A plant that preys on plants
Dodder (Cuscuta sp.) preys on other plants by coiling its slender orange strands around them, inserting tendrils, and drawing out nutrients. In this view from the Blackland Prairie in Pflugerville on May 4th the two preyed-on species were prairie bishop (Bifora americana) and greenthread (Thelesperma filifolium). I lay on the ground to get this towering perspective; the result justified my discomfort (we artists suffer for our work).
Once a dodder plant is nourished at the expense of its prey, it produces clusters of tiny cream-colored flowers, as you can see in the lower right quadrant of the second photograph. The greenthread flower head still looked normal but others that I saw nearby were shriveled and stunted from the predation.
© 2020 Steven Schwartzman
Portraits of Wildflowers 
A destructive plant, can do serious damage to food crops.
MichaelStephenWills
May 11, 2020 at 6:02 AM
That’s what I’ve heard. On the other hand, the twining orange strands, the clusters of flowers, the chaos among the preyed-upon plants, all have appeal for a nature photographer.
Steve Schwartzman
May 11, 2020 at 7:06 AM
Thanks for raising my awareness of this pest.
MichaelStephenWills
May 12, 2020 at 5:30 AM
Another interesting thing about dodder is that it soon loses all connection to the ground and lives only in the “canopy” of the plants it preys on.
Steve Schwartzman
May 12, 2020 at 6:00 AM
Shuddering…….I really don’t like parasites, either flora or fauna. Don’t stay on the ground too long for those great shots, you might become a buffet!
Roadtirement
May 11, 2020 at 7:26 AM
The main thing that nature photographers in central Texas become a buffet for is chiggers. Fortunately they’ve been late to arrive this year and are just now beginning to make their presence felt, so I had a gloriously itch-free April and first part of May taking a slew of pictures.
Steve Schwartzman
May 11, 2020 at 7:36 AM
I had never heard of Dodder, but I understand it exists just about everywhere. It also sounds like it is difficult to eradicate without affecting the host plant as well (unless one hand pulls it, and what a job that would be!). I appreciate your sufferings in order to photograph this predator.
Littlesundog
May 11, 2020 at 7:29 AM
Till I got interested in native plants in 1999 I’d never heard of dodder either. You seem to be right about the difficulty in getting rid of it without the collateral damage done to the preyed-upon species. As Michael pointed out in the first comment, dodder can be a bane of farmers. From my point of view, though, I’ve always found dodder intriguing as a subject for portraits.
Steve Schwartzman
May 11, 2020 at 7:43 AM
Oh, how sad to learn that there are predators of plants that kill other plants for nutrients! Great perspective on the first shot. Your extra effort produced this outstanding photo, Steve.
Peter Klopp
May 11, 2020 at 8:02 AM
For whatever reason, we’re not as used to thinking of plants that prey on plants as we are of animals that prey on other animals. With plants on plants, the prey has no chance of running away.
I’m, glad you like the perspective in the first picture. I do, too.
Steve Schwartzman
May 11, 2020 at 3:06 PM
Creepy but kinda fascinating.
Your post also has three pleasingly evocative plant names. “Prairie Bishop” suggests a stalwart, salt-of-the-earth type, praying instead of preying, ridin’ the range, preaching’ & schoolin’ the bad ‘uns. “Greenthread” sounds like a folk song, with verses added to make it into “Greensleeves.” Despite a name suggesting a feeble, unsteady elderly person, I was just reading that “Dodder” moves pretty darn fast when it locates a victim.
The article said that last name may come from the Dutch for “egg yolk,” because of the yellow color (?)
Robert Parker
May 11, 2020 at 9:31 AM
When I learned about dodder two decades ago I did the same searching for the origin of the name that you did, and came across the hypothesis about the link to the Dutch word for ‘egg yolk,’ based on dodder’s color.
Prairie bishop is also known as prairie bishop’s weed. I used to call it that, but given how pretty its flower colonies are, this year I avoided the “weed” part of the name. The “prairie” in the name distinguishes this wildflower from a similar-looking one that colonists knew from England. Apparently the clusters of white flowers resembled the lace that Anglican bishops wore.
Good play on words with pray and prey.
Steve Schwartzman
May 11, 2020 at 3:18 PM
“I lay on the ground to get this towering perspective” – that’s the true photographer! 😉
Pit
May 11, 2020 at 9:33 AM
Then I’m a very tried and true photographer. I’ve been lying down to get nature pictures for twenty years. I alway carry a rubber mat with me to make lying and kneeling on the ground easier.
Steve Schwartzman
May 11, 2020 at 3:20 PM
The rubber mat is a very good idea. I may have asked you this before, but if your camera doesn’t have an articulated viewing screen, have you considered a right-angle finder? They are life- and back-savers!
krikitarts
May 11, 2020 at 3:55 PM
You’re right that my camera doesn’t have an articulated viewing screen. I’ll have to look into a right-angle finder (pun intended).
Steve Schwartzman
May 11, 2020 at 4:25 PM
Murder and mayhem in the natural world. Compellingly documented.
Michael Scandling
May 11, 2020 at 10:18 AM
Lots of mayhem goes on in nature; it’s common to find one thing attacking another. Photographically, dodder is an appealing subject.
Steve Schwartzman
May 11, 2020 at 3:23 PM
No question on both points.
Michael Scandling
May 11, 2020 at 4:09 PM
Your comment raises a pointed question. Why is ! called either an exclamation point or an exclamation mark, while ? is always called a question mark and never a question point? After all, both symbols include a point at their base.
Steve Schwartzman
May 11, 2020 at 4:34 PM
I think the word “point” sounds more exclamatory than “mark.” Just my guess.
Michael Scandling
May 11, 2020 at 4:55 PM
Sounds like you’ve gotten right to the point.
Steve Schwartzman
May 11, 2020 at 6:48 PM
!
Michael Scandling
May 11, 2020 at 8:15 PM
¡
Steve Schwartzman
May 12, 2020 at 6:17 AM
I think I’ve read that most conflicts between plants is more territorial than actual physical contact but Dodder is one of the exceptions, I guess. Interesting word as most often when I hear the word dodder I hope that it isn’t a description of my future.
Steve Gingold
May 11, 2020 at 6:08 PM
Like you, I wondered about the plant’s connection to the verb when I became acquainted with dodder 20 years ago. I looked into it then and learned that the dodder that’s a parasitic plant is a different word from the dodder that you’re worrying might describe you.
Steve Schwartzman
May 11, 2020 at 6:51 PM
And yes, with dodder there has to be physical contact or the dodder dies for lack of nutrition.
Steve Schwartzman
May 11, 2020 at 6:54 PM
Mahalo for sharing info on another bully in the wildscape.
Yoli
May 11, 2020 at 7:07 PM
Noʻu ka hauʻoli.
Steve Schwartzman
May 11, 2020 at 8:40 PM
A great resourceful plant. Not good, not bad, just is☺
We mere humans have such limited understanding of nature’s complexities.
Lovely images.
eremophila
May 12, 2020 at 5:55 AM
People are resourceful in turning nature to imaginative purposes. Here’s an account from around 1912 of an American Indian tradition: “The dodder vine was used by Pawnee maidens to divine whether their suitors were sincere. A girl having plucked a vine, with the thought of the young man in mind tossed the vine over her shoulder, into the weeds of host species of this dodder. Then, turning round, she marked the plant on which the vine fell. The second day after she would return to see whether the dodder had attached itself and was growing on the host. If so, she went away content with full assurance of her lover’s sincerity and faithfulness. If the dodder had not twined and attached itself, she took it as a warning not to trust him.”
Steve Schwartzman
May 12, 2020 at 6:07 AM
Fascinating, thank you.
eremophila
May 12, 2020 at 7:07 AM
You’re welcome. If you’d like to learn more about dodder, including the folklore involving it, you’re welcome to read an article I wrote:
https://npsot.org/wp/story/2017/9884/
Steve Schwartzman
May 12, 2020 at 7:18 AM
That’s sad and a bit scary! I have heard of plants crowding out other plants but not of this.
circadianreflections
May 12, 2020 at 1:45 PM
Yeah, it seems to come as a surprise to most people when they find out that plant-on-plant parasites exist. One of the best-known spring wildflowers in Texas, the Indian paintbrush, turns out to be a hemi-parasite, meaning that it produces its own nutrients but also steals some from adjacent plants.
Steve Schwartzman
May 12, 2020 at 2:27 PM
We have that wildflower here too. I had no idea it did that!
circadianreflections
May 12, 2020 at 2:28 PM
There’s more information about that in the question and answer at
https://www.wildflower.org/expert/show.php?id=3673
Steve Schwartzman
May 12, 2020 at 2:31 PM
I think I’ve seen this plant somewhere. It really preys on other plants!
Leif Price
May 13, 2020 at 12:36 AM
Yes it does. According to Wikipedia, there are over 200 species of dodder in the world’s temperate and tropical regions, so your chances of having seen some are good.
Steve Schwartzman
May 13, 2020 at 7:47 AM
Here’s a silly confusion: when I first came across dodder, I thought it was witch hazel, because the new, short strands were growing out of the stem of the host plant. Even after learning it’s a parasite, I still couldn’t wrap my mind around exactly how it works, but tonight I found an article that details it nicely:
“After germination at or near the soil surface, the seedlings grow quickly toward a host plant…coiling around any object it encounters. If a suitable host plant is not reached within 5-10 days the seedling will not survive. Once a suitable host plant is reached, the seedling wraps itself around the plant and produces special structures, modified adventitious roots called haustoria, that are inserted into the host’s vascular system. Once the dodder is established on the host plant its original root in the soil dies.”
“The dodder plant then continues to grow rapidly on that host plant, continually making new attachments to the host and eventually covering it – or spreading to adjacent plants – until the dodder plant is killed by frost. Since they have to re-establish from seedlings each year, species in temperate areas are only found in relatively low vegetation, whereas species in tropical areas, where plants can grow continuously, may reach high into the canopy of shrubs and trees.”
I still haven’t seen it in flower, so I especially enjoyed that aspect of your photos. The perspective’s wonderful, too; it’s good you were able to avoid the sort of chigger convention I encountered last week. It’s certainly no fun being the banquet for that kind of convention!
shoreacres
May 13, 2020 at 7:13 PM
I remember that word haustoria from reading similar articles about dodder a dozen years ago. What you’ve quoted is pretty similar to what I remember.
Someone I know who owns a property out near Lampasas said she has tree dodder there; I’ve never seen it anywhere.
Dodder flowers are so small and numerous, a sight to behold. I do hope you’ll get to see some for real.
The last time I got really badly chomped on by chiggers was last spring in Flower Mound. I then and you last week were in a wrong place at the wrong time.
Steve Schwartzman
May 13, 2020 at 9:05 PM
There are two places nearby where I’ve found good stands of it in the past. I’m going to stop by tomorrow and see what I can see.
shoreacres
May 13, 2020 at 9:21 PM
Happy flowers, we hope.
Steve Schwartzman
May 13, 2020 at 9:27 PM
Ew! That is such a mysterious plant. It appears in the strangest of places, causes so much damage before anyone notices, and then suddenly dies and disappears within only a few years. It does most of the damage shortly after getting established.
tonytomeo
May 14, 2020 at 9:53 AM
I’ve never had to look at the damage from the point of view of a farmer or gardener. As a nature photographer I’m free to appreciate dodder strictly visually, where it makes a compelling subject.
Steve Schwartzman
May 14, 2020 at 10:03 AM
Well, this one is certainly compelling.
tonytomeo
May 16, 2020 at 1:52 AM
It is, and I’m glad I took the time to get on the ground for the upward perspective.
Steve Schwartzman
May 16, 2020 at 8:07 AM
I shall remember that name..! Nature sure equipped this plant
Julie@frogpondfarm
May 16, 2020 at 2:44 PM
Surprisingly, it’s a member of the morning glory family.
Steve Schwartzman
May 16, 2020 at 2:51 PM