"Long before it's in the papers"
February 15, 2016

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Ancient flowering plant was beautiful—and likely poisonous, scientists say

Feb. 15, 2016
Courtesy of Oregon State University
and World Science staff


Sci­en­tists are re­port­ing the first dis­cov­ery of fos­sil­ized “as­terids”—a family of flow­er­ing plants that gave us eve­ry­thing from the po­ta­to to toma­toes, to­bac­co, petu­nias and our morn­ing cup of cof­fee.

But these an­cient flow­ers, per­fectly pre­served in am­ber, came from the dark side of the as­ter­id fam­i­ly, re­search­ers say. They be­long to a ge­nus, or sub-lin­eage with­in an ev­o­lu­tion­ary fam­i­ly, that ul­ti­mately gave rise to some of the world’s most fa­mous poi­sons.

An asterid flower trapped in am­ber. (Pho­to by George Poi­n­ar, Jr., cour­tesy of Ore­gon State U.)


The find­ing sug­gests that poi­sons that would lat­er find their way in­to blow-gun weap­ons, rat con­trol, Sher­lock Holmes sto­ries and the mov­ie “Psy­cho” had some of their an­ces­tral and bi­o­log­i­cal roots in the pre­his­tor­ic jun­gles of what’s now the Do­min­i­can Re­pub­lic, re­search­ers say.

Flow­ers with­in the ge­nus Strych­nos, as it’s called, gave rise to poi­sons in­clud­ing strych­nine and cu­ra­re. The two newly dis­cov­ered flow­ers are es­ti­mat­ed as 20 mil­lion to 30 mil­lion years old.

They’re “beau­ti­ful, per­fectly pre­served fos­sil flow­ers, which at one point in time were borne by plants that lived in a steamy trop­i­cal for­est with both large and small trees, climb­ing vines, palms, grasses and oth­er vege­ta­t­ion,” said George Poi­nar of the Col­lege of Sci­ence at Or­e­gon State Un­ivers­ity, an ex­pert on or­gan­isms trapped in am­ber.

The flow­ers, of a pre­vious­ly un­known spe­cies, re­veal that “as­ter­ids, which lat­er gave hu­mans all types of foods and oth­er prod­ucts, were al­ready evolv­ing many mil­lions of years ago,” he added.

The study is pub­lished in the jour­nal Na­ture Plants. Co-author Le­na Struwe of Rut­gers Un­i­vers­ity in New Jer­sey named the species Strych­nos electri, from elek­tron, the Greek word for amber.

As­ter­ids, the au­thors not­ed, are among the most im­por­tant and di­verse plants, com­pris­ing about 80,000 spe­cies clas­si­fied with­in with 98 fam­i­lies and 10 or­ders. They rep­re­sent an es­ti­mat­ed one-third of all the Earth’s di­vers­ity of flow­er­ing plants, called an­gio­sperms.

And one an­cient ge­nus, now known as in­her­ently tox­ic, lived for mil­lions of years be­fore hu­mans, re­search­ers say. “Species of the ge­nus Strych­nos are al­most all tox­ic in some way,” Poinar said. “Each plant has its own al­ka­loids,” a type of ni­tro­gen-con­tain­ing or­gan­ic com­pound. 

These have “vary­ing ef­fects,” he con­tin­ued. “Some are more tox­ic than oth­ers, and it may be that they were suc­cess­ful be­cause their poi­sons of­fered some de­fense” against plant-eaters. “To­day some of these tox­ins have been shown to pos­sess use­ful and even me­dic­i­nal prop­er­ties.”

As nat­u­ral poi­sons that hu­mans came to un­der­stand and use, two ex­tracts from plants in the Strych­nos ge­nus ul­ti­mately be­came fa­mous: strych­nine and cu­ra­re.

Strych­nine had prac­ti­cal uses for dec­ades as a pes­ti­cide, and was of­ten the deadly com­po­nent of rat poi­son. But it al­so cap­tured the ima­gina­t­ion of writ­ers, and was used by Nor­man Bates in the mov­ie “Psy­cho” to kill his moth­er and her male com­pan­ion. In small doses, it can in­crease men­tal and mus­cu­lar ac­ti­vity.

Cu­ra­re has an even strang­er his­to­ry. Sir Wal­ter Ra­leigh may have first en­coun­tered it in 1596 when he ob­served poi­son ar­rows in South Amer­i­ca, where na­tives al­so de­vel­oped the poi­son in blow-gun darts to par­a­lyze hunt­ed prey. Cu­ra­re was fea­tured as the mur­der weap­on in one Sher­lock Holmes nov­el, and in low­er doses it has been used as a mus­cle re­lax­ant in sur­gery.

There are now about 200 spe­cies of Strych­nos plants around the world, in forms rang­ing from shrubs to trees and woody climb­ing vines, mostly in the trop­ics. They are still be­ing stud­ied for me­dic­i­nal prop­er­ties, such as for the treat­ment of par­a­sit­ic worm in­fec­tions and even as drugs to treat ma­lar­ia.

The dis­cov­ery of these two flow­ers, re­search­ers said, sug­gests that many oth­er re­lat­ed plant fam­i­lies could have evolved in the Late Cre­ta­ceous—the tail end of the dino­saur era—in trop­i­cal for­ests. But their fos­sils await dis­cov­ery.


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Scientists are reporting the first discovery of fossil specimens of an “asterid”—a family of flowering plants that gave us everything from the potato to tomatoes, tobacco, petunias and our morning cup of coffee. But these ancient flowers, perfectly preserved in amber, came from the dark side of the asterid family, researchers say. They belong to a genus, or sub-lineage within an evolutionary family, that ultimately gave rise to some of the world’s most famous poisons. The finding suggests that poisons that would later find their way into blow-gun weapons, rat control, Sherlock Holmes stories and the movie “Psycho” had some of their ancestral and biological roots in the prehistoric jungles of what’s now the Dominican Republic, researchers say. Flowers within the genus Strychnos, as it’s called, gave rise to poisons including strychnine and curare. The two newly discovered flowers are estimated as 20 million to 30 million years old. They’re “beautiful, perfectly preserved fossil flowers, which at one point in time were borne by plants that lived in a steamy tropical forest with both large and small trees, climbing vines, palms, grasses and other vegetation,” said George Poinar of the College of Science at Oregon State University, an expert on plant and animal life forms preserved in amber. “Specimens such as this are what give us insights into the ecology of ecosystems in the distant past,” he added. “It shows that the asterids, which later gave humans all types of foods and other products, were already evolving many millions of years ago.” The study is published in the journal Nature Plants. Asterids, the authors noted, are among the most important and diverse plants, comprising about 80,000 species classified within with 98 families and 10 orders. They represent an estimated one-third of all the Earth’s diversity of flowering plants, called angiosperms. And one ancient genus, now known as inherently toxic, lived for millions of years before humans, researchers say. “Species of the genus Strychnos are almost all toxic in some way,” Poinar said. “Each plant has its own alkaloids,” a type of nitrogen-containing organic compound. These have “varying effects,” he continued. “Some are more toxic than others, and it may be that they were successful because their poisons offered some defense” against plant-eaters. “Today some of these toxins have been shown to possess useful and even medicinal properties.” As natural poisons that humans came to understand and use, two extracts from plants in the Strychnos genus ultimately became famous: strychnine and curare. Strychnine had practical uses for decades as a pesticide, and was often the deadly component of rat poison. But it also captured the imagination of writers, and was used by Norman Bates in the movie “Psycho” to kill his mother and her male companion. In small doses, it can increase mental and muscular activity. Curare has an even stranger history. Sir Walter Raleigh may have first encountered it in 1596 when he observed poison arrows in South America, where natives also developed the poison in blow-gun darts to paralyze hunted prey. Curare was featured as the murder weapon in one Sherlock Holmes novel, and in lower doses it has been used as a muscle relaxant in surgery. There are now about 200 species of Strychnos plants around the world, in forms ranging from shrubs to trees and woody climbing vines, mostly in the tropics. They are still being studied for medicinal properties, such as for the treatment of parasitic worm infections and even as drugs to treat malaria. The discovery of these two fossil flowers, researchers said, suggests that many other related plant families could have evolved in the Late Cretaceous in tropical forests. Their fossil remains, however, still await discovery. The co-author of the study, Lena Struwe, is an expert on plants in the strychnine family, Loganaceae, and is a plant biologist at Rutgers University. researchers say