How to Mix a Heart-Stopping Salad

One evening,  in the early summer of 2008, a Colorado sheriff's deputy named Jonathan Allen came home to find that his wife had made him a "special" dinner. Waiting on the table was his favorite spicy spaghetti dish and a big leafy bowl of salad.

As he told investigators later, the salad was surprisingly bitter. But his wife told him it was a "spring mix" and he assumed it contained another of those trendy herbs that people use to liven up their greens. At least, he thought that way until he ended up in the hospital suffering from severe stomach cramps and a wildly speeding heart.

After his stomach was pumped and the contents analyzed, that bitter herb turned out to be leaves from a familiar and beautiful ornamental shrub. Allen survived but he did not return to his home in the suburban Denver town of Golden. And just this week, 42-year-old Lisa Leigh Allen, pleaded guilty to felony assault on charges of drugging a victim with what  The Denver Post, called a "lethal plant."

I'll confess that the description made me laugh. There are, after all, so many potentially lethal plants. In a mere three months, this blog alone has catalogued dangerous vegetation from monkshood to Peace Lilies. And the plant in this case was the common foxglove which is, indeed, poisonous but also figures as a long time source of some important heart medications.

I'll give that away when I tell you that the common foxglove belongs to a family of plants with the Latin name of Digitalis. The plant that ended up in the Colorado deputy's summer salad is formally called Digitalis purpurea, but also goes by some wonderfully evocative common names such as Witch's Glove, Bloody Fingers, and Dead Man's Bells.

Plants in the Digitalis family are packed with sugar-rich organic molecules called glycosides  that can directly affect the rhythmic beat of  the heart. The most important of these is called digoxin, or sometimes just digitalis, and is used to treat cardiac arrhythmias and to strengthen contractions of the heart.. The knowledge that foxglove extracts affect the heart is nothing new - it was first reported in 1785 by a British physician named William Withering - but medical understanding of how it works is fairly recent.

For instance, digoxin (and a related compound digitoxin) are known to trigger a cascade of chemical reactions which increase the amount of calcium delivered to muscle cells, which it turn increased the strength of the muscular contractions - thus giving new power to weakened heart beat. Digitalis can also stimulate the nerves which regulate the internal pacing of the heart beat.

So that at the prescribed dose, digitalis is the opposite of lethal - a life-saving compound, in fact. But the proper dose is extremely small - which means that even a small amount is dangerous.  Early symptoms include nausea, stomach cramps, headaches and even hallucinations. But it won't surprise you to know that the worst effect of digitalis poisoning is on the heart - it's been known to slow the beat to a complete halt or speed it to a point of over-taxation.

So that Allen's symptoms - the stomach cramps, the racing heart beat - added a little more evidence to the case against his wife. You could argue that she had to be aware that the foxglove was poisonous - digitalis homicides are almost as old as Withering's discovery. But that part's a little hard to prove, absolutely.

The original charge against her was attempted homicide, but Lisa Lee Allen agreed to take a plea bargain agreement for the lesser offense of felony assault. Sentencing is scheduled for May 14.  Yet another reason to stay away from those lethal plants.