The extraordinary diversity of Brassica oleracea

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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 →

Varieties of the pepper experience

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Chili, black pepper, white pepper, and Sichuan pepper

Black pepper, pink peppercorns, chili pepper, Sichuan pepper – except for being “hot,” these spices have as little in common as Sergeant Pepper and Pepper Potts.  Their homelands are scattered across the world, and they were spread through distinct trade routes.  They are not closely related; they belong to families about as far apart as possible on the phylogenetic tree below.  They even aim their heat at different sensory receptors in your mouth. Continue reading →

Yellow freestone peaches, one with a bit of anthocyanin in its flesh

The Stone fruits of summer

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The scent of ripening peaches spurs Katherine’s musings on the botany
of stone fruits

Fragrant peaches ripening on window sills and countertops pull me right back into the heart of my childhood summers.  They always arrived in a huge box from Georgia, sent by my grandmother in the hope of drawing my parents back to their native state. Her other lures included Vidalia onions in April and Claxton fruitcakes in November, but peaches were definitely her best shot. The peaches were gorgeous, and their ripe flavor was incredibly complex and vivid, but their peak was ephemeral.  After my sister and I had spread them all out on newspapers, the whole sprawling array had to be checked at least two times a day and sorted by ripeness. Peaches were never allowed to touch each other.  On some hot days, peach tending took on the urgency of triage, with fruits passing from ripe to “sharp” to downright alcoholic in one long afternoon.

Peaches, nectarines, plums, apricots, and cherries are sometimes called stone fruits because of their pits, or stones.  Along with almonds, they are all in the genus Prunus which belongs to the Rose family – Rosaceae.  Several other familiar fruits come from the rose family but are not stone fruits. Continue reading →

Do peaches belong in the fridge?

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Some people just cannot bring themselves to refrigerate peaches. Storing peaches lovingly at room temperature is said to coax out the best in peach scent, flavor, and texture. But treating peaches this way does take a lot of time and vigilance, as I detail elsewhere. Reliable authorities – peach packing houses and state extension agencies – recommend refrigerating peaches once they become ripe, but some people would rather risk losing fruit to rot than let them get cold. But does it matter? Can peaches be stored in the fridge to slow their decline without compromising their peak? Continue reading →