Wendy Langhans’ Santa Clarita Valley Outdoor Report, “The Ants Go Marching,” answers questions about flower pollination. In part II, Wendy answers the “why” ants go marching.
Two weeks ago, we took a closer look at the pollination of flowering plants by ants. We explored three reasons why it rarely occurs. This week, I’d like to address the follow-up question – if they are not there as pollinators, WHY DO THE ANTS GO MARCHING about on flowering plants?
(Photo courtesy: Steve Ioerger)
Foothill Penstemon. Note the ant in the upper right hand corner of the photo.
The answer is: they are attracted to the plant’s extrafloral nectaries.
Extrafloral nectaries are nectar-producing glands that are located outside the flower. Depending on the plant, extrafloral nectaries  can be found “on leaf margins, leaf axils, petioles, stipules, flower bracts, sepals and flower stalks. They may be conspicuous as raised glands or recessed basins and are sometimes colored differently than the surrounding plant material.” Click here to see photos of extra-floral nectaries.
Bush Sunflower. Extrafloral nectaries are found on sunflower stems.
Mexican Elderberry. Extrafloral nextaries are found at the base of the leaves.
Ants visit extrafloral nectaries for the same reason they visit the strawberry rhubarb pie sitting on your picnic table: they’re HUNGRY! Extrafloral nectaries produce sugary nectar, a watery liquid containing “a mixture of glucose, fructose, sucrose and some protein, amino acids and organic acids.”
But this offer of food comes with a price tag attached. Plants get PROTECTION in return. “The presence of the ants help to protect the plant from browsing and from insects laying eggs on the foliage, and experiments have shown that plants with ants do better than plants without.” In addition, there is some evidence  that ants protect plants against leaf pathogens.
Given this understanding of plant/ant cooperation, perhaps someone ought to revise the refrain in the classic children’s song, “The Ants Go Marching .”
How about, “And they all go marching up…to the plants…to defend them from harm…BOOM! BOOM! BOOM!”?
Free Birding App. For those of you who are looking for a good birding app for your Apple cellphone or iPad, the Cornell Lab of Ornithology is offering a free app. Click here  for more information.
Upcoming Outdoor Events:
Saturday, April 19, 8-10am. Spring Birding. With the weather changes and flowers blooming, now is the perfect time to discover which birds live and feed in our local mountains. Beginning birders are welcome. Binoculars optional. Meet at Towsley Canyon’s front parking lot. 2 hours. Click here  for map and directions.
Sunday, April 27, 2pm. Community Nature Series presents “Butterflies of Placerita Canyon.” Butterflies are all around us! They have been called “flying jewels” or “flying flowers.” Dr. Paul Levine will review the life cycle of butterflies and share photos of the many common butterflies found in our Santa Clarita Valley. Click here  for more information.
Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at firstname.lastname@example.org  for time and place.
Wednesday mornings, April 2, 9, 16, 23 and 30.
Saturday mornings, April 19.
New trail maps available. If you’d like to explore a bit on your own, the City of Santa Clarita has a website with trail maps  of our local open spaces.
There’s also a new website for bicycle riders .
Ask Dr. Norm : Do you have questions about the flora, fauna, animals, rocks, etc. in our Santa Clarita Valley? Here’s a place for you to ask your questions. Dr. Norman Herr, Ph.D., is a professor of science and computer education at CaliforniaStateUniversity, Northridge.
Tell Us About Your Hike : Here’s a new website where you can post pictures, provide feedback and make suggestions about the City of Santa Clarita’s trails and open spaces.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The SCV Outdoor Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
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