Arnoglossum atriplicifolium (Pale Indian Plantain) on 7-8-21, #809-5.

Pale Indian Plantain

Arnoglossum atriplicifolium

arn-oh-GLOS-sum  at-ry-pliss-ih-FOH-lee-um

Synonyms of Arnoglossum atriplicifolium (13) Updated on 11-29-23 from Plants of the World Online): Adenimesa atriplicifolia (L.) Nieuwl., Cacalia atriplicifolia L., Cacalia atriplicifolia var. angulata Elliott, Cacalia paniculata Raf., Cacalia rotundifolia House, Cacalia similis J.Buchholz & E.J.Palmer, Conophora atriplicifolia (L.) Nieuwl., Conophora similis Nieuwl., Mesadenia atriplicifolia (L.) Raf., Mesadenia pulverulenta Raf., Mesadenia rotundifolia Raf., Mesadenia similis Small, Senecio atriplicifolius (L.) Hook.

Arnoglossum atriplicifolium (L.) H.Rob. is the accepted scientific name for the Pale Indian Plantain. It was named and described as such by Harold Ernest Robinson in Phytologia in 1974. It was first named Cacalia atriplicifolia by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753.

The genus, Arnoglossum Raf., was named and described as such by Constantine Samuel Rafinesque in Florula Ludoviciana (Flora of Louisiana) in 1817.

As of 11-29-23 when this page was last updated, Plants of the World Online by Kew lists 8 species in the Arnoglossum genus. It is a member of the plant family Asteraceae with 1,702 genera. Those numbers could change as updates are made by POWO. The number of genera in this family fluctuates often.

The above distribution map for Arnoglossum atriplicifolium is from the USDA Plants Database. The map on Plants of the World Online is similar but doesn’t show a few states. There are A LOT of maps with different data and different sources, but no map is perfect…

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. The maps on iNaturalist are continually updated as members post new observations. 

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

I first noticed this plant growing in the south hayfield along a HUGE mess of blackberry briars on October 4, 2018. I realized this was likely a rosette of leaves from a plant that would likely grow much taller in 2019.  Although I didn’t post the observation on iNaturalist at the time, I did use the drag-and-drop feature to see if it would suggest an ID from just a few leaves and no flowers. Amazingly, the suggested ID was Arnoglossum atriplicifolium… Commonly known as Pale Indian Plantain.

As I read about this species, I realized the photos I had taken were of a first-year plant. It wasn’t until 2021 I was able to watch several plants of this species grow through the flowering stage.

I have yet to figure out what that critter is on the leaf, but it was a great shot I couldn’t resist taking. I thought perhaps iNaturalist would suggest and ID for it rather than the species of the plant. Well, that didn’t happen…

Writing descriptions of plants in “layman’s” terms is sometimes very difficult. When I read technical descriptions I had to use the glossary on the Missouri Plants website to be able to understand what I was reading. As time went by, even though I understood what I was reading, I still had to refer back to the glossary to make sure I was writing descriptions correctly that made sense. I am not a botanist and I assume many of the readers of this page aren’t either.

Leaves of Arnoglossum atriplicifolium have long petioles. The leaves of first-year plants grow from an invisible caudex with fleshy roots. The long petioles have an adaxial (upper surface) groove and are often purplish toward the base. We have a lot to learn about this plant.

As the above photo shows, there is NO stem and this photo was taken in October…

<<<<2019>>>>

After winter was over and spring arrived in 2019, I wasted no time getting back to the south hayfield to see if this mysterious plant had returned. Sure enough, by May 1 this plant was growing a stem…

The area where this plant is (was) growing is in the south hayfield on the edge of a HUGE mess of blackberry briars, small trees, Japanese Honeysuckle, etc. The jungle runs almost the entire length of the 10 acres that is parallel to the Katy Trail which used to be the Rock Island Railroad. Once the grass starts growing, it is very hard to walk through the hayfield during the summer. I got busy doing this and that and didn’t go back to have a look until after the hay was cut. Unfortunately, I didn’t see anything resembling this plant…

2020 came and I didn’t see this plant at all. A friend of mine started leasing the pasture and hayfield in 2019. In November 2020, he had the blackberry patch and the whole mess cut down and built a new fence. It was the first step to getting this area under control.

<<<<2021>>>>

With the blackberry briars mowed down, many wildflower species I hadn’t seen growing before in this area were allowed to grow. To my amazement, there were several Arnoglossum atriplicifolium getting off to a good start by the time I took the above photo on June 15, 2021. It was kind of late in the day by the time I got to them to get good photos but I wasn’t ready to head to the house…

In the above photo, you can see a nice basal rosette of leaves from possibly a second-year plant…

Single round (terete) stems arise from a short caudex (woody base) among the basal leaves. The smooth (glabrous)) stems can be green to pale purple and have a waxy coating (glaucous).

The dark green basal leaves are broadly triangular with coarse teeth and prominent veins…

The undersides of the leaves are pale greenish-white to white…

The upper photo is of a plant with no stem…

I went back earlier on June 16 to get better photos of the Arnoglossum atriplicifolium. There is only so much you can do in the dark…

Some of the plants were so tall already it was hard to get a good photo of the whole plant. The leaves grow in an alternate pattern along the stems. The lower leaves can grow to at least 8″ long and 8″ wide and become smaller as they grow up the stem.

A few insects like their leaves…

The above photo shows a purple stem with a waxy coating and the leaves with long petioles.

The species grows from a single stem but starts to branch out at the top where the stems of the inflorescence (flower stem) start to grow.

There were A LOT of younger first-year plants which have lance-shaped leaves with sharp, prominent teeth. I wasn’t sure they were even the same species until I saw the undersides of the leaves…

I went back for more photos on July 8 to see how they were progressing. There were only two plants old enough to grow flower stems and start to bud. Of course, I was taking photos of other wildflowers, too…

The above photo is a typical leaf from about halfway up the stem. They are broadly triangular with deep lobes…

The underside of the same leaf…

I am kind of running out of words, but you get the picture…

The stems terminate with kind of a flat-topped panicle (corymb) of flowers with several smaller clusters on the side.

The inflorescence contains 4-15 flower heads per cluster. The flowers are tubular and have 4-5 disc florets but no ray florets…

A good-sized colony of first-year plants…

 

Yep… They have leaves with white undersides which is a sure-fire feature of Arnoglossum atriplicifolium…

 

I kept going back every few days to see if I could get photos of open flowers… It helps to have photos when you write descriptions… Well, that didn’t happen…

I kept waiting and waiting. The next thing I knew, the flowers on the inside of the cluster were wilted and the outside buds had done nothing. As time progressed, the blackberry vines had grown so tall AGAIN that I couldn’t get to these plants. GEEZ!

There are a couple more photos at the bottom of the page.

I live on a small farm in Windsor, Missouri where I enjoy gardening, collecting plants, and identifying wildflowers. The farm is in Pettis County but Henry County is across the street, and Benton and Johnson aren’t far away. I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of the page). 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 few horticulturalists 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)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
FLORA OF MISSOURI (GENUS/SPECIES)
FLORA OF NORTH AMERICA (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
WORLD PLANTS
USDA PLANTS DATABASE
DAVE’S GARDEN
MISSOURI PLANTS
MISSOURI BOTANICAL GARDEN
MISSOURI DEPARTMENT OF CONSERVATION
iNATURALIST
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
IOWA PLANTS
NORTH CAROLINA STATE UNIVERSITY
PFAF (PLANTS FOR A FUTURE)
LADY BIRD JOHNSON WILDFLOWER CENTER
FRIENDS OF THE WILDFLOWER GARDEN
MARYLAND BIODIVERSITY PROJECT
NATIVE PLANTS OF THE CAROLINAS & GEORGIA

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 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 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. 🙂

A FEW MORE PHOTOS FROM 2023…