Helen FieldsScience Writer

Bet you didn’t know this museum existed: The National Bonsai and Penjing Museum. It’s right across the street from the National Herb Garden and a short walk from the National Boxwood Collection and the National Grove of State Trees. They’re all part of the National Arboretum, one of Washington’s real hidden gems. It’s on New York Avenue, a road that wants to be a highway, lined mostly by motels and unattractive semi-industrial-looking sites. But behind its fence is this lovely, green refuge you would never imagine.

The museum started in 1976, when a bunch of Japanese bonsai growers donated trees to the U.S. as part of the Bicentennial celebrations. This was one of the original gifts, and it’s the oldest tree in the collection:

This Japanese white pine has been “in training,” the label says, since 1625. 1625! It was passed down through generations of the Yamaki family, who had a bonsai nursery in Hiroshima. Their nursery was less than two miles from where the atomic bomb went off, but the Yamaki family and their trees avoided major injury. Here’s a nice article about the tree from the National Bonsai Federation.

Normally I think that tree is displayed with a less distracting background, but in winter they collect all the bonsai and penjing (the Chinese version of bonsai) in one pavilion and put a temporary roof on it. Since everything outdoors was covered with a hard, thin crust of ice yesterday, this decision seems to make a lot of sense. These trees are from temperate environments, so they need shorter days and cooler temperatures for part of the year, but that doesn’t mean they need East Coast-style ice storms. “Greetings, venerable pine! We hope you don’t mind if we hang 16 pounds of ice on your perfectly shaped branches!”

Those branches don’t perfectly shape themselves. Here’s a European Hornbeam having its twigs molded:

This plant is a bit younger–an upstart, really, compared to the Yamaki pine. It’s only been in training since 1972. The bonsai collection has been supplemented over the years by donations from bonsai enthusiasts, including a gorgeous Japanese white pine given by King Hassan the 2nd of Morocco. I don’t know if he was a bonsai grower, but he apparently owned at least one.

It’s cool to see all these plants in winter. It also made me want to go back to see them when they bloom and leaf out in the spring. Just think of the years, decades, and centuries of loving care that go into making and maintaining these perfect indoor representations of outdoor life.

Bonsai appeal to my sense of cuteness. You expect to see little fairies dancing on the moss under the trees. We’ll have to settle for this guy, though.

For all my Museum Tourist posts, click here.

Plants are amazing. I said this to a friend yesterday and he corrected me: “Everything is amazing.” Which is true. Kidneys? Amazing. Meteorites? Amazing. DNA? Amazing.

But, for now, let’s talk about plants. They’re amazing. They can communicate by releasing chemicals. Messages like, “Come eat the tasty caterpillars!”

For ScienceNOW last week, I wrote about a study on tobacco plants that, when they’re being chomped by caterpillars, send out a chemical message that calls the caterpillars’ predators. Amazing, huh? Read about it here.

photo: Matthey Film

Some scientists at the University of Georgia are working on what sounds like a kind of goofy project: making ornamental clovers. They swear they’re very pretty plants – lush green, with red and white markings. And they fix nitrogen, so they could help fertilize your garden, too. The Georgia team has actually bred three ornamental varieties, called Patchwork Quilt, Irish Mist, and Pistachio Ice Cream, which they’ve turned over to the university to commercialize. So keep an eye out for these to plant in your garden.

In the course of all this breeding, the team has been working on mapping genes for different traits – including the four-leaf trait. This turned out to be really tricky. So, there’s a gene for four leaves. But just because a plant has a gene doesn’t mean it’s always turned on. (You have a ton of genes for making digestive enzymes. The cells that line your small intestines turn these genes on, but you should be pretty grateful that the cells that line your eyeball don’t.) The four-leaf trait comes and goes depending on the season, for example. It’s also recessive. If you want to map it, you need a grad student who’s willing to spend a few years crawling around on her hands and knees counting leaves.

I wrote about that grad student, and the four-leaf gene, for the July 9 issue of Science magazine – but you have to have a subscription to read my story. (Or if you e-mail me and ask nicely, I’ll send it to you.)

Photo: came with the press release. I can’t find a credit for it.

Ecologists have struggled for years with the question of why tropical forests are so diverse. There are all kinds of hypotheses going around out there – I read papers on many of them in a class in the fall of 1996 and must admit, I’ve forgotten them. Except for one, because I just had to relearn it: Baby trees can’t grow too close to other trees of the same species, because if they do, their enemies – insect herbivores, viruses, whatever – will find them. So if I’m a tree of species X, I won’t do as well near another tree of species X, because special disease Y that only likes tree species X will find me and kill me. If all the species have the same problem, they all have to be spaced out and leave open space for other species to fill. Result: diversity.

Of course, this hypothesis is also proposed for trees in temperate forests, so I still don’t know why they’re less diverse.

But anyway. Today for ScienceNOW I wrote about a related hypothesis, about why some trees are common and some are rare: Maybe the common ones are able to get common because they’re not as susceptible to natural enemies. Maybe they’re more resistant to disease or herbivores or something, so they can survive the experience of being close to another tree of the same species.

For the paper I wrote about today, the researchers took advantage of a giant, long-term forest plot on Barro Colorado Island, a Smithsonian research site in Panama. In the early 1980s, a team laid out a 50-hectare plot and mapped every tree with a diameter of one centimeter or larger. The plot has almost 350 species of trees and shrubs.

In 2001, they took it a step further. A team of field assistants worked for 10 months to mark 20,000 one-meter-squared subplots. In each one, they measured every seedling that was 20 cm or taller and marked it with a bird band from a company that supplies poultry farms – chicken bands are made for mucky, organic environments. “The numbers really hold up in the tropics,” says ecologist Liza Comita, of the National Center for Ecological Analysis and Synthesis in Santa Barbara, California. Every year or so, the seedlings are censused again.

She used those data to look at seedling survival over five years, and found…well, I don’t want to give away the ending. Read my story here. Credit for the funny headline goes to editor Mitch Leslie.

Photo: Liza Comita

Yesterday for ScienceNOW I wrote about tobacco plants that open their flowers at a different time of day if they’re getting eaten by caterpillars. (My story.)

It’s kind of ingenious, if these scientists are right about it. Hawkmoths are good for the tobacco plants, because they pollinate them. Plants want pollination. But female hawkmoths also lay their eggs on the tobacco leaves. Eggs hatch into caterpillars that eat everything in sight.

So if there are caterpillars around, this study shows, these plants shift their flowering from night – when moths are out – to morning, when hummingbirds are awake.

Plants have a ton of ways of dealing with predators. They can produce toxins to hurt the predators. They can stop making new leaves, send new sugars to their roots, and wait until the predators go away. My favorite: They can send out “heelllp meee” chemical signals to attract their predators’ predators, like a parasitic wasp that lays its own eggs in the caterpillar.

One of the guys I talked to for this story told me (when I interviewed him for another story) that he used to be able to tell what species of caterpillar was eating a plant in his lab by the smell of the chemicals the plant was giving off. They’re that specific.

Plants are awesome.

photo: Danny Kessler

About a month ago, I wrote about a visit to Harvard’s Museum of Natural History. Friend, fellow science writer, and Bostonian Lila Guterman asked me why I hadn’t written about the glass flowers. Because they’re so awesome they deserve their own post, that’s why.

In the late 19th century, father-and-son team Leopold and Rudolph Blaschka were making glass models of invertebrate sea creatures. There wasn’t a good way to preserve jellyfish and such, so they made lifelike, detailed models out of glass. The head of Harvard’s Botanical Museum found out about them and hired them to make glass models of plants.

So I’m at the museum. I know the glass flowers are famous. I walk into the glass flower room. I look at the first display case:

And I’m like, well, ok, that’s a perfectly nice specimen of a grass, so where are the glass flowers?

It took me a while to catch on that, no, really, everything was glass. I expected it to look like…glass. Shiny. A little translucent. But that’s not what the Blaschkas were doing; they were making something that looked exactly like the real thing, for study purposes.

See? Just looks like a cactus. A real pretty one, with a flower. The card in front of it tells you it’s an Echinocereus engelmannii modeled on a specimen collected in Tempe, Arizona in June.

An advantage of working in glass (as opposed to working in, uh, plants) is that you can magnify the specimens. A lot of the plants were shown with blown-up sexual organs:

Other than the magnifications, they just look like plants in cases. If you don’t know they’re made of glass, it’s not a very impressive room. But if you do know? Wow!

For all my Museum Tourist posts, click here.

photos: me. allllll me.

Part of the deal with this fellowship is that I’m also supposed to do my regular work. So, here it is: a news story about rice genetics. I know, it sounds boring, but it’s totally not! Modifying rice is a big deal – in 2005, 20 percent of the world’s calories came from rice, and production is going to have to increase to keep up with population growth. So this piece is about one cool new study on finding a gene that helps rice survive floods.

An interesting point about this work is how old-school it is. They’re looking for genes, but not using super-newfangled proteomics or whatever techniques – instead, they look for them by doing lots of mating plants together and looking for crossovers, like I learned about in intro biology in approximately 1994. Ok, yeah, computers do all the calculations now. But if they were teaching it in intro biology in 1994, believe me, it was basic.

Then when they find the gene, they don’t put it into another plant with viruses or fancy-schmancy genetic transformations – they do it with breeding. Sure, they use molecular techniques to make sure they’re getting the right genes in the offspring (this speeds things wayyyy up). But basically it’s good, old-fashioned plant sex.

Neat, huh? Made me want to learn more about the world of rice research.