Tag Archives: Brassicaceae

Maca: A Valentine’s Day Call for Comparative Biology

Sometimes food is medicine, and sometimes that medicine is an aphrodisiac. Such is the case with Andean staple maca. What elevates this high-altitude root vegetable above its cruciferous brethren?

The ancient Greek Hippocrates, the father of modern medicine, famously said: “Let food be your medicine.” For most of human history, categorizing an edible item as either food or medicine could prove difficult or impossible (Totelin 2015). Even in the current era of modern pharmaceuticals, food and medicine exist along a continuum (Johns 1996; Etkin 2006; Valussi & Scirè 2012; Leonti 2012; Totelin 2015). The traditional Andean food Maca (Lepidium meyenii; family Brassicaceae) can be placed squarely in the middle of that continuum. Herbal medicine markets outside of its native Peru have recently discovered maca and loudly and lucratively promote an aspect of maca’s medicinal reputation that has particular relevance on Valentine’s Day: an aphrodisiac that increases stamina and fertility (Balick & Lee 2002; Wang et al. 2007). Continue reading

Throwback Thursday Thanksgiving feast

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!

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Alliums, Brimstone Tart, and the raison d’etre of spices

If it smells like onion or garlic, it’s in the genus Allium, and it smells that way because of an ancient arms raceThose 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 alliums

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garlic curing

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

Caterpillars on my crucifers: friends or foes?

A high glucosinolate (putatively anti-cancer) broccoli variety is now on the market.  Jeanne wonders if caterpillar herbivory-induced increases in glucosinolates can match it.  The answer is unsatisfyingly complicated. 

Cabbage butterfly pupa on the tile above my sink. A survivor from washing crucifers from the garden.

Cabbage butterfly pupa on the tile above my sink. A survivor from washing crucifers from the garden.

There are three primary reasons why I haven’t launched aggressive war on the cabbage butterfly (Pieris rapae) caterpillars munching on the cruciferous veggies in my garden, even though I don’t like them:  (1) garden neglect; (2) hostility towards most pesticides; and (3) bonhomie toward caterpillars by my toddler.  There is also a fourth reason.  I know that in general most plants increase production of chemical defense compounds when they detect that they’re being attacked by pathogens or herbivores (Textor and Gershenzon 2009).  Some of these defense compounds have been shown to be beneficial for human health, including those in crucifers.  I’ve been wondering for a while if those caterpillars were actually enhancing the value of the tissue they didn’t consume.  A recent report about a high-defense-compound laden variety of broccoli prompted me to do some research into the issue.  I’m left with more questions than answers. Continue reading

The most political vegetables: A whirlwind tour of the edible crucifers

arugula

Jeanne provides an overview of the cultivated brassicas.

Two days after the re-election of Barack Obama, the arugula at the farmer’s market reminded me of John Schwenkler’s excellent commentary from the 2008 campaign season on political trends in food choices, taking issue with Republican opposition to arugula. Arugula was the subject of a gaffe by then-candidate Obama.  Afterward the vegetable joined lattes in the pantheon of foodstuffs entirely in custody of liberals, according to some pundits on the political right.

broccoli

Arugula was not the only, or even the most recent, brassica (a species from the mustard family, Brassicaceae) to be dragged into the American political fray.  Marion Nestle has a great commentary on two memorable instances when broccoli entered national political discourse, first when George H. W. Bush disavowed the vegetable, and then recently when Antonin Scalia turned the vegetable into a symbol of government imperialism during the Supreme Court’s consideration of the Affordable Care Act.

cabbage

In July 1948 Truman called both houses of Congress back from recess for what is now known as the Turnip Day Session, starting on, as he said, “what we in Missouri call Turnip Day,” the 25th of July.  The designation comes from an old Missouri saying: “On the 25th of July, sow your turnips, wet or dry.”  During World War I sauerkraut in the United States for a time became “Liberty cabbage,” a marketing predecessor to the Freedom Fries in the George W. Bush-era congressional cafeteria.  The re-labeling came from American manufacturers of sauerkraut, the German name for the lacto-fermented salted cabbage popular in much of Europe and Asia, who worried that Americans would reject a product with a German name (incidentally, though smelly, making your own sauerkraut is easy and yields satisfying results).

watercress

The relative frequency of brassica appearances in political discourse reflects their abundance in the modern grocery cornucopia.  In previous posts we discussed the numerous varieties of Brassica oleracea (including kale, collard greens, Chinese broccoli, Brussels sprouts, kohlrabi, cabbage, broccoli, and cauliflower) and other Brassica species (turnips, rutabagas, rapini, napa cabbage, tatsoi, bok choy, mizuna, mustard greens, mustard seeds, mustard or canola oil).  This post completes our whirlwind tour of Brassicaceae food plant diversity. Continue reading

The extraordinary diversity of Brassica oleracea

Before the caterpillars attacked: Red Russian kale seedlings

Jeanne turns her frustration with caterpillars in her garden into an exploration of the botany behind an extraordinary species:  Brassica oleracea.

White cabbage butterflies (Lepidoptera: Pieris rapae) decimated the fall kale crop in our garden.  To be fair, the abundant green caterpillars did not consume the entire blade of every leaf.  The remaining nibbled leaves, however, in my husband’s view, no longer resembled food so much as a caterpillar farm that would be tedious to turn into food.  He ripped out the caterpillar farm, threw it on the compost bin, and replaced it with lettuce.  Unlike kale, which is in the mustard family (Brassicaceae), lettuce is in the sunflower family (Asteraceae) and is therefore not even remotely attractive to white cabbage butterflies.

Caterpillar damage on young green curly kale in the garden at Monticello

I was tempted to save the hole-riddled leaves from their compost fate, in part because I know that the munching of the caterpillars actually increased the foliar concentration of some of the compounds that contribute to kale’s nutritious reputation, and also because plummeting autumn temperatures impart an extraordinary sweetness to kale and the other cruciferous vegetables that are all actually varieties of the same species, Brassica oleracea: cauliflower, cabbage, kohlrabi, Brussels sprouts, Chinese broccoli, and collard greens.  The details of the chemical consequences of caterpillar consumption will soon get a post all their own.  This post is dedicated to the botany and evolutionary biology behind the amazing diversity of B. oleracea. Continue reading