Floating Primrose Willow, Clove-Strip, Creeping Water Primrose, Water Primrose

Ludwigia peploides

(Ludwigia peploides subsp. glabrescens)

lud-WIG-ee-uh  pep-LOY-deez  gla-BRES-senz

Synonyms of Ludwigia peploides (4) (Updated on 12-21-23 from Plants of the World Online):  Jussiaea peploides Kunth, Jussiaea repens var. peploides (Kunth) Griseb., Ludwigia adscendens var. peploides (Kunth) H.Hara, Ludwigia clavellina var. peploides (Kunth) M.Gómez
Synonyms of Ludwigia peploides subsp. glabrescens (3) (Updated on 12-21-23 from POWO): Jussiaea repens var. glabrescens Kuntze, Ludwigia adscendens var. glabrescens (Kuntze) H.Hara, Ludwigia peploides var. glabrescens (Kuntze) Shinners

Ludwigia peploides (Kunth) P.H.Raven is the accepted scientific name for this species. It was named and described as such by Peter Hamilton Raven in Reinwardtia in 1964. It was first named and described as Jussiaea peploides by Karl (Carl) Sigismund Kunth in Nova Genera et Species Plantarum in 1823.

Ludwigia peploides subsp. glabrescens (Kuntze) P.H.Raven is the scientific name plants in Missouri are assigned to. It was named and described as such by Peter Hamilton Raven in Reinwardtia in 1964. It was first named Jussiaea repens var. glabrescens by Carl Ernst Otto Kuntze in Revisio Generum Plantarum in 1891.

Accepted infraspecific names of Ludwigia peploides (4): Ludwigia peploides subsp. glabrescens (Kuntze) P.H.Raven, Ludwigia peploides subsp. montevidensis (Spreng.) P.H.Raven, *Ludwigia peploides subsp. peploides (autonym), Ludwigia peploides subsp. stipulacea (Ohwi) P.H.Raven. When an infraspecific taxon is named, an autonym (type-specimen) is automatically generated which is the closest to the original species. All have their own list of synonyms. 

The genus, Ludwigia L., was named and described as such by Carl von Linnaeus in the first volume of the first edition of Species Plantarum in 1753. 

As of 12-21-23 when this page was last updated, Plants of the World Online lists 87 species in the Ludwigia genus. It is a member of the plant family Onagraceae with  22 genera. Those numbers could change periodically as updates are made on POWO.

The distribution map for Ludwigia peploides is from Plants of the World Online. Areas in green are where the species is native and purple is where it has been introduced. You can view their map for Ludwigia peploides subsp. glabrescens HERE. The maps on the USDA Plants Database are basically the same.

The map on iNaturalist shows where members have made observations. The link shows the map for the species as a whole. They have separate maps for the subspecies as well but most members have just posted their observations for the species (unless they know the difference already).

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.

For as long as I can remember, even as a kid when my grandparents lived here, Ludwigia peploides have grown on the main pond behind the barn and one of the ponds in the back pasture. For some reason, they haven’t grown in the pond in the front pasture or the second pond in the back pasture (which is next to the other one). I remember my grandpa dragging these plants out of the pond with a rake. I never heard him call them by name but I know he didn’t like them.

As I became more involved with identifying the wildflowers on my farm (and a few other areas), I decided I just as well find out what these water weeds were. They turned out to be the subspecies Ludwigia peploides subsp. glabrescens. The “official” common name is Floating Primrose Willow but it also goes by Clove-Strip, Creeping Water Primrose, Water Primrose, and likely others.

The Missouri Plants website says plants in Missouri are assigned to Ludwigia peploides subsp. glabrescens. It is found predominantly from Nebraska to New York, down to Texas through Florida. It is also now found in Puerto Rico. The species as a whole has a much broader range… Of course, no map is perfect…

As you can see from the map, Ludwigia peploides (and subspecies) are quite common in most of the United States as well as several other countries. Once they get in your pond, they soon try to take over.

The Floating Primrose Willow is a perennial aquatic plant with a fibrous and fleshy root system. Although the stems may only grow to about 3’ long, it seems like they could go on forever due to them rooting at their nodes if the stems have wet ground to sprawl on. That can happen during the summer when the water level goes down. Strangely, the root system produces small “bladders” that help them float… That sounds like an idea for a photo.

Ludwigia peploides prefer growing in full sun although they take over a small pond in the back of the farm where they are in the shade most of the day. They also prefer growing in the mud and have basically adapted to floating on the water. Weird how there is another pond right next to the one they like, in full sun, where this species has never grown. There are two other ponds on the farm. one they like that basically dries up over the summer, and the other is spring-fed that they aren’t too fond of.

The stems are round, slightly succulent, and spongy, and ascend at the tip. Emerging stems are sometimes somewhat hairy. Stems are green to reddish in color. The stems root at the lower leaf nodes if they are in contact with the soil. To be honest, this species can become a real pain in the neck…

The leaves grow in an alternate manner along the stems. Floating leaves are said to be glabrous (not hairy), shiny, broadly elliptic, broadly oblanceolate, broadly obovate, or nearly circular. They are tapered at the base and taper to and bluntly pointed at the tip. The leaves have smooth margins and short petioles (leaf stems) with small stipules where the petioles join the stem.

The flowers have 5 yellow petals which are surrounded by 5 light green sepals. They are connected to the stems by 1-3” pedicels (flower stems).

Flowers produce 10 stamens in 2 unequal whorls, yellow filaments, and a strange-looking yellow pistil in the center.

The flowers are pollinated by various species of bees.

The seed capsules contain 5 narrow cells with a row of seeds. These capsules open gradually.

Even though Ludwigia peploides can be a pain in the neck (especially if you are trying to fish along the shore), they provide nectar and pollen for bees, flies, skippers, and sometimes butterflies. Ducks feed on their seed and some insects feed on their leaves. The plants also provide cover for frogs and insects.

The pond behind the barn doesn’t hold that much water anymore because of an issue with the bank on the south side. After years of the cows walking a certain path, it created a ditch that just kept getting bigger. The Floating Primrose Willow likes it… This is the pond I remember grandpa dragging the plants out of the pond with a rake.

I have enjoyed photographing and learning about the many wildflowers growing on the family farm and in other areas. I have grown over 500 different plants and identified over 250 wildflower species (most have pages listed on the right side of the blog). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a horticulturalist I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.

I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at thebelmontrooster@yahoo.com. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE
(GENUS/SPECIES/SUBSP.)
INTERNATIONAL PLANT NAMES INDEX
(GENUS/SPECIES/SUBSP.)
TROPICOS (GENUS/SPECIES/SUBSP.)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE (SPECIES/SUBSP.)
DAVE’S GARDEN
MISSOURI PLANTS
iNATURALIST
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
IOWA PLANTS
KANSAS WILDFLOWERS AND GRASSES
BACKYARD NATURE
MARYLAND BIODIVERSITY

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and thousands of species to keep up with. Accepted scientific names change periodically and can be hard to keep with. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is one of the most reliable and up-to-date plant databases and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂