elaphoglossum paleaceum, which is easy to identify because of its nodding habit and profuse golden scales; it is pictured above and in the next two photos. The remaining photos are of the other species in the kipuka, which had an erect growth form and was not as densely scaly. Its identification was a little less straightforward... I will stick with calling Elaphoglossum sp., at least for now.
Saturday, August 15, 2009
We found two species of Cyrtomium in the Mauna Loa Bird Park near Volcano National Park. I'm very partial to this genus because it's commonly found in greenhouses and botanical garden conservatories where they want to create a very tropical-feeling environment, but it's rarely labelled. It also doesn't look much like a fern unless you turn it over and notice the sori.
This is Cyrtomium caryotideum:
And Cyrtomium falcatum:
Another important genus of ferns in Hawaii is Asplenium. This group is found throughout the tropics, and there are several species in the Hawaiian islands. Asplenium species have linear sori, which can be found in other genera as well, but they can help you figure out if something could be an Asplenium: