Urena lobata

Malvaceae

Some time ago the featured pantropical invasive plant in this blog was Caesarweed, Urena lobata. 

Caesarweed grows around the tropical world, sharing multiple interfaces with humanity:

1. It is a source of fibers, perhaps how it came to Florida.

2. It is a one-plant chemistry lab, and is all over the world of plant-based traditional medicines.

3. Its burrs stick like VELCRO all over your cuffs.

4. It is a pesky weed.

Time now to revisit from a different angle…the back sides of the leaves have a nectar gland where the leaf stalk joins the blade.  

In the plant world such “extrafloral nectaries” are not rate, and they are generally interpreted to be primarily there to feed ants who clear the plants of pests.    Caeserweed does have ants, but that is just the beginning.   On a warm sunny day if you hang out around Caeserweed you find it to be an insect social center.   They come like Black Friday shoppers to the Treasure Coast Mall, interacting with each other, and systematically visiting the leaf glands, over and over.

By the way, it is not just ants and wasps,  even spiders are known to drink the sweet nectar.  But back to the wasps.   Here is a gallery of visitors today, plus a short movie of one walking from gland to gland.

Click for very short wasp action flick