Tag Archives: Brassicales

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

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