Seedbox, Bushy Seedbox, Bushy Waterprimrose
Synonyms of Ludwigia alternifolia (14) (Updated on 3-16-21 from Plants of the World Online): Isnardia alternifolia (L.) DC., Isnardia alternifolia var. salicifolia (Poir.) DC., Isnardia alternifolia var. uniflora (Raf.) DC., Isnardia aurantiaca DC., Ludwigia alternifolia var. linearifolia Britton, Ludwigia alternifolia var. pubescens E.J.Palmer & Steyerm., Ludwigia alternifolia var. typica Munz, Ludwigia angustifolia var. ramosissima (Walter) Poir., Ludwigia aurantiaca Raf., Ludwigia macrocarpa Michx., Ludwigia microcarpa Link, Ludwigia pruinosa Raf., Ludwigia ramosissima Walter, Ludwigia salicifolia Poir.
Ludwigia alternifolia L. is the correct and accepted scientific name for this species of Ludwigia. The genus and species were described as such by Carl von Linnaeus on the first volume of the first edition of species Plantarum in 1753.
Plants of the World Online lists 81 species in the Ludwigia genus (as of 5-16-21 when I last updated this page). It is a member of the plant family Onagraceae with a total of 21 genera. Those numbers could change as updates are made by POWO.
The distribution map for Ludwigia alternifolia is from the USDA Plants Database. The map on Plants of the World doesn’t show as many states as the USDA Plants Database. The species may be more widespread than even this map shows.
The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations.
THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.
I found this good-sized colony of Ludwigia alternifolia in the back of the farm by the pond on September 1, 2019 while I was wildflower hunting. The first thing that caught my attention were the square-like seed pods. There were barely any flowers to be found.
The stems of the Ludwigia alternifolia can be light green, red, brown, or even nearly white. As the plant ages, their bark will split near the base of the stems. Most of the plants had multiple branches. Ummm… The yellow flowers in the photo are not from this species… 🙂
Single yellow flowers emerge from the axils from the upper leaves on short pedicles from green bractlets that may have short hairs. The yellow flowers have 4 petals, 4 light green sepals, 4 short stamens, a pistol with a short style. The problem with finding flowers is that they only last for a single day and fall off easily.
The lance-shaped, hairless leaves grow in an alternate pattern along the stems. The leaves can grow to 4” long and 3/4” wide, are narrowly lanceolate, rounding at the tips, tapering at the base with short petioles. The leaves are light to medium green.
The stems were mostly hairless but some had a fuzzy appearance…
The odd seed capsules are nearly square the break into 4 parts to release the seeds.
I hoped to find these plants again in 2020, but for some reason, I couldn’t locate any. It is strange how I have been back on the farm since 2013 and I didn’t notice them until 2019. There were quite a few of them, so it wasn’t like they could just magically appear in 2019 without coming from somewhere. Then, why couldn’t I find them in 2020? I checked a number of times because I wanted to get better photos earlier in the season. They are supposed to flower from June through August. I will continue checking for them in 2021.
I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. I have grown over 500 different plants and 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 firstname.lastname@example.org. I would enjoy hearing from you especially if you notice something is a bit whacky.
NOTE: Plants of the World Online is the most up-to-date database. It is very hard for some to keep with name changes these days so you may find a few discrepancies between the websites. Just be patient. Hopefully, someday they will be in harmony. 🙂
FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
MISSOURI BOTANICAL GARDEN
USDA PLANTS DATABASE
LADY BIRD JOHNSON WILDFLOWER CENTER
KANSAS WILDFLOWERS AND GRASSES
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 (and if they update their sources or even read what they say). Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. 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 the most reliable and up-to-date plant database and they make updates on a regular basis. 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. 🙂