A plant that responds to touch

A newly planted Mimosa strigillosa

Simply Living
October 8, 2012

My Massachusetts-residing daughter is responsible for the acquisition of my most recent Florida native plant.

“Do you have any of those plants with the leaves that curl up when you touch them?” Jenny asked during a phone conversation. 

“You mean sensitive plant?  No, I don’t have any but I really like them,” I admitted.  “Maybe I’ll get some.”

It took several months but I finally did. 

During the last weekend in September, vendors were selling native wildflowers at Hickory Point Recreational Park during Lake County’s Wings and Wildlife Festival.  As I wandered from one display to another, I recalled Jenny’s question and honed in on the small pots of Mimosa strigillosa for sale. 

Also known as sensitive plant, powderpuff, sunshine mimosa, touch-me-not or sleeping grass, Mimosa strigillosa is a low-growing perennial in the legume family known for its touch-sensitive leaves and its sticky-looking pom-pom flower heads that are the size and shape of pink lollypops. 

Mimosa strigillosa is an entertaining plant to own, especially if you have young children.  I wouldn’t be surprised if Jenny asked me about them because she remembered stroking sensitive plants when she was little.  Much to a toddler’s delight, the tiniest touch immediately causes the leaves to fold inward.  You don’t even have to put a finger on Mimosa strigillosa to elicit a reaction.  A strong puff of air or a sprinkling of water accomplishes the same thing.  To a young child (or a young-at-heart adult) the fast transition can seem magical.

Like most magic, however, a trick or physiological explanation is often involved.  In the case of Mimosa strigillosa, it’s a little bit of both. 

The plant’s instant response to tactile stimulation is a defense mechanism employed to ward off potential threats.  Insects or animals that might bite into fresh leaves are less likely to nibble on greens that look wilted.  By changing its appearance when stimulated, Mimosa strigillosa fools predators into thinking it’s an unhealthy specimen.  However, the same characteristic has the opposite effect on people, especially little kids who thrill with the discovery of a plant that all but purrs when stroked.      

If children are drawn to Mimosa strigillosa for entertainment, butterflies come for a different reason.  They hover about because of the plant’s value as a food source.  Nectar in the pink pom-pom-shaped inflorescences draws a variety of butterflies to partake of the blossom’s sweetness before flying off to another source of botanical sustenance.  One yellow-winged beauty, however, does more than just sip and fly.  Little Sulphur butterfly (Pyrisitia lisa) uses Mimosa strigillosa as a host plant.  It stays long enough to lay eggs.

Little sulphur butterfly on firespike

 

Thanks to a reminder by my Massachusetts-based offspring, I have reacquainted myself with this fun-to-grow Florida native plant.  Over the next few months, I hope the three starts I planted will spread their roots to establish a mat of leaf-curling, pom-pom-studded flora to fill in the space beneath one section of our raised container garden.  If they do, they’ll provide me with many opportunities to introduce my grandchildren to the wonders of nature when they come to visit. 

And when Jenny comes to visit at the end of October, I’ll have something for her too.  I’ve put one plant aside just for Jenny because in addition to all its other attributes (ease of care, drought tolerance, pest-resistance, pretty flowers, folding leaves…) Mimosa stigillosa also makes a wonderful houseplant.  Jenny may not live in Florida, but that doesn’t mean she can’t take back with her a little bit of Florida’s sunshine mimosa.