Evergreen Ferns

Now that the snow has melted and one can venture outside again, a feature of the late fall/early spring forest landscape you might notice is a surprising amount of green. This is due in part to evergreen ferns. These are a select set of species that drop their fronds to the ground in late fall, but keep them attached to the base of the plant, where they remain green through the winter months. There's actually a nifty mechanism by which this occurs: there is a joint right at the base of the frond that weakens at the appropriate time, so that the frond falls where it's been standing.

There are various hypotheses in the fern community about why these species do this. The consensus seems to be that having green, living fronds may allow them to jump-start photosynthesis in the spring when the snow melts and sunlight becomes available. Based on the ferns in the forest at my parents' house (where the above photos were taken), that seems like a reasonable theory. There are several species in the North American fern flora that do this, including Polystichum acrostichoides (middle photo, above; its common name, Christmas fern, reflects the fact that is a dark green color through late December) and Dryopteris intermedia (lower photo, above).

I should mention that these ferns aren't truly evergreen, in the sense that conifers are. Conifers hold their leaves through multiple growing seasons (although they do replace them eventually, usually once every 3-5 years). These ferns keep their fronds only until the next spring; when the fiddleheads start to emerge they will begin to senesce and disappear into the leaf litter.

Interrupted Fern

The snow is starting to melt in Wisconsin, so I'm looking forward to the arrival of spring and a return to regular blog posting. I saw this posted on a friend's Facebook profile the other day and wanted to share it: an amusing comic about Interrupted Fern (a.k.a. Osmunda claytoniana). Of course, it really gets its name from the fertile pinnae that "interrupt" the sterile green pinnae along the rachis (see below). But the comic (drawn by Rosemary Mosco of birdandmoon) is a good interpretation, too. 

Darwin and Botany

2009 is a big year for evolutionary biology. In a few weeks, on February 12, we will celebrate Charles Darwin's 200th birthday, and later this year marks the 150th anniversary of publication of the Origin of Species (such a smart man, I'm sure he planned it that way!). In honor of this fascinating scientist and person, I thought I would provide the best links for reading Darwin online, and mention the intersection of botany with his thinking and works.

First off, let me comment that it's not going too far to say I love Darwin; he is a fascinating person, both as a scientist and a man. His writings are an incredible treat to read, accessible and full of tremendous insight into the natural world. The first book of his that I read was the Voyage of the Beagle, and if you haven't read it, I recommend you race out immediately and buy a copy. It is an easy, fantastic, exciting, thought-provoking read. If you aren't inclined to buy, you'll enjoy the first of these links:

• The Complete Works of Charles Darwin online  This treasure-trove is exactly what it claims to be: all of Darwin's writings. All of them. That means all of his major books, including the Origin, plus his numerous papers, many of which are botanical, and page-by-page images of his many notebooks and diaries.
• The Darwin Correspondence Project   The DCP's goal is to publish all of the letters Darwin sent and received and that are extant (i.e. weren't lost or thrown out). The Correspondence is voluminous; Darwin had close to 2000 correspondents and wrote up to 500 letters a year in the years following 1859. This site has most of the letters that have been transcribed, as well as letter sets on various subjects, and guides to reading the letters of different people. It is fascinating to read his correspondence with critics and with his supporters as he fleshed out his theories.

I cannot say enough about the delight you will get from reading Darwin. He was a joyful observer of the natural world, and his enthusiasm is clear in his writings. Also clear are his modesty and desire to be understood by his reader. 

I admit that I (like most scientists) haven't read many of Darwin's less-famous papers and books, but a good many of them are on botanical subjects. Darwin suffered from illness and infirmity for most of his later life, and he took refuge in his experiments and wanderings at Down House, which he vastly preferred to the scientific fray in London. He relied on correspondence with his botanical friends for a huge amount of information in the Origin, particularly about biogeography and the immutability of species, and in his later years he increasingly turned to botanical experimentation and direct observation himself. He published books on the following botanical subjects: orchid fertilization, climbing plants, insectivorous plants, cross and self fertilization, flower forms, and plant movement, as well as dozens of papers on everything from variegated leaves to whether sea water kills seeds. All of these are available at the Complete Works of Darwin website listed above, and it is great fun to explore his writings and see the world through his eyes!

Top 100 Botany Blogs

Happy February! Online college blog has assembled a list of what they consider to be the top 100 botany and plant-related blogs: Top 100 Botany Blogs. I'm very pleased and honored that No Seeds was included! We're down at #91, in the Plant Specific section. Go check out some of the others, all are wonderful and fascinating!

Dryopteris spores

Hello! I apologize for the two-month hiatus, it was unintentional. Classes and research slowly hijacked my every waking moment this semester, and as the cold and snow settled in here in Wisconsin, there was less and less to talk about in terms of living plants. However, I did get to work on a really cool project for a plant anatomy course I took this fall, which I wanted to share. Along with one of my labmates and another grad student in our department, I undertook a study of the spores of Dryopteris (my research group), to satisfy the class's project requirement. We got to learn how to use the scanning electron microscope that lives in the botany building, and got some beautiful results. Above is a scattering of spores from Dryopteris marginalis, and below is a figure from the paper we wrote:

A = D. arguta, B = D. carthusiana, C = D. celsa, D = D. cristata, E = D. expansa, F = D. filix-mas, G = D. fragrans, H = D. goldiana, I = D. intermedia, and J = D. marginalis. The scale bar is 20 micrometers... really small! It was a fun project, and the results may prove useful to me down the road in my research. I'll try to post more often over the winter break, if I can find anything living to photograph! Happy Holidays!

Botany Photo of the Day

The UBC Botanical Garden, which I had the great pleasure of visiting while in Vancouver this summer, posts a Botany Photo of the Day, every day. If you do the RSS thing (to which I'm addicted), here's an xml link. Go have a look at Elliottia pyroliflorus.

Berry Go Round #9

The latest edition of Berry Go Round, an awesome botanical blog carnival, is up at gravity's rainbow, and I'm very pleased to say that my post on Blechnum made the cut! Go check out all the cool blogging people are doing about botany!