The United Nations declared 2016 the International Year of Pulses. What’s a pulse? It’s the dry mature seed of a large number of species in the legume family (Fabaceae): various beans, peas, soybean, chickpeas, lentils, peanuts and other groundnuts. 2016 is days from ending, so it’s high time I get up the Fabaceae diversity post I’ve been meaning to write all year long. This rounds out our year of legume coverage, which included Katherine’s posts on bean anatomy, peanuts, and green beans.
Christmas Lima beans (Phaseolus lunatus), soaking before cooking
One out of every 15 flowering plant (angiosperm) species is a legume, a member of the large plant family Fabaceae (Christenhusz and Byng 2016, LPWG 2013). Boasting around 19,500 species in 750-ish genera (LPWG 2013), the Fabaceae is the third-largest plant family in the world, trailing behind only the orchid (Orchidaceae: 27,800 species) and aster (Asteraceae: 25,040 species) families (Stevens 2016). By my count, people only use about 1% of legume species for food (my list of edible legume species is found here), but that small fraction of species is mighty. People eat and grow legumes because they are nutritional superstars, can be found in almost all terrestrial ecosystems around the world, and uniquely contribute to soil fertility in both wild and agricultural ecosystems. Continue reading
This is our first of two contributions to Advent Botany 2015.
Sugar plums dance, sugar cookies disappear from Santa’s plate, and candied fruit cake gets passed around and around. Crystals of sugar twinkle in the Christmas lights, like scintillas of sunshine on the darkest day of the year. Katherine and Jeanne explore the many plant sources of sugar.
Even at a chemical level, there is something magical and awe-inspiring about sugar. Plants – those silent, gentle creatures – have the power to harness air and water and the fleeting light energy of a giant fireball 93 million miles away to forge sugar, among the most versatile compounds on earth, and a fuel used by essentially all living organisms.
Sugar naturally occurs in various chemical forms, all arising from fundamental 3-carbon components made inside the cells of green photosynthetic tissue. In plant cells, these components are exported from the chloroplasts into the cytoplasm, where they are exposed to a series of enzymes that remodel them into versions of glucose and fructose (both 6-carbon monosaccharides). One molecule of glucose and one of fructose are then joined to form sucrose (a 12-carbon disaccharide). See figure 1.
Sucrose is what we generally use as table sugar, and it is the form of sugar that a plant loads into its veins and transports throughout its body to be stored or used by growing tissues. When the sucrose reaches other organs, it may be broken back down into glucose and fructose, converted to other sugars, or combined into larger storage or structural molecules, depending on its use in that particular plant part and species. Since we extract sugar from various parts and species, the kind of sugar we harvest from a plant, and how much processing is required, obviously reflects the plant’s own use of the sugar. Continue reading
Posted in Flavor, The basics, Uncategorized
Tagged diversity, Jeanne L. D. Osnas, Katherine Preston, phylogeny, plant, species, sugar, sugar beet, sugarcane, sweet
We’ve got several posts in the pipeline – and this year we are contributing to Advent Botany – but meanwhile, we bring you posts from the past to nerd-up your kitchen as you cook. Don’t forget, nothing deflects from an awkward personal revelation or a heated political conversation like a well-placed observation about plant morphology.
We wish you a happy, healthy Thanksgiving!
If it smells like onion or garlic, it’s in the genus Allium, and it smells that way because of an ancient arms race. Those alliaceous aromas have a lot of sulfur in them, like their counterparts in the crucifers. You can combine them into a Brimstone Tart, if you can get past the tears.
The genus Allium is one of the largest genera on the planet, boasting (probably) over 800 species (Friesen et al. 2006, Hirschegger et al. 2009, Mashayehki and Columbus 2014), with most species clustered around central Asia or western North America. Like all of the very speciose genera, Allium includes tremendous variation and internal evolutionary diversification within the genus, and 15 monophyletic (derived from a single common ancestor) subgenera within Allium are currently recognized (Friesen et al. 2006). Only a few have commonly cultivated (or wildharvested by me) species, however, shown on the phylogeny below. Continue reading
Posted in Uncategorized
Tagged allium, amaryllidaceae, angiosperm, Brassica, Brassicaceae, chemistry, chive, convergence, crucifer, defense, garlic, greens, Jeanne L. D. Osnas, leek, onion, phylogeny, ramp, recipe, sulfur, vegetable
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
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
Posted in Flavor, Recipes, The basics, Uncategorized
Tagged angiosperm, evolution, flavor, gluten free, pepper, phylogeny, recipe, spices
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
Posted in Uncategorized
Tagged alkaloid, caffeine, chocolate, Citrus, coffee, defense, guarana, holly, Ilex, Jeanne L. D. Osnas, phylogeny, tea, theobromine, theophylline, xanthine, yerba maté
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
Posted in Fruit, Uncategorized
Tagged billberry, blueberry, cranberry, Ericaceae, fruit, huckleberry, Jeanne L. D. Osnas, lingonberry, pectin, phylogeny, Vaccinium
The story of the nightshades is usually told as a tale of European explorers, New World agriculturalists, and a wary bunch of Old World eaters. But what about the birds? And the goji berries? Jeanne and Katherine introduce you to the Solanaceae family and walk you through the botany to be observed while making ratatouille, the classic French collision of Eastern and Western nightshades.
Can you imagine Italian cuisine without tomatoes? The Irish without potatoes? Chinese cuisine without spicy, fruity chiles? Such was the case prior to the discovery of the New World nightshades (family Solanaceae) by sixteenth-century Spanish explorers. And they couldn’t help but run into them. Solanaceae is a huge family, with over 100 genera and nearly 2500 species, most of which are in Central and South America. Continue reading
Posted in Fruit, Recipes, Uncategorized, Vegetables
Tagged chile, eggplant, fruit structure, goji, ground cherry, Jeanne L. D. Osnas, Katherine Preston, nightshade, pepper, phylogeny, ratatouille, recipe, Solanaceae, tobacco, tomato