Commelina erecta-Whitemouth Dayflower

Commelina erecta (Whitemouth Dayflower) on 9-8-19, #504-18.

Whitemouth Dayflower, Widow’s Tears, Slender Dayflower, Scrub Dayflower

Commelina erecta

kom-uh-LIN-uh  ee-RECK-tuh

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

The genus, Commelina Plum. ex L., was described by Carl von Linnaeus in the first edition of Species Plantarum in 1753. It was first named and described by Charles Plumier then later described by Mr. Linnaeus citing Mr. Plumier’s previous description. Plants of the World Online list 200 accepted species in the Commelina genus.

Distribution map of Commelina erecta from Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/. Retrieved January 30, 2020.

The above distribution map of Commelina erecta from Plants of the World Online, by permission, shows where the species is native in green and introduced in purple. The species might be found in other areas as well and not been reported.

Please check the links at the bottom of the page for further reading and positive ID.

Commelina erecta (Whitemouth Dayflower) on 9-8-19, #504-19.

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 I could but I got fairly busy at a friend’s farm. It wasn’t until the end of August that I took the first photos of Commelina erecta and I didn’t see any C. communis until September 1.

The Commelina erecta were in a very large colony along kind of 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. There was a strange problem… The spath-like bracts the flowers emerge from on 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 and no reddish-brown dots like C. erecta… So why were their bracts open instead of closed?

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-1.

Flowers emerge from spathelike bracts at the top of the stems.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-2.

Flowers have two upper blue petals and a smaller white petal. Flowers have three false anthers and three fertile anthers. The petals are a lighter blue that C. communis and they have no reddish-brown spots.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-3.

Here again, the above photo shows an open bract instead of being fused at the lower third like it is supposed to be… The bract is folded so what looks like the lower part is actually the midrib.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-4.

NICE! Flowers open in succession, but many bracts have two flowers that are open at the same time. Flowers supposedly only last for one day.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-5.

I am running out of words to say about the flowers…

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-6.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-7.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-8.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-9.

The ovaries are where the seed is produced.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-10.

Leaves are lanceolate to slightly ovate and have a sheath that surrounds the stems. The sheaths have small white hairs. Leaves grow in an alternate pattern on the stems.

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-11.

Here is a better photo of the leaf sheaths…

 

Commelina erecta (Whitemouth Dayflower) on 8-29-19, #617-12.

 

Commelina communis on the left and Commelina erecta on the right on 9-1-19, #620-10.

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! But, something was weird! Their bracts were fused together where they should have been open! I thought maybe I had them backwards 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 sperate it from C. erects, besides having the reddish-brown spots.

 

Commelina communis on the left and Commelina erecta on the right on 9-1-19, #620-11.

The above photo shows the closed bracts on the C. communis on the left and open bracts of the C. erecta on the right. C. communis bracts are supposed to be open and C. erecta bracts are supposed to be closed… Hmmm…

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-1-19, #620-20.

Most information says Commelina erecta is considered an annual but Steyermark’s Flora of Missouri says they are perennial. Perhaps they are perennial in the southern part of Missouri and in the south. They have somewhat thickened, fibrous roots like a perennial would.

 

Commelina erecta (Whitemouth Dayflower) colony by the back pond on 9-7-19, #625-2.

Photo of the large colony of Commelina erecta by the pond in the back pasture. Commelina erecta, like other species in the genus, have erect to ascending stems. That means they grow upright until they get long enough to sprawl. Stems on the ground root at the nodes.

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-3.

I took a lot of photos of the flowers and bracts because they are the most interesting part of the plant.

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-4.

I opened this bract which shows two ovaries inside.

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-7.

The above is a good photo showing the flower with a short peduncle between the flower and ovary. Strange how Commelina erecta is supposed to have bracts that are fused tother, the lower third… How can they be fused together when a flower is coming out? They are probably fused together initially but open as it matures.

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-8.

The flowers are so neat I can’t help but taking a lot of photos of them. You never know when some of the photos are going to be blurry.

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-9.

AHHHHH. I looked at hundreds of flowers and bracts and FINALLY found this one with a fused bract!

 

Commelina erecta (Whitemouth Dayflower) by the back pond on 9-7-19, #625-10.

As you can see in the above photo, the bract is fused at the lower third, but a flower is starting to emerge next to the stem.

 

Commelina erecta (Whitemouth Dayflower) on 9-7-19, #625-11.

I will take photos of the leaves and stems of Commelina erecta in 2020. Many of the links below give better descriptions and photos.

I also have pages for Commelina diffusa (Spreading Dayflower) and Commelina erecta (Whitemouth Dayflower) if you are interested.

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. 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)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
DAVE’S GARDEN
*MISSOURI PLANTS*
*MSU-MIDWEST WEEDS AND WILDFLOWERS*
*iNATURALIST.ORG*
*WILDFLOWERSEARCH.ORG*
USDA PLANTS DATABASE
*ILLINOIS WILDFLOWERS*
MINNESOTA WILDFLOWERS
LADY BIRD JOHNSON WILDFLOWER CENTER
KANSAS WILDFLOWERS AND GRASSES
PFAF (PLANTS FOR A FUTURE)
USEFUL TROPICAL PLANTS
MICHIGAN STATE UNIVERSITY
NINNESCAH LIFE (WICHITA STATE UNIVERSITY
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