NOTE: I made a mistake and thought the C. communis var. communis was C. erecta, and the plants with the dark spots were C. communis var. communis. However, the plants with the dark spots are C. communis var. ludens, and what I thought was C. erecta are actually C. communis var. communis…

Asiatic Day Flower

Commelina communis 

(Commelina comminis var. ludens)

kom-uh-LIN-uh/kom-uh-LEE-nuh  KOM-yoo-nis

 Synonyms of Commelina communis var. ludens (2) (Updated on 12-13-23 from Plants of the World Online): Commelina debilis Ledib. (1811), Commelina ludens Miq. (1861)

Commelina communis L. is the accepted scientific name for this species of Commelina. It was named and described as such by Carl von Linnaeus in the first edition of Species Plantarum in 1753.

Accepted infraspecific names (2)(Updated on 12-13-23): Commelina communis var. communis (type specimen), Commelina communis var. ludens (Miq.) C.B.Clarke. When a form, variety (variant), or subspecies is named an autonym (“type specimen”) is automatically named that is closest to the species.

Commelina communis var. ludens (Miq.) C.B.Clarke is the accepted infraspecific name for this species of Commelina communis. It was named and described as such by Charles Baron Clarke in Monographiae Phanerogamarum Prodromi nunc Continuato in 1881. It was first named Commelina ludens by Friedrich Anton Wilhelm Miquel in Journal de Botanique Néerlandaise in 1861.

The genus, Commelina Plum. ex L., was described as such by Carl von Linnaeus in the first edition of Species Plantarum in 1753. Mr. Linnaeus noted that the genus had been previously named and described by Charles Plumier.

As of 12-13-23 when this page was last updated, Plants of the World Online lists 201 species in the Commelina genus. It is a member of the plant family Commelinaceae with 36 genera. Those numbers could change as updates are made on POWO.

The above map from Plants of the World Online shows where Commelina communis is native in green and purple where it has been introduced. Commelina communis var. ludens has a MUCH smaller range. The USDA Plants Database shows a similar map of the United States but also includes the state of Washington. 

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.

2019 was a great year for identifying wildflowers on the farm. I took photos of Dayflowers in 2018 but I was just barely getting started identifying the wildflowers here. In 2019, I decided to ID as many as possible but got fairly busy at a friend’s farm. It wasn’t until the end of August that I took the first photos of Commelina communis var. ludens and I didn’t see any C. communis var. communis until September 1.

The Commelina communis var. communis were in a very large colony along kind of a ditch where the pasture drains into that leads to the pond. At first, I was checking their flowers sterile anthers for reddish-brown dots which is a characteristic of C. communis var. ludens. There was a strange problem… The spath-like bracts the flowers emerge from of Commelina erecta are supposed to be closed while the bracts of C. communis are supposed to be open. However, all the flowers in this colony were open instead of closed… The flowers had light blue petals like C. erecta and no reddish-brown dots… So why were their bracts open instead of closed? That’s because the colony with light blue flowers and no dots was C. communis var. communis and NOT C. erecta…

Finally, on September 1 as I was leaving the area, I looked down on the left side of where I went in and spotted a few plants with darker blue flowers. I took a closer look and low and behold the sterile anthers had reddish-brown spots. I had found Commelina communis var. ludens! But, something was weird! Their bracts were fused together where they should have been open! I thought maybe I had them backward even though I was sure I knew what I was looking for. After I took several photos, I went back inside to check. Sure enough, Commelina communis are supposed to have open bracts. That is one of the feature characteristics that separate it from C. erecta, besides having the reddish-brown spots. As I said, I screwed up… The spathe-like bracts are CLOSED not NOT fused

Flowers emerge from a heart-shaped bract called a spathe (spathelike bract) which is attached to the stem by a peduncle. One to three flowers will be produced inside the spathe. Normally the flowers will open in succession but I have seen two at the same time.

The two upper petals of C. communis var. ludens are a darker, true blue.

The above photo shows the difference between Comellina communis var. ludens on the left and Commelina var. communis on the right. The three sterile anthers AND the three lower fertile anthers of the C. communis var. ludens have reddish-brown spots.

I originally thought the the flower on the right was from a colony of Commelina erecta (Whitemouth Dayflower), but thanks to an expert on iNaturalist I was convinced otherwise. That explained A LOT!

The above photo shows what appears to be a fused bract on the C. communis var. ludens on the left and an open bract on the C. communis var. communis on the right. C. communis bracts are supposed to be open while C. erecta are fused. Hmmm… The expert on iNaturalist told me that even though the bracts appear to be closed, on close inspection they aren’t actually fused… I thought something was really whacky! How could they be reversed? Well, they are correct for C. communis var. communis and C. communis var. ludens.

On September 18 I noticed a few Commelina communis var. ludens near the swampy area in the southeast corner of the farm. These flowers had open bracts like they were supposed to. As flowers start to emerge, the “closed” bracts open…

I have read that Commelina species compete for pollinators so it is rare two species grow in the same area. Although there are both C. communis var. communis and C. communis var. ludens growing fairly close to one another in the one lot, they are not growing among each other.

Good photo of the three sterile anthers with the reddish-brown spots.

The above photo shows two spent flowers and visible ovaries which will turn into fruit that produce the seeds.

Like a couple of babies…

For so long I never really understood how a species can have a variety with the same name such as Commelina communis var communis. Steyermark’s Flora of Missouri refers to this variety as the “common var. communis” and says their upper petals are 10-15 mm long, has glabrous leaf sheaths, its anthers, false anthers and staminodes are all yellow. PLUS, he writes the false anthers “lack a reddish-brown spot”…

As far as the other variety, Commelina communis var. ludens, is concerned… Steyermark’s says this variety has “purple” upper petals, 8-10 mm long, PLUS the anthers and false anthers have purplish-brown spots in the middle of the staminodes. Then he writes, “Plants with purple petals are uncommon and sporadic throughout the state” (Missouri), “but sometimes have all yellow anthers and false anthers”…

While Commelina communis var. ludens is an accepted infraspecific name, many believe it should be considered synonymous with C. communis because of the difficulty in distinguishing the two. It is a highly variable species… Some say Commelina communis var. ludens have darker and larger flowers, and this and that…

I will also point out that botanical terminology and descriptions can make one scratch their hair out (which is one reason I shave my head). The author of the Wikipedia article (see link below) did an AWESOME job explaining the scientific terminology.

Commelina communis is considered an annual plant with slender, fibrous roots. Stems are fairly erect until they get longer then they become descending or decumbent (sprawly) and they can root at the leaf nodes. The sheaths on the leaf nodes can be glaucous and have white hairs near the tips. Leaves are kind of lance-shaped (lanceolate) to narrowly ovate.

The flowers… Well, as I mentioned, they are normally blue, and purple is quite rare. All websites say one of the distinguishing features of “the species” is the reddish-brown spots in the center of the staminodes on the anthers and false anthers. But, in light of what Steyermark’s says, that may not always be the case.

So, for argument’s sake and to make it simple, let’s assume that Commelina communis var. ludens have two upper blue petals and a smaller white lower petal, reddish-brown spots on the staminodes of the false anthers, and the spathelike bracts are supposed to be open the entire length. Well, they can be closed but NOT fused. You may have to pry them open. GEEZ!

Over the past couple of years I have only seen the Commelina communis var. ludens growing next to the lagoon and around the house. I haven’t seen a single Commelina diffusa or C. communis var. communis since 2019…

I also have a page for Commelina diffusa (Spreading Dayflower) and Commelina communis var. communis (Asiatic Dayflower) if you are interested.

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 species of wildflowers (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. 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.

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)
USDA PLANTS DATABASE
iNATURALIST
DAVE’S GARDEN
MISSOURI PLANTS
MSU-MIDWEST WEEDS AND WILDFLOWERS
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
WILDFLOWERSEARCH
PFAF (PLANTS FOR A FUTURE)
IOWA PLANTS
GO BOTANY
HOME, YARD & GARDEN PEST NEWSLETTER
WILD FOODIES

NOTE: The data 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. 🙂