This morning as I was walking down our driveway here in Potrerillos Arriba, Panama, to unlock the gate I noticed some beautiful pink flowers growing among the weeds. I’ve always loved flowering things. Perhaps I’m genetically disposed that way through my paternal grandfather who used to grow what were referred to as “cut flowers for the trade.” Not only did he have large fields of gladiolus of which he produced several new varieties, but he also had greenhouses though they were in ruins when I was young.
These flowers are those of the Mimosa pudica (pudica=shy).
Wikipedia describes the plant as a creeping annual or perennial herb often grown for its curiosity value: the compound leaves fold inward and droop when touched or shaken, re-opening minutes later. The species is native to South and Central America but is now a pantropical weed.
Mimosa pudica is well known for its rapid plant movement.
Like a number of other plant species, it undergoes changes in leaf orientation termed “sleep” or nyctinastic movement. The foliage closes during darkness and reopens in light.
The leaves also close under various other stimuli, such as touching, warming, blowing, or shaking. These types of movements have been termed seismonastic movements. The movement occurs when specific regions of cells lose turgor pressure, which is the force that is applied onto the cell wall by water within the cell vacuoles and other cell contents. When the plant is disturbed, specific regions on the stems are stimulated to release chemicals which force water out of the cell vacuoles and the water diffuses out of the cells, producing a loss of cell pressure and cell collapse; this differential turgidity between different regions of cells results in the closing of the leaflets and the collapse of the leaf petiole.
The plant has serious medicinal qualities because of its alkaloid called mimosine which has been found to have potent antiproliferative (used or tending to inhibit cell growth <antiproliferative effects on tumor cells) and apoptotic ( a genetically determined process of cell self-destruction that is marked by the fragmentation of nuclear DNA, is activated either by the presence of a stimulus or by the removal of a stimulus or suppressing agent, is a normal physiological process eliminating DNA-damaged, superfluous, or unwanted cells (as immune cells targeted against the self in the development of self-tolerance or larval cells in amphibians undergoing metamorphosis), and when halted (as by genetic mutation) may result in uncontrolled cell growth and tumor formation—called also programmed cell death) effects.
Its extract immobilizes the filariform larvae of Strongyloides stercoralis (threadworm) a nematode that can parasitize humans in less than one hour.
2 responses to “You Can Observe A Lot Just By Watching – Yogi Bera”
I’m so happy! I remember the tree with the leaves that closed when touched from my time in Africa, but I’ve never seen one since or known the name.
Now, it’s clear that your mimosa plant and my remembered trees are related. It was called a silk tree in Liberia, but it’s clearly the same – leaves, flowers, etc.
Great information about the actual process that causes the response.
And on top of everything else – it’s pretty 😉
In Panama we call them “dormilonas”. We used to play with them when kids. Brought back memories of my youth.