There are several plants in North Texas that are parasitic. Meaning they need a host plant to survive. For example, mistletoe is one such plant. Today’s post will be about three less familiar species. Each has a different strategy.
First is Dodder (Cuscuta)! An easy one to identify to genus, but not so easy to species. Most of the time I just go with Dodder. 🙂 It looks like a tangled mess of orange string. At first glance, a person might mistake it for trash. “It is an ectoparasite and is categorized as holoparasitic plant, or a plant that is non-photosynthetic and is completely dependent on a host.” (Wikipedia)
The flowers and the seeds are easy to miss. So this parasitic plant starts out like any other plant from a seed. Then it roots. However, once it has found a host plant, it leaves its roots behind. It then inserts itself in the host plant’s vascular system. Furthermore once attached, it can not be eradicated because it is embedded inside the host plant. Some Dodders are host specific. If it can not find a suitable host, it will die. Wisconsin Horticulture site has some nice information on Cuscuta.
Second is the False Foxglove (Aureolariagrandiflora)! This plant is hemiparasitic or a plant that has chlorophyll and carries out photosynthesis. However it is partially parasitic on the roots in this case. In particular, white oaks!
Many insects visit the flowers including bumblebees, leaf-cutting bees, Syrphid flies and many others. An ant had business on this flower as well.
Here’s one that was fading.
When pressing this plant for herbaria specimen, Shirley always liked to warn you that it would turn black like this one has already.
A beautiful flower from any angle! While doing a bit of research on it, I found that it could be grown from seed! I never knew! “The preference is partial sun, mesic to dry conditions, sandy loam, clay-loam or rocky soil. The seeds should be planted near a host plant (a tree in the white oak group). This plant will not harm its host plant to any significant degree if the latter is larger in size than a sapling.” (https://www.illinoiswildflowers.info/savanna/plants/lf_fsfxglove.html) I might have to try it 😉 FYI, Post Oaks, Bur Oaks, and Chinkapins are among the white oaks.
The third and the last parasitic plant! And I am so excited to have found it! This is an “in the field shot” and it is tiny. So sorry for the poor shot. Do you remember in the Quick Jaunt post I was looking for a plant? Well, I found it on this drive about-tour!
The studio shot!!! The Pilostyles thurberi is only found on Black Dalea (Dalea frutescens) in North Texas. In case you can’t tell, it is the little red and brown snubs on the woody stem of the Black Dalea. Those are its flowers!
A close up the tiny flowers which measured only 3.5mm high! This plant is an endoparasitic plant. It lives in the stems of the Black Dalea. It seems it can also be found in Indigobush (Dalea formosa) where it occurs in Texas according to the FNCT. In addition, out west it can grow in the shrubs of the Psorothamnus, especially Dyeweed (Psorothamnus emoryi). Sources: https://www2.palomar.edu/users/warmstrong/ploct98.htm and The Jenson Manual of Vascular Plants of California).
Sticky seeds inside the female flower!
A close look at the tiny seeds. Wayne Armstrong’s best hypothesis for seed dispersal (and possibly some pollination) is ants. Update: See Jeanne’s comments below for on articles links she found on the subject. Very interesting! Thanks Jeanne!
Different strategies make for a very interesting world. And now that I have found Pilostyles in Montague County, my next goal is to find it on the grasslands!
looked up pilostyles – enjoyed these articles (am sure you already saw these) – good drawings and photos. Raspberry scent! And the name – Thurber’s stemsucker.
Thanks Jeanne! I had not seen the second article/study. Most enlightening! I think I read the first one, but was certainly worth a second read. Both great information, thanks for sharing!
Ants make sense since a lot of legumes lure them in with sugar, yes? This is so cool.
Really is! 😎
Fantastic! I’ll be looking for this from now on!
👍🏼
looked up pilostyles – enjoyed these articles (am sure you already saw these) – good drawings and photos. Raspberry scent! And the name – Thurber’s stemsucker.
https://art-botanical.org/DesertBreeze/052019-parasitic-pilostyles-thurberi.html
https://www.pollinationecology.org/index.php/jpe/article/view/267/79
Thanks Jeanne! I had not seen the second article/study. Most enlightening! I think I read the first one, but was certainly worth a second read. Both great information, thanks for sharing!