Saturday, June 26, 2010


Yucca filamentosa is the flower for people who like white blossoms. This thick bodied bloom looks as if it were sculpted in a confectioners kitchen. This is a six parted flower, as evidenced by the number of petals and stamens.

Yucca is a plant native to the south-east United States, so Blue Jay Barrens is not within his natural range. In one context it would be considered a non-native invasive species, because it will spread and take over an area. However, there are other more tolerable categories into which this plant might fit. One of those is the idea of Heritage Species. These are plants that have played an important role in the lives of our ancestors and because of that, have earned a special place in the landscape.

Yucca grows in dry sandy or rocky soils. The fact that the natural range of this species is not terribly far from southern Ohio suggests that it could easily have become one of our native species without out help. Some sources cite historical accounts of settlers carrying the Yucca along with them to plant in their new homesteads. Other sources talk about Native Americans growing Yucca near their settlements and moving it with them as they migrated. The Yucca at Blue Jay Barrens grows on top of the cleared hill. As far as I can discover, no one knows of any cabin or dwelling being located anywhere on the hill. Serpent Mound is only a mile west of here, so maybe this was the historical local Yucca patch. I’ve been controlling the spread of the Yucca, but because of the possible historical significance of its presence here, it’s not slated for elimination.

The Yucca may not be native, but there’s something on the plant that attracts the Mound Builder Ants. While these guys were reacting to the proximity of the camera, several of their colony mates were gnawing on my ankles.

I found this stink bug probing around on the back side of a Yucca seed pod. It was trying to avoid me by scooting around the pod, but it ran into the flower stalk.

There is only one insect that can successfully pollinate the Yucca flower. The female Yucca moth makes a hole in the flower’s ovary into which she deposits her eggs. She then fills the hole with pollen, which results in fertilization and seed development. The developing moth larvae then feed on Yucca seeds. The plant needs the moth and the moth needs the plant, a condition known as mutualism.

Inside a growing seed pod are rows of developing seeds. I’ve never seen a Yucca moth or the larvae or any holes in the seed pods or seeds that look as though they had been nibbled. If moths are the sole pollinator, they must be present, because the plants produce seed every year and spread to new areas through the distribution of fertile seeds. Why is it that after several years of searching, I’ve never been able to find any evidence of this moth? Is there actually some other pollination mechanism at work here?


  1. Fascinating. I have Yucca plants in my yard and consider them invasive now because I just can't seem to keep them contained. One is fine, but when they try to take over an area, well, they are no longer so welcome. I learn so much here. Thank you.

  2. Lois - They do make attractive landscape plants and can grow to enormous size when given some good soil and a little care. They're not much fun though, if they won't stay put.

  3. That's a good question. As far as I know the yucca moths are the only documented pollinators for Yucca filamentosa, and abscission is much more likely if fruits are self-pollinated rather than outcrossed. I might have to start cutting open some fruits on the ones we have around here.

  4. My toddler daughter and I just today investigated this interesting plant we have had growing in our yard since we moved here. The first pod we opened had three moth larvae in it. They are a bright red/pink color and they certainly nibbled at the rows of seeds. :)

  5. I haven't seen anything like that yet. I wonder if those are the Yucca Moth.

  6. I just found your blog while researching ferns in the UK (go figure!) and I'm enjoying this happy accident! Is there are way to follow your blog via email? I'm a wordpress blogger and we have that function, but didn't see it here.
    and btw, i like your common sense approach to non-native species.

  7. Hi Karen. Sorry, I don't think Blogger offers a follow by email option.