The flowering shrubs known as witch hazel are perhaps best known for their use in folk medicine and as a natural topical skin ointment. But the seeds are also of interest to biophysicists and engineers because witch hazel capsules can shoot them out at incredibly fast speeds, thanks to a built-in spring-loaded mechanism. Researchers at Duke University have figured out why—contrary to expectations—the seed launch speeds are roughly the same, even though seeds across species can have substantially different masses. They described their results in a new paper published in the Journal of the Royal Society Interface.

“People ask me all the time, ‘Why are you looking at seed-shooting plants?’” said co-author Justin Jorge , a graduate student at Duke. “It’s the weirdness of their springs. When we think of springy things, we typically think of rubber bands, coils, or archery bows. But in biology, we have all these weird, complex shapes. Perhaps there are some benefits to these shapes that can be used to improve the design of synthetic springs, such as those used in small jumping robots, but first we need to understand how these biological springs work.”

According to Jorge and his co-author, advisor Sheila Patek, there are countless examples of biological springs in nature spanning a wide range of size scales and functions, including froghoppers, cannonball fungus, and carnivorous bladderwort plant traps—all of which use those mechanisms to launch projectiles. Trap-jaw ants use spring actuation to launch their mandibles to capture prey, while grasshoppers use their springy legs to kick away predators. Both species, as well as the froghopper, can also use the mechanism to launch their bodies. And flowering plants like the witch hazel use spring actuation to launch seeds out of their fruits.

Enlarge / A newly developed measuring device allows researchers to measure the electrical signal in the lobe of the Venus flytrap. (credit: Thor Balkhed/Linköping University)

Human beings and other animals send electrical signals via the central nervous system. The Venus flytrap, which lacks such a nervous system, also sends rapid electrical impulses, which are generated in response to touch or stress. It's how the plant traps its prey to feed. Now scientists have developed a bioelectronic device to better understand the Venus flytrap's complex signaling mechanism by mapping how those signals propagate, according to a recent paper published in the journal Science Advances.

“We can now say with certainty that the electrical signal originates in the sensory hairs of the Venus flytrap," said co-author Eleni Stavrinidou of Linköping University in Sweden. "With our technology, we can also see that the signal mainly spreads radially from the hair, without any clear direction."

As we've reported previously, the Venus flytrap attracts its prey with a pleasing fruity scent. When an insect lands on a leaf, it stimulates the highly sensitive trigger hairs that line the leaf. When the pressure becomes strong enough to bend those hairs, the plant will snap its leaves shut and trap the insect inside. Long cilia grab and hold the insect in place, much like fingers, as the plant begins to secrete digestive juices. The insect is digested slowly over five to 12 days, after which the trap reopens, releasing the dried-out husk of the insect into the wind.

In 2011, a horticulturist named Mathias Maier stumbled across an unusual mutant of a Venus flytrap , a carnivorous plant that traps and feeds on insects. Scientists recently discovered that the typical Venus flytrap can actually "count" to five, sparking further research on how the plant manages this remarkable feat. The mutant flytrap might hold the key. According to a new paper published in the journal Current Biology, this mutant flytrap doesn't snap closed in response to stimulation like typical Venus flytraps.

"This mutant has obviously forgotten how to count, which is why I named it Dyscalculia (DYSC)," said co-author Rainer Hedrich , a biophysicist at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany. (It had previously been called "ERROR.")

As we've reported previously, the Venus flytrap attracts its prey with a pleasing fruity scent. When an insect lands on a leaf, it stimulates the highly sensitive trigger hairs that line the leaf. When the pressure becomes strong enough to bend those hairs, the plant will snap its leaves shut and trap the insect inside. Long cilia grab and hold the insect in place, much like fingers, as the plant begins to secrete digestive juices. The insect is digested slowly over five to 12 days, after which the trap reopens, releasing the dried-out husk of the insect into the wind.

The iPhone can now recognise and identify numerous subjects, one of which is plants! This little known feature is useful in a few ways. Obviously, keen gardeners and plant lovers can now simply take an image of a flower they like, look it up instantly (or when it suits them) and then go buy one for themselves, all without needing to ask for or remember the grandiose Latin name. 

So actually this did not work on my iPhone 12 Pro, but the Google Photos app (on the iPhone) did in fact do a lookup and worked. (at least my wife says it is correctly identified, as I have no clue which plant is which).

See https://www.tomsguide.com/how-to/how-to-identify-plants-on-iphone

#technology #botany #iOS #plants