Host and Guests – Ludwigia

I have a goal to identify all the species living on our farm.  The pond plants in particular have been a problem for me, because a lot of them look similar.  And even though I own a lot of special interest field guides, on things like toxic plants, aquatic plants, and weeds of the Texas rangelands, I haven’t been able to find them in those books.

A few weeks ago, I started making a concerted effort to identify this one — it sprouts up in new locations each year, it grows to about five feet tall, it has willow-like leaves, and small yellow flowers about one inch across.  Its most iconic feature is long thin seed tubes.

One of the mystery plants, a shrub about 5 feet tall.

Tall strong growth habit. And I just now saw the katydid at the top.

Six petals with long thin seed tubes.

Somewhere in the past I had gotten the idea that this was called Mexican seedbox, but online information didn’t match exactly with what I was seeing.  Features that I would expect to be consistent, weren’t.  Most of the time the flowers had six or seven petals; but often only four.  And I noticed two different shapes and sizes of the seed boxes — one was about two inches long and very thin; the other was about an inch long and squattier.  I’m no scientist, so I didn’t even know if plants could do that, but to me it seemed as strange as if cucumbers and peppers were growing on the same plant.

Four petals and a visiting bee.

Six petals and a visiting bee.

Infinitesimal seeds packed in to the long tube seed box.

A much shorter and stockier seed box.

Finally I realized that two closely-related plants are growing intertwined with each other!  Once I started looking more closely, I realized that the second one has graceful, flexible stems, that allowed it to sort of blend in with the taller, stalkier plant.

Comparison of the two Ludwigia plants.

Finally I found this very descriptive post which leads me to believe that the tall shrubby plant is anglestem primrose-willow, Ludwigia leptocarpa.  It could be Mexican primrose-willow, Ludwigia octovalvis, described here at the Lady Bird Johnson Wildflower Center site — but the plant growing here has hairy stems and six to seven petals, which fits the leptocarpa profile. But I am not sure.

The second one could be cylindricfruit primrose-willow, Ludwigia glandulosa Walter, or possibly another one from a long list at the USDA (I can’t link to the search results there). Going through that list, I saw a picture of Ludwigia alternifolia, and realized that plant grows here also, so that makes three!  No wonder I was confused.

Three Ludwigia species. I think they are,L to R: L. leptocarpa, L. glandulosa, L. alternifolia.

So for weeks I have been looking online for information, then going out to check the plants for matching features, then reading again, then checking again — and during that time I have seen so many creatures living on the Ludwigia species.  I have really enjoyed checking them a few times a day, and even at night, to see what I can find.

And then that leads to more rounds of identity-checking, but for insects instead of plants.  You can click on the pictures to see a larger image.

Eastern Lubber Grasshopper, Romalea microptera. This grasshopper has been in the same place on the very same plant for 11 days running.

An anole.

A young katydid.

A katydid, as yet unidentified.

A tiny wasp.

A different tiny wasp.

The ubiquitous love bugs, Plecia neartica.

Katydid at night.

Another anole, hidden among the leaves.

A Great Egret against a backdrop of Ludwigia.

A Green Lynx spider with an egg case. I have spotted two of these on the plants.

Another view, showing the cottony egg case.

A well-camouflaged Green Lynx spider takes an American Bumblebee.

Two weeks later, another bumblebee loses out to the spider.

A spectacular Banded Sphinx moth larva, Eumorpha fasciatus.

I love how the pattern looks like a row of turtle heads.

When the larva grows up, it will look like this. Banded Sphinx moth at

I have really enjoyed my daily check-ins with these plants!