IN ANOTHER LIFE I WAS A SCIENTIST, but in this one I got all of the curiosity but none of the education. So when the topic of Stone Fruit Week loomed as the theme for Week 4 of the Third Annual Summer Fest recipe swap (see all the links below to more, more, more), my recessive scientist trait flared and I got to asking: What’s a stone fruit, anyhow? Read on for some fun genetic facts (and a recipe for what I refer to—being scientific, you know—as the universal solvent of all fruit desserts, clafoutis batter).

What’s a Stone Fruit?

WHAT WE CALL STONE FRUITS all grow on trees in the genus Prunus, and have a hard, stony pit inside them (their seed), with fleshy fruit around it—unlike so-called pome fruits (see below).

Apricots, cherries, nectarines, plums (and therefore prunes), and some interspecies hybrids of the above, like plumcots and pluots, are all stone fruits. So are peaches (like the ones in the 1940 harvesting photo by Lee Russell, in the Library of Congress archive, top, or just above in the print from Boston Public Library’s).

And then there’s the trick-question one, the stone fruit you think of as a nut. What’s that?

Almond, of course: Prunus dulcis.

What’s a Pome Fruit?

I KNOW, IT’S STONE FRUIT WEEK, but hey, this is interesting…and there will be a point made any moment (or so the headline promised).

Other popular edible tree-grown fruits in our neck of the world include the pome fruits—apples and pears, in the genus Malus and Pyrus, respectively. The word pome simply comes from the Latin word for fruit.

And here comes my point:

But They’re All Roses in Disguise!

STONE OR POME, THEY’RE ALL ROSES—meaning members of the Rose Family, or Rosaceae, and therefore all related.

That’s the overarching botanical “aha,” one that I knew but rarely thought about, and it goes a little farther:

Raspberries, blackberries and even strawberries are Rose Family relatives, too.

Sweet.

(Are you all still awake? Dessert will be served pretty soon, promise.)

Peach Is One Really Juicy Genome…

NOW JUST A DOLLOP MORE GENETICS (AS IN GENOMICS): Apparently the peach is one juicy genome, from a geneticist’s point of view, with a small number of chromosomes—8—and other cooperative aspects.

So over the last decade, on to mapping Prunus persica an international team of scientists went, and the Peach Genome Sequence was released on April 1 this year—the first genome completed in the Rosaceae family. North Carolina State, Washington State, and Clemson universities were all involved; a popular standard-size peach rootstock cultivar, ‘Lovell,’ was the specific plant whose genes were mapped.

The peach turns out to be a model genome species for understanding all the other Prunus—remember those are our stone fruits, from Lesson 1, above—as well as for other species in the Rosaceae, and is expected be useful to plant breeders who want to develop peaches and related plants with particular desirable characteristics.

Tada! Now…

Dessert, Anyone?

LAST YEAR I GAVE YOU MY (MARTHA-ADAPTED) RECIPE for clafoutis batter, or what I call the universal solvent for fruit desserts. This concoction, like a thin pancake batter, turns fresh fruit as diverse as clementines to cherries, strawberries to plums, and even some dried ones if you dare try, into a fast, easy but sophisticated final course. Experiment.

The recipe I always use (above, with peaches in it) is here.

And then I got lost recently again in Michel Roux’ astonishing book simply called “Eggs,” and found another I’m enjoying. His batter goes like this (and like Martha, he used ripe pitted cherries, 3/4 pound, and lots of butter to grease the baking pan they’re going in):

Clafoutis Batter from Michel Roux

Ingredients
2 eggs
generous ½ cup all-purpose flour
6 ½ Tbsp. butter, melted and cooled
1/3 cup granulated sugar (plus extra for top)
2/3 cup milk, cold
1 vanilla bean, split lengthwise (mea culpa, I use extract)
1 Tbsp. Kirsch (optional)

The Steps
Very lightly beat eggs in a bowl, and add flour.
Whisk in melted butter, and gradually mix in the sugar and milk.
(Scrape vanilla beans from pod into mix; add Kirsch. I added extract here.)
Generously grease an 8-inch, 2-inch-deep ovenproof pan (he uses 5 Tbsp. more butter), spread the cherries in the bottom, and pour batter over them.
Bake for 10 minutes at 400 degrees, then lower the oven to 350, and cut several more Tbsp. of butter onto the top before baking another 25 minutes or until set, and a knife inserted comes out clean.
Dust with the remaining sugar; let stand a bit, but serve warm.

If you don’t believe me, or Martha, or Michel— maybe Mark Bittman can convince you? (I only read recipes by cooks whose names start with M, apparently. Kidding.)

How You Can Join in Summer Fest:

So now it’s your turn: Have a recipe or tip that fits any of our weekly themes? Starting with our posts of Wednesday, July 28, for five Wednesdays, you can contribute in various ways, big or small.

Contribute a whole post, or a comment—whatever you wish. It’s meant to be fun, viral, fluid. No pressure, just delicious. The possibilities:

Simply leave your tip or recipe or favorite links in the comments below a Summer Fest post on my blog, and then go visit my collaborators and do the same.

The cross-blog event idea works best when you leave your recipe or favorite links (whether to your own blog or someone else’s) at all the host blogs. Yes, copy and paste them everywhere! That way, they are likely to be seen by the widest audience. Everyone benefits, and some pretty great dialog starts simmering.

Or think bigger: Publish entire posts of your own, if you wish, and grab the juicy Summer Fest 2010 tomato badge (illustrated by Matt of Mattbites.com).

The 2010 Schedule:

• Wednesday, July 28: CUKES AND ZUKES. Read it here.
• Wednesday, August 4: CORN. The story.
• Wednesday, August 11: HERBS-BEANS-AND-GREENS WEEK (any one or both/all, your choice).
• Wednesday, August 18: STONE FRUIT.
• Wednesday, August 25: TOMATO WEEK. How do you like them love apples?
• And then…more, more, more if you want it (potatoes? sweet potatoes? root veggies? winter squash?). You name it.

And in case I forget what week it is, won’t somebody remind me on Twitter? Thanks. We’ll be talking it up there, too.

That’s how a Summer Fest works.

This Week’s Stone Fruit Links

• Marilyn at Simmer Till Done: Cherry Apricot Pie with Ginger-Almond Crunch.
• Sara at Cooking Channel: Savory Stone Fruit recipes.
• Todd and Diane of White on Rice Couple: Riesling Poached Pluots.
• Caroline at The Wright Recipes: Ginger and Vanilla Poached Peaches.
• The FN Dish: Paula’s Perfect Peach Cobbler.
• Alison at Food2: Peachy Party Foods.
• Kelly at Just a Taste: Peaches & Cream Cupcakes.
• Liz on Healthy Eats: Puttin’ Up Peach Pickles, Compote and More.
• Food Network UK: How to Poach a Peach.
• Judy of Divina Cucina: Chocolate Amaretti Baked Apricots.
• The Gilded Fork: dossier & recipes featuring peaches, apricots, nectarines, plums, cherries, almonds, coconuts.
• Cate at Sweetnicks: Blueberry Peach Smoothies.
• Tara at Tea & Cookies: Making Peach Jam.
• Alana at Eating From the Ground Up: Stone fruit slump.
• Caron of San Diego Foodstuff: grilled peach parfait and coconut peach gazpacho.
• Paige at The Sister Project: A Summer Fruit Whatchamacallit (not a pie, not a crisp, but delicious).
• Tigress in a Jam: nectarine preserve with summer savory and white pepper.