Senna occidentalis (Cassia occidentalis)
(Senna comes from an Arabic name, occidentalis means western.)
John and I focused literally today around Jensen Beach, Florida. Arguably the most noteworthy species on today’s agenda is Septicweed, aka Coffee Senna, a super-weed. Its nativity, like so many global weeds, is murky, reputedly hot-climate America. The plant has compound leaves, yellow flowers, and flattened bean pods. It can flower and fruit as a little herb underfoot, or can grow into a shrub taller than you are. The plant has a ton of history in human affairs in food, in beverage, in medicine, in pastures, and more.
The name Coffee Senna gives a clue as to one historical applications, the seeds roasted as a hot beverage.
The name Septiweed probably refers to the stinky crushed foliage resembling a festering wound, which brings us to its medicinal history. Name a pathogen you’d like to eliminate…and somebody somewhere has published an article documenting Senna occidentalis to do the job: cancer cells, fungi, insects, malarial sporozoans, nematodes, sleeping sickness trypanosomes, and more. Wow. An all-purpose hit plant. Laxative as well (although not the Senna in the commercial laxative Senokot.)
Viewed in a medical context it kills everything, yet seen through an ethnobotanical lens, it is gift from nature as food, drink, and remedy? A dilemma, and a great case to underscore the silly argument, of “people have been eating this for a long time, so it’s nature’s bounty!” Natural is good for you! (CLICK for dangerous BS.) Simplistic thinking makes the world go round. Fact is, plant’s live in a chemical warfare race against their pests and have evolved an arsenal. There is no clear line between “edible” and “toxic” plants. Mother Nature doesn’t think that way. Even long-domesticated grocery store species, such as celery, can retain residual nasty….you know, just like the commercials tell us our Boston Terriers still have the soul of a meat-craving wolf.
Maybe roasting those seeds for the fake coffee helps with detox, but I don’t take total comfort in that, and any non-roasted ingestion is manifestly dangerous. The scary problem with “plants that must be great because granny used them for tea” can take the form of under-perceived chronic, or sporadic, or low-level, or inconsistent, or localized, or mis-attributed damage. In historical cultures where the weazened elders were 30 chronic toxicity may have escaped notice. Everybody smoked happily in the 1940s. Consider this example of human fatalities pinned on Septicweed seeds after initial misattribution of the cause of illness. (CLICKITY CLICK)
Ask the neighborhood veterinarian. Septicweed has poisoned livestock right here in Florida. It destroys mitochondria. With exceptions including bacteria, most living creatures need mitochondria for converting food energy to cell fuel to power basic functions such as muscle contractions. Livestock and lab animals poisoned by Septicweed suffer mitochondrial loss entailing muscle damage entailing heart failure. Maybe limited non-lethal heart failure could take the form of fatigue, or shortened lifespan, I dunno, I’m no veterinarian, but I do have a heart and mitochondria, ixnay on the epticsay.
Although tough to generalize worldwide, the plant’s basic business model seems according to limited research to be germination upon arrival of a rainy season, growing up lickety split, and depositing seeds into the soil seed bank for the next rainy season. Observers have noted a puny root system, given that the species depends on fast use of ample water, and waiting out drier times as a rootless seed.
And to end on a weird note, according to biologists Robert Fleet and Brenda Young, today’s species has an unholy collusion with fire ants. Foliar glands nurture the little demons who defend the Senna from caterpillars unconcerned about their mitochondrial integrity. After the blog was posted, Linda Cooper mentioned seeing Sleepy Orange and Cloudless Sulfur butterflies in large numbers breeding on today’s weed.