# Sensitive plant - Mimosa Pudica

1. Jul 26, 2010

### arydberg

Could someone please tell me how electric currents are conducted through the body. I understand that both Na and K ions are involved. Recentely I brought something called a "sensitive plant" (Mimosa Pudica) which folds up it's leaves when touched. I thought these same ions were involved but I may be wrong.

Last edited by a moderator: Jul 28, 2010
2. Jul 26, 2010

### jim mcnamara

3. Jul 27, 2010

### arydberg

Re: sensitive plant

Thanks for the help. "Thigmonasty" gives me somthing to follow up on.

4. Jul 27, 2010

### nismaratwork

Re: sensitive plant

Top answer your original question, Wikipedia actually has a decent article which describes the anatomy of a neuron, and in that how it conducts electrical current.

http://en.wikipedia.org/wiki/Neuron
Then: http://en.wikipedia.org/wiki/Ion_transporter
http://en.wikipedia.org/wiki/Ion_channel

What this is going to tell you is that there are "pumps" for so-called "electrolytes" of which Jim has mentioned a couple (Calcium, Potassium, and I would add Sodium (Na)) which allow for an imbalance in positive and negative charge within the neuron in regards to its surrounding medium. This is called the Action Potential, beyond this however the neuron waits for chemical signaling across the synaptic cleft from other neurons. At this point these organelles go into action, sending an electrical current through the Axon (just like any other conductive medium such as wire) which then triggers the neuron's own chemical signaling machinery, propagating the signaling to more neurons via neurotransmitters.

The rate of conduction through the axon can be increased with Myelin sheathing which acts as an insulation. Some neurons have a great deal of this, and others less, but you can understand from the above why demyelinating diseases are so devastating. You've almost certainly heard of Multiple Sclerosis, which is a well known demyelinating disease: http://en.wikipedia.org/wiki/Multiple_sclerosis

5. Jul 28, 2010

### Greg Bernhardt

Re: sensitive plant

Hate to hijack this thread a bit, but I love this plant! I found it trekking in both Costa Rica and Zanzibar. I am so fascinated by it! arydberg did you buy it for growing outside or inside? I live in a primary cold climate and would love a small pot inside for kicks!

6. Jul 28, 2010

### jim mcnamara

nismaratwork -

Higher plants don't have neurons. M. pudica has a oddball structure on the bottom of the petiole, that triggers an osmotic collapse of cells, sort of like an accordion. If I remember, it is thought to be seismonasty, an adaptation to make plants appear unpalatable to grazing animals. The vibrations of animal hooves will make the leaves droop, as will touch.

7. Jul 28, 2010

### nismaratwork

I know, but the title asked one question, and the OP asked another... you answered the plant question, so I figured that I would field the one regarding how electrical signals are conducted through the body. I assumed he didn't mean the body of a the plant in question.

8. Jul 28, 2010

### Staff: Mentor

Re: sensitive plant

You can get the plants or seeds from amazon.com. It's a common weed, you can't get rid of it down in Houston where I used to live, I have some growing outside my place here, but the gardeners keep mowing them down. They're commonly known as touch-me-nots.

http://www.amazon.com/Amazing-Sensitive-Plant-Leaves-Mimosa/dp/B0012YMHNQ

9. Jul 28, 2010

### turbo

Re: sensitive plant

Get some, Greg! They are very hardy! A botany student on the other side of my dorm had a window-box full of them on the inside sill. His room was on the north side of the dorm and never got direct sunlight. The window sills were clad in metal and got very cold in the winter, but his "sensitive" weeds thrived in cool environs with indirect light.

Last edited: Jul 28, 2010
10. Jul 28, 2010

### nismaratwork

Is the mechanism for action of this plant ultimately the same as others such as the Venus Fly-Trap? I realize in that case there are trigger filaments, but in terms of the contraction, it must be a similar or identical mechanism, yes?

11. Jul 28, 2010

### turbo

Don't know, but I have a favorite little "beach" on a trout pond near here that seems to be a great habitat for sundews. Sundews have sticky "fingers" on the tops of their leaves that look sweet and tasty to insects, and when a bug tries to sample the "dew" it gets stuck, and the leaf curls up around it to digest the bug. The sundews in that location seem to prefer growing on fallen cedar logs - wood that rots VERY slowly in this climate.

12. Jul 28, 2010

### nismaratwork

Hey, a plant needs to get its nitrogen.

13. Jul 28, 2010

### arydberg

I got mine by going to google and entering "tickle me plant" It is outside now but i will move it inside before the frost.

I have difficulty believing that this plant or cactus for that matter have defense measures against being consumed by animals. Most plants and animals share a reciprocal relationship where the plants are eaten by animals but then the remaining plants are fertilized by these same animals.

14. Jul 28, 2010

### Staff: Mentor

DO NOT buy from "tickle me", it is a marketing rip off!!!!

They want $19.99. The name is a marketing gimmick and has nothing to do with the plant. Go to the amazon.com link I provided above if you live in an area that this weed does not normally grow in. 15. Jul 28, 2010 ### arydberg I paid about$4.95 and about $3.00 for shipping. I got one package of about 20 seeds & had trouble getting them to grow. Now I have 2 plants from about 8 seeds i planted. There are more seeds left. They may not be the best but it worked for me. 16. Jul 28, 2010 ### Evo ### Staff: Mentor You can get a large packet of 80 seeds for$1.99.

17. Jul 30, 2010

### arydberg

Yours seems to be the better source.

Al

18. Aug 3, 2010

### arydberg

What I wanted to know relates to the signal that tells the leaves to close. Not how they close. I would like to know if this signal is similar to the signals that control our muscles in the human body.