An apple for the teacher

With her fellow educators in mind, Katherine tells a story of virtual botany in the dining hall and letting students be teachers.

When we botanists in the kitchen are quiet for a little while, it usually means we are focusing all of our attention on our day jobs.  Like a garden, the academic calendar has a rhythm that cannot be ignored, and from April through June, I pour most of my time and creative energy into my small seminar class, where we dig into the evolutionary and ecological connections between humans and plants across many time scales and topics. It’s a fun class and the debate is usually lively, but because the journal articles we discuss are often dense and technical, I sometimes worry that we are squelching some opportunities for joy.

To keep things sunny and bright this year, I played around with one of my usual assignments and gave the students a real creative opportunity: make an engaging video about an edible plant species that could be found in their dining halls, illustrating structure, origin and evolution, cultural history, nutrition, etc.  The assignment was directly aligned with one of my goals for the course: to combat “plant blindness” by drawing attention to plants in our daily lives, including plants on our plates.  The videos that grew out of this exercise can now be shared publicly, to the benefit of interested eaters everywhere, not just those in my class.  Select examples are linked below.

Carrots, by Marika Sitz
Asparagus, by Michael Penuelas (Michael does understand the difference between phenology and phylogeny.  He just misspoke.)
Cantaloupe, by Tim Asdoorian
Cuties, by Sophia Colombari Figueroa

Lessons learned
If you are a teacher and are tempted to try this assignment in your own class, please do keep reading. This was a fun but time-consuming and somewhat intimidating exercise that happened to work very well in my class because it absolutely supported my specific learning goals. It may not be as natural a fit for others. Fortunately for me, the students were enthusiastic, and they made some wonderful videos. I was impressed with their creativity, sense of fun, willingness to try new technology, and ability to pull something together under a tight deadline. They nurtured their inner teacher as they became briefly obsessed with melons and baby carrots. I did have to reallocate some class time to talking about this assignment and its technical aspects; however, it was easy to justify taking time to build fundamental science communication skills.

The three most important lessons I learned from making this assignment were

1. there are essentially no technical obstacles to making videos like these,

2. peer review of proposals, story boards, and rough drafts is essential to a good final product,

3. and the process allows a conversation about the critical importance of proper citation and fair use of music and images.

1. Technical aspects are secondary 
To my surprise, most students did not use presentation software to create their videos, even though Powerpoint and Keynote slide decks can be exported easily as video files. One person used an online presentation platform (Prezi) to build her video about “cuties,” but almost everyone else used live video or a series of stills. My own demonstration video, about apples, was built from Keynote, and I relied heavily on the transition options built into that program. The class, however, preferred the old-school look of stop-action and a shaky camera. Many of them simply used their phones or equipment borrowed from the university library to capture the images. Editing was done with iMovie or other widely available software. My colleague Carlos Seligo, an Academic Technology Specialist with a great eye for editing, attended my class one day to work with students individually on their drafts. Of course all of the students were happy to share in class the tricks they had discovered on their own.

2. Peer feedback, early and often
The challenge I gave the class was to choose an ordinary fruit or vegetable and make it interesting – to other people. Smart people can become fascinated with just about anything if they spend enough time with it, but these videos needed to engage naive viewers immediately. As students mucked about waist-high in their research, peer feedback really helped to keep everyone’s head above ground and focused on a public audience.

Early in the quarter, I asked each student to pitch a proposal to two others. Later, they paired off and narrated their story boards – a sequence of sketches outlining the video. Finally, a week before the videos were due, they brought drafts in for editing and technical help. At the first two stages, I provided evaluation sheets with a few simple but specific questions to guide their critiques. The sequence of deadlines, with peer accountability, kept most people on pace to finish without too much pain or too little sleep. It also built enthusiasm and a sense of community around individual projects.

3. Credit where it is due
Everyone who teaches is responsible for inducting students into a broader community of scholars with a set of norms governing the proper use of others’ work. If we make factual claims that are not simply obvious, we should back up those claims, either with our own data or by citing a reliable source that can be verified by the reader. If we use images or music or video, we should use them with permission and cite them properly. An important requirement of the video assignment was proper citation of both scientific and creative content, and not all of the videos fully met the standards. Only those that (mostly) did are linked here.

Fortunately, it is not hard to find images and music in the public domain or released under a Creative Commons license. It is also easy and fun to make your own images and animations. It is much harder to root out all of the places you have erred and to fix them; I’m still on the lookout for violations in my own class lectures and blog posts. The entertaining and unflinching Colin Purrington has written extensively about the many ways we inadvertently teach our students to plagiarize and why we should stop now. I recommend his work very highly to all educators:

High yield
Video turns out to be an excellent medium for botany lessons based on food. Edible plants are beautiful on their own, and their stories can be told with colorful maps and cultural images.

Making a video takes time, but so does (should) writing a paper. In that respect, I did not impose superfluous work on the students. If anything, their efforts yielded more benefits than would a hastily written paper. Because the content – basic structure, use, and history – was straightforward, students sifted through a lot of information to decide what was credible and what would be most interesting. Several drove the narrative with an engaging personal story. Tim’s history of cantaloupe, linked above, nearly brought me to tears.

The video format itself focused attention on connections among parts of the story, integrating disparate bits of information to make them more memorable. It’s true that the videos, unlike a paper, did not really accommodate nuance, but I was willing to give up some depth in this project because other class assignments played that role.

Because the videos were made for a public audience – and we are working to get them played in the dining halls – everyone accepted the responsibility of being a teacher. And they learned that teaching, like learning, can be really fun.

More on “plant blindness”: James H. Wandersee and Elisabeth E. Schussler (2001) Plant Science Bulletin  47:1

A biologist eating for two

This is a bit tangential to our usual fare, but I think it’s fun, and you may as well. A friend of mine, Cara Bertron, edits the creative and delightful quarterly compendium Pocket Guide. I submitted this image, entitled “A biologist eating for two,” for the current issue, which is themed “secret recipes.” It’s a cladogram of the phylogenetic relationships among all the (multicellular) organisms I (knowingly) ate when I was pregnant with my now two-year-old daughter. Continue reading

Going bananas

What can make me feel less guilty about buying bananas? Science.


Trying to get the banana back in the peel

I am genuinely curious about the size of the fraction of carbon in my two-year-old that is derived from bananas. When we have bananas in the house, which is most of the time, she eats at least part of one every day. She loves them peeled, in smoothies, dried, in banana bread, or in these banana-rich cookies, which sound like they shouldn’t be good but are totally amazing. Bananas are inexpensive and delicious, and making nutritious food with them gives me a sense of parental accomplishment. Nonetheless, always I feel a niggling sense of guilt whenever I plunk a bunch of bananas into the shopping cart. Prosaic though it may be, most of this is contrition inspired by the “local food” movement. I know that very little is benign about the process responsible for bringing these highly perishable tropical fruits to my table for less than a dollar a pound. The remainder of my remorse is conviction that bananas should not be taken for granted. Not only is banana history and biology interesting, but the banana variety in our grocery stores, the Cavendish, is in danger of commercial extinction. There isn’t an easy solution to the problem or an obvious candidate for a replacement variety. The history of the Cavendish’s rise, and the biology behind its current peril, makes for a good story. Continue reading

Our Easter Bunny is a Botanist

Plant-dyed Easter eggs inspire a glimpse at the diversity of plant pigments.

(scene from Pride and Prejudice of dying ribbons with beets:

(scene from Pride and Prejudice of dying ribbons with beets)

Pigments serve a variety of roles in plants. Many pigments have physiological roles within plants and protect plant tissues from sunburn and pathogens and herbivores (see review by Koes et al. 2005). Most noticeably, however, their brilliant colors attract animal pollinators to flowers and seed dispersers to fruit. Humans are also interested in plant pigments, in part because they color and sometimes flavor our food, are potentially medicinally active, and have been used as natural dyes and paints for millennia.

red cabbage

red cabbage

Last weekend I made some natural Easter egg dyes from turmeric and beets (I followed these instructions). We also considered making dyes from red and yellow onion skins or red cabbage, but we kept it simple. This handful of plants used to make cheap, easy, homemade dyes can give us some insight (“some” in this case being “a very small amount”) into of the chemical and evolutionary diversity of plant pigments. Continue reading

Origin stories: spices from the lowest branches of the tree

Why do so many rich tropical spices come from a few basal branches of the plant evolutionary tree?  Katherine looks to their ancestral roots and finds a cake recipe for the mesozoic diet.

I think it was the Basal Angiosperm Cake that established our friendship a decade ago.  Jeanne was the only student in my plant taxonomy class to appreciate the phylogeny-based cake I had made to mark the birthday of my co-teacher and colleague, Will Cornwell.  Although I am genuinely fond of Will, I confess to using his birthday as an excuse to play around with ingredients derived from the lowermost branches of the flowering plant evolutionary tree. The recipe wasn’t even pure, since I abandoned the phylogenetically apt avocado for a crowd-pleasing evolutionary new-comer, chocolate.  It also included flour and sugar, both monocots.  As flawed as it was, the cake episode showed that Jeanne and I share some unusual intellectual character states – synapomorphies of the brain – and it launched our botanical collaborations.

Branches at the base of the angiosperm tree
The basal angiosperms (broadly construed) are the groups that diverged from the rest of the flowering plants (angiosperms) relatively early in their evolution.  They give us the highly aromatic spices that inspired my cake – star anise, black pepper, bay leaf, cinnamon, and nutmeg.  They also include water lilies and some familiar tree species – magnolias, tulip tree (Liriodendron), bay laurels, avocado, pawpaw (Asimina), and sassafras. Continue reading

Let’s get it started with some black-eyed peas (and rice)

You don’t have to be superstitious to believe in the power of hoppin’ john on New Year’s Day.  Katherine’s recipe is below, but first, she takes this good excuse to talk about the structure of beans, the magical fruit (really seeds).

The magic of beans
Beans are extremely satisfying seeds.  They are large and germinate easily.  They can be harvested young and eaten soft – like limas, favas, and green peas – or in their fresh pods, like green beans and sugar snap peas.  They are most beautiful and useful when allowed to mature and dry naturally.  They are creamy white, chestnut, blue-black, or pink; mottled, speckled, cow-spotted, or black-eyed; fat and reniform, or shaped like a lens or a ram’s head.  They can weigh down pie crusts or fill bean bags.  Food co-ops everywhere are built on the cornerstones of bulk bins full of colorful dried beans.  Running your hands through a bowl of cool dried beans is an inexplicably simple joy. Continue reading

Hollies, Yerba maté, and the botany of caffeine

Yerba maté, the popular herbal tea from South America, is a species of holly. It’s also caffeinated, a characteristic shared by only a small number of other plants.


English holly. Photo by K. Bills

Along with conifer trees and mistletoe, hollies are a botanical hallmark of the winter holiday season in Europe and the United States. Most hollies are dense evergreen shrubs or small trees and produce beautiful red fruits that stay on the plant through the cold winter months. Sprays of the dark green foliage grace festive decorations, and wild and cultivated hollies punctuate spare winter landscapes. Especially popular in winter, too, are warm beverages. One of the most popular, at least in South America but increasingly elsewhere, is yerba maté. It is a seasonally appropriate choice because the maté plant is a holly. Unlike the decorative hollies, usually American (Ilex opaca) or English (Ilex aquifolium) holly, maté (Ilex paraguariensis) is caffeinated. This puts it in rare company, not only among hollies, but among all plants. Continue reading

Cranberries, blueberries, and huckleberries, oh my! And lingonberries, billberries…

Flavorful and juicy thought it may be, Thanksgiving turkey, for me, is merely the vehicle for the real star of the meal: cranberry sauce. And cranberry is in the same genus as blueberries, lingonberries, huckleberries, and billberries. And they all make their own pectin. Let us give thanks this holiday season for Vaccinium.

Cranberry sauce is my favorite staple item at our big holiday dinners. Long-prized by indigenous North Americans, cranberries would have been in the diet of those Native Americans participating in the first Thanksgiving if not part of the meal itself. When the fresh cranberries hit the stores in late fall, we stock up. Cranberries, however, are not the only member of their genus that is perennially in our freezers or in our annual diet: blueberries, many huckleberries, lingonberries, and billberries are all in the large genus Vaccinium (family Ericaceae, order Ericales). Continue reading

The irrational nature of pie

What is a nut, and why is the answer so convoluted? For Thanksgiving, Katherine explores pecans and the very best vegetarian turkey substitute ever: pecan pie.

Thanksgiving is all about tradition, and wherever there is tradition, there are entrenched ideas about the right way to do things. Strong opinions can breed discord, judgmental grumbling, or silent rants about how people with so little sense cannot possibly be blood kin or their freely chosen companions. So much for the theory of mind we all developed as toddlers. And so it goes with my feelings about pecan pie.

Pecan pie is properly made according to the recipe on the Karo syrup bottle, preferably by my own father. The recipe does not include bourbon. To be clear, I love bourbon. Bourbon is our only indigenous whiskey. It is made of corn and aged in American oak. I love bourbon, and I respect it enough to drink it neat, from a glass, alongside my pie.

We can all agree that pecan pie should not be rolled in molasses, breaded with crushed pork rinds, and deep fried. Some reasonable people, however, do add chocolate. It might taste just fine that way – even delicious – but it disqualifies the resulting pie from the category under discussion. Sneaking it in under another name doesn’t work either. When the good bourbon-loving people of Kentucky add chocolate to a pecan pie and call it Derby pie, not only are they infringing on a trademark, they are using the wrong kind of nut. Derby-Pie ® is made with walnuts. There is therefore still no excuse for adulterating good pecan pie with chocolate.

What is a pecan?
A pecan half is a rich fat-filled embryonic leaf (a cotyledon) from a pecan tree seed. The flat side of a pecan half bears a pale shield-shaped scar where it was joined to the other cotyledon and where a tiny knobby embryonic root sits waiting for the chance to grow out and start drawing up water. Each pecan half is wrinkled like a brain hemisphere, crammed into its shell. In the natural world, when conditions are right for germination, a pecan seed imbibes water and its cotyledons swell enough to crack open the shell. The cotyledons provide an extremely calorie-dense sack lunch for the seedling to draw upon until it develops leaves and starts photosynthesizing food on its own. Continue reading

Nasturtiums and the birds and the bees

Hummingbirds and ancient bees are responsible for the color and shape of nasturtium blossoms and have a unique view of them, explains Jeanne over salad. 

Nasturtium flowers cut into tomato salad with parsley

Nasturtium flowers cut into tomato salad with parsley

Fall frost hasn’t yet claimed our nasturtiums (Tropaeolum majus; Tropaeolaceae family). The large, colorful blooms amidst the round leaves are still spilling over planting boxes.  All parts of the plant are edible and boast spicy mustard oil glucosinolates, betraying the plant’s membership in the order Brassicales, along with the cruciferous vegetables and mustard in the Brassicaceae family, capers (Capparaceae), and papaya (Caricaceae; try the seeds, as suggested here). I’ve heard that the immature flower buds and immature seed pods can be pickled like capers, but I haven’t tried it yet. Mostly I use the flowers, throwing a few in a salad or chopping them coarsely with other herbs and stirring them into strained yogurt or butter to put on top of roasted vegetables or lentils. In addition to the mustardy kick, the sweet flower nectar adds to these dishes. Continue reading