Friday Fellow: Mexican Giant Horsetail

by Piter Kehoma Boll

If you are walking through the forest of Central America, you may end up finding something that at first you could think is a group of bamboos, plants growing as a cylindrical segmented stem that can reach up to 7 m in height, as seen in the picture below:

A group of bamboos? Not exactly. Photo by Alex LomasAlex Lomas.*

Those are not actually bamboos, though, but specimens of the largest species of horsetail that exists today, the Mexican giant horsetail, Equisetum myriochaetum. It can be found growing naturally from Peru to Mexico in areas of fertile soil, especially along water bodies such as streams and swamps.

As other horsetails, the Mexican giant horsetail has an erect and hollow stem with very narrow leaves growing in a whirl around the “joints” of the stem. The leaves are very simple, similar to those of more primitive plants such as the spikemosses and ground pines, but are thought to be a simplification of more complex leaves, as they are more closely related to the complex-leaved ferns.

More than only the largest horsetail in the world, the Mexican giant horsetail is an important medicinal plant in Mexican folk medicine, being used to treat kidney diseases and type 2 diabetes mellitus. And as in many other occasions, laboratory studies confirmed that water extracts from the aerial parts of E. myriochaetum do indeed reduce the blood glucose levels of type 2 diabetic patients without reducing their insulin levels. One more point to traditional medicine.

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References:

EOL – Encyclopedia of Life. Equisetum myriochaetum. Available at <http://eol.org/pages/6069616/overview&gt;. Access on March 4, 2017.

Revilla, M., Andrade-Cetto, A., Islas, S., & Wiedenfeld, H. (2002). Hypoglycemic effect of Equisetum myriochaetum aerial parts on type 2 diabetic patients Journal of Ethnopharmacology, 81 (1), 117-120 DOI: 10.1016/S0378-8741(02)00053-3

Royal Botanic Garden Edinburgh. Equisetum myriochaetum. Available at <http://www.rbge.org.uk/the-gardens/plant-of-the-month/plant-profiles/equisetum-myriochaetum&gt;. Access on March 4, 2017.

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Friday Fellow: Beggar’s tick

by Piter Kehoma Boll

What if the cure for cancer has been living in your garden all this time and you have been trying to get rid of it because it is an annoying weed?

I cannot assure you that the answer lies in today’s Friday Fellow, but it certainly has a good potential. Its name is Bidens pilosa, commonly known as beggar’s tick, beggar ticks, black jack, cobbler’s pegs or Spanish needle.

Not extravagant, but discrete. This is Bidens pilosa. Photo by Wibowo Djatmiko.*

Native from the Americas, where it grows in open fields and forest glades, the beggar’s tick is now found worldwide, from Eurasia and Africa to Australia and the Pacific Islands. At first it does not call much attention while growing among other weeds. It grows up to 1.8 m tall and has small discrete flowers in a daisy-like head, with a handful of white ray florets and a small disc of yellow florets.

The problem with this fellow happens when you have to pass among them after the flowers have turned into fruits.

The terrible evil infructescence of the beggar’s tick. Photo by Wibowo Djatmiko.*

The fruits of the beggar’s tick are small, stiff, dry rods with about 2–4 small heavily barbed awns at the end. They are arranged in spherical infructescences are are eager to stick on any passing animal. The small barbed awns catch onto fur and clothes and the fruits are easily dispersed to other areas. It is a classical example of zoochory, i.e., seed dispersal by animals. If you live in an area where this plant is common, you most likely have had the experience of finding your clothes full of those prickling seeds, especially after playing, working or simply walking through a field.

But the beggar’s tick is much more than a dull and annoying weed. In Subsaharan Africa, it is one of the most widely eaten plants. Its leaves are edible when cooked, but have a strong and unpleasant taste.

Furthermore, the beggar’s tick is used in traditional medicine in South America and several studies have found out that it is indeed a powerful medicine. Extracts from the plant have shown several medicinal properties, including:

• Antibacterial and antifungal activity
• Antimalarial activity
• Anti-herpes simplex activity
• Ability to reduce tumoral and leukemic cells
• Immunosuppressive and anti-inflammatory effects

If this were not enough, the beggar’s tick has the ability to bioacumulate cadmium in its tissues, so that it can be used to depollute cadmium-contaminated soils.

The next time you find your clothes full of beggar’s ticks, remember that it is more, much more, than simply an annoying weed.

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References:

Brandão, M., Krettli, A., Soares, L., Nery, C., & Marinuzzi, H. (1997). Antimalarial activity of extracts and fractions from Bidens pilosa and other Bidens species (Asteraceae) correlated with the presence of acetylene and flavonoid compounds Journal of Ethnopharmacology, 57 (2), 131-138 DOI: 10.1016/S0378-8741(97)00060-3

Chang, J., Chiang, L., Chen, C., Liu, L., Wang, K., & Lin, C. (2001). Antileukemic Activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb. The American Journal of Chinese Medicine, 29 (02), 303-312 DOI: 10.1142/S0192415X01000320

Chiang, L., Chang, J., Chen, C., Ng, L., & Lin, C. (2003). Anti-Herpes Simplex Virus Activity of Bidens pilosa and Houttuynia cordata The American Journal of Chinese Medicine, 31 (03), 355-362 DOI: 10.1142/S0192415X03001090

Deba, F., Xuan, T., Yasuda, M., & Tawata, S. (2008). Chemical composition and antioxidant, antibacterial and antifungal activities of the essential oils from Bidens pilosa Linn. var. Radiata Food Control, 19 (4), 346-352 DOI: 10.1016/j.foodcont.2007.04.011

Kviecinski, M., Felipe, K., Schoenfelder, T., de Lemos Wiese, L., Rossi, M., Gonçalez, E., Felicio, J., Filho, D., & Pedrosa, R. (2008). Study of the antitumor potential of Bidens pilosa (Asteraceae) used in Brazilian folk medicine Journal of Ethnopharmacology, 117 (1), 69-75 DOI: 10.1016/j.jep.2008.01.017

Oliveira, F., Andrade-Neto, V., Krettli, A., & Brandão, M. (2004). New evidences of antimalarial activity of Bidens pilosa roots extract correlated with polyacetylene and flavonoids Journal of Ethnopharmacology, 93 (1), 39-42 DOI: 10.1016/j.jep.2004.03.026

Pereira, R., Ibrahim, T., Lucchetti, L., da Silva, A., & de Moraes, V. (1999). Immunosuppressive and anti-inflammatory effects of methanolic extract and the polyacetylene isolated from Bidens pilosa L. Immunopharmacology, 43 (1), 31-37 DOI: 10.1016/S0162-3109(99)00039-9

Sun, Y., Zhou, Q., Wang, L., & Liu, W. (2009). Cadmium tolerance and accumulation characteristics of Bidens pilosa L. as a potential Cd-hyperaccumulator Journal of Hazardous Materials, 161 (2-3), 808-814 DOI: 10.1016/j.jhazmat.2008.04.030

Wikipedia. Bidens pilosa. Available at < https://en.wikipedia.org/wiki/Bidens_pilosa >. Access on July 31, 2016.

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