Of wild carrots and the death of Socrates

There is a plant I keep encountering, both on foraging trips and while out running, and for a long time I had been entertaining the hope that it was wild carrot (Daucus carota), while secretly suspecting that it was actually poison hemlock (Conium maculatum).  These two members of the Apiaceae/Umbelliferae family look very similar as young plants (and both are sometimes called Queen Anne’s lace), but armed with Samuel Thayer’s “Nature’s Garden” on our recent Redwood Park foraging trip, I was able to pin down once and for all that…dammit, yes: it’s hemlock.

Poison hemlock, Conium maculatum. Not the wild carrot I was hoping for. Photo courtesy of Jen at willblogforfood.

The Apiaceae are a fickle lot of plants: some are friendly foodstuffs (carrot, fennel, celery, parsley, caraway), some are vicious poisons (poison hemlock, water hemlock, fool’s parsley), and some are something in between (like cow parsnip, which is edible but whose sap can be a strong irritant).  Several of them look similar as young plants, too, with rosettes of feathery leaves and umbels of delicate white flowers.

Caraway, Carum carvi. If I hadn’t read the title, I might have thought it was fennel, because all these darn Apiaceae look similar. From Koehler’s Medizinal Pflanzen.

Over the centuries, many people have been poisoned by mixing them up.  A handful of case studies from the last decade of folks who ate a variety of toxic Apiaceae can be found  here, here, here, and here.  For those who forage, wild wood survival offers a sturdy guide to telling tasty wild carrot from its toxic doppleganger.  (Quick and dirty version: hemlock has smooth stems, sometimes speckled purple or with a chalky residue.  It doesn’t smell very good, and its flowers are loosely packed in umbels, like caraway, above.  Wild carrot has fuzzy stems, smells strongly of carrot, and has tightly-packed umbels of flowers with one dark purple flower in the middle.  And if you’re in doubt, don’t eat it!)

Wild carrot, Daucus carota. Similar enough to C. maculatum to give you pause, and make you wish you’d brought some store-bought carrot leaves along for comparison. Photo from Gunther Blaich’s website.

And then, of course, there are the more sinister, deliberate poisonings. Continue reading


These pink elephants are caused by what part of the absinthe, exactly?

Back in 2002 I went to Prague, where I was able to legally sample that storied vice of brooding 19th-century artists, absinthe.  The preferred method of preparation was to pour some of the liquor into a large spoon, add a pinch of sugar, and heat it over a candle flame until the sugar dissolved.  It was a ritual that added to the sense of participating in a dangerous, clandestine tradition, and coupled with the pre-Industrial-era architecture and cobblestone streets, I would leave the pub fully expecting to run into a Van Gogh-like figure, or at least hallucinate one.

"The absinthe drinker" being visited by the green fairy. By Czech painter Viktor Oliva, 1901.

Somewhat disappointingly, I never hallucinated any depressive one-eared artists.  Or anything else for that matter.  In fact, despite the 120-proof alcohol content, I only got modestly tipsy, thanks to the absinthe’s bitter, anise-y flavor (the origin for the word “absinthe” is likely the Greek apsinthion, which means “undrinkable”).  The one time I followed the absinthe up with a couple glasses of red wine, I did end up with a headache that might have inspired some gruesomely morbid poetry, but I wasn’t feeling moved by a creative impulse so much as by the impulse to find out what had happened to my Advil over the course of 3 flights and two layovers.

Fast forward to this past St. Patrick’s Day, when my friends brought over a bottle of appropriately green absinthe made and sold just a few miles away at our local distillery, St. George’s.  While the mystique was not so pronounced in my living room as it had been in a Czech pub, the product was definitely the same: the bottle confidently proclaimed that it contained extracts from wormwood (Artemisia absinthium, the plant that gives absinthe its distinctive flavor and color).  Ten years ago, I had to go to Europe for this stuff.  Why is it legal here now? Continue reading

How to Build a Giant.

After last week’s perusal of 4-winged dinosaurs, my labmates and I got into a bit of a competition to find the most outlandish prehistoric animal, which led us to meter-long millipedes, 2-foot mayflies, and something called Hallucigenia.  What most captured our attention was that arthropods in the Carboniferous period were terrifyingly enormous.  50lb scorpions? GAAAAHH!!

Pulmonoscorpius was 70cm long, and makes me feel a tad bit better about sharing the world with the puny little several-inch scorpions we get now. Artist's rendition by Nobu Tamura, via Wikipedia.

But then we realized the Carboniferous (about 350-300 million years ago) was the same period that gave us 50-foot horsetails and house-sized ferns, and we paused long enough to ask ourselves: “Wait, hang on.  Why was EVERYTHING so darned big back then?” Continue reading

Steel magnolias: using magnolol to combat arthritis

The gorgeous display of magnolia flowers around campus has been capturing my attention over the last few weeks, but it turns out they’re just as noteworthy for their therapeutic potential as for their aesthetics. A new article in press for PLoS One (open access for everyone!) describes a novel activity for the Magnolia officinalis derivative magnolol in repressing inflammation, which is a pretty tantalizing topic for a runner like me who’s always a little bit neurotic about the health of her joints.

Flowers of Magnolia x soulangiana, a cross between M. lilliflora and M. deundata.

Continue reading

Alliums: giving the immune system a smelly leg up

By February I am generally fed up with the cold and flu season, and this year is no exception.  Our household has been hit hard by a cold/bronchitis 1-2 punch, and we’ve been single-handedly keeping the makers of Ricola and our local Pho (Vietnamese chicken soup) shop financially solvent for the last few weeks.

It’s about this time that I start musing about zinc, antivirals, ICAM-1 inhibitors, VP4 protein based vaccines…in short, why the heck haven’t we found a way to beat the common cold?  Continue reading

Why “Natural” isn’t always better: almond extract and cyanide

Right now the various species of Prunus are in flower all over northern California; the ornamental plums that are so popular as sidewalk decor are shedding petals everywhere, apricot blossoms are peeking out from yards, and the almond trees that crop up as renegades from the big orchards near Davis and in the central valley are covered in popcorn-y pinkish white flowers.  With constant reminders of stone fruit everywhere but none actually in season to eat, I’ve been doing a lot of baking with almonds and almond extract.

A sprinkling of wild plum blossoms (Prunus americana) on my way to lab.

Continue reading

Bitter but beneficial: salicylic acid and willow bark

After the last half-marathon I ran two weeks ago my longer runs have been hampered a bit by a nagging inflammation in my right lower hip muscle (piriformis strain: it’s a pain in the butt).  I was reflecting on this mild misfortune this weekend as I was reaching the home stretch of a very pretty 12-miler near the water, which went right past a clump of willows in early flower.  (Salix lasiolepsis…I think.  Salix laevigata is also native here, but the loose open buds looked more like lasiolepsis).  This provided an ample reminder of the general awesomeness of willow bark’s key pharmaceutical component, salicylic acid, and its more famous derivative, acetylsalicylic acid.

Willows by the water: a stand of flowering Salix.

Willow flowers just past the fuzzy pussy-willow stage. These look right for S. lasiolepsis; S. laevigata flowers stay more compact and fuzzy.

Good for a whole range of what ails you:

One of the more well-publicized botanical myths is that aspirin comes from willow bark.  This is only a short hop from the truth.  The actual anti-inflammatory produced metabolically by willow is salicylic acid–depending on the species and time of year, willow bark contains between 0.08 – 12.6% salicin, the metabolic precursor of salicylic acid.  Salicylic acid (historically purified in large quantities by boiling the bark of white willow, Salix alba) is readily acetylated into acetylsalicylic acid, trademarked as Aspirin.  You might have made acetylsalicylic acid back in chemistry class, or you leave aspirin tablets somewhere damp, you might notice a vinegary smell as they hydrolyze back to salicylic acid and acetic acid. Curiously, while Bayer still holds the trademark on “Aspirin”, “aspirin” is generic.  A/aspirin (hmm…not sure what the trademark rule is on capitalization at the start of a sentence) is part of the NSAID group of anti-inflammatory drugs–useful at reducing fever and throbbing pain.   Aspirin also exerts a potent anticoagulant effect by inhibiting the platelet aggregant thromboxane, so many people take it to reduce the risk of stroke or blood clots following surgery.

Salicin and salicylic acid, found in willow bark, and acetylsalicylic acid, better known as aspirin.

Salicyclic acid is also anti-inflammatory but is probably more recognized for its antibiotic effects; it’s one of the most common topical treatments for the bacteria that cause acne.  This handy dermatological property is of course just a human co-option of the plant’s own defense system: salicylic acid is produced by plants in response to stress, and reduce their vulnerability to bacterial infection.

It’s not all good news though…

The reason we don’t take salicylic acid orally as a pain killer is partly because the pharmacokinetics are a little different from aspirin, but mostly because salicylic acid is very rough on the stomach.  Acetylsalicylic acid is less irritating (for reasons I have been hard-pressed to discern–it’s a weaker acid, but at stomach acid pH that shouldn’t make a difference), but it can still cause ulcers and stomach bleeding if taken in too high an amount or with other NSAIDs.  What’s more, the conjugate base of salicylic acid, salicylate, is damaging to the hair cells of the inner ear in some people (salicylate sensitivity).  Chronic aspirin consumption can cause tinnitus when the acetylsalicylic acid hydrolyzes back to salicylic acid in the bloodstream.

Extra nitty gritty: this bitter pill to swallow has a pleasant aftertaste

So. Pretty versatile, right?  A quick hunt through the scientific literature for salicylic acid entries yields a complex mixture of rheumatology, dermatology, cardiology, botany, auditory and gustatory references.

Wait, gustatory…?  Yes.  Because as you know if you’ve ever had the misfortune of having to down an aspirin without a glass of water, salicylic acid and acetylsalicylic acid taste just awful–they’re the very definition of bitter.  This was, in fact, a significant hitch in marketing acetylsalicylic acid early in its commercial development, and pharmacologists tried out a range of less effective and even toxic variants to try to make it more palatable before resigning themselves to just mixing it into a sugary syrup or coating the pills.

Curiously, the bitterness of salicylic acid and its derivatives has become an independent asset to science, because they’re the perfect compounds to study the physiology and chemistry underlying bitter taste detection.  Salicin (basically salicylic acid with a glucose ether instead of a carboxylic acid) was recently used to study the crystal structure of the “bitterness” taste receptor hTAS2R16.

Why aspirin tastes so bad: two proposed models for the interaction of salicin (blue) with key amino acids (green) in the bitterness taste receptor hTAS2R16. From Sakurai et al., J. Biol Chem 2010.

So if you find yourself near fresh water in the next couple weeks, enjoy the budding willows, but don’t take a bite out of the bark.