Plantago

Plantago is a genus of about 200 species of small, inconspicuous plants commonly called plantains. They share this name with the very dissimilar plantain, a kind of banana. Most are herbaceous plants, though a few are subshrubs growing to 60 cm (23.5 in) tall. The leaves are sessile, but have a narrow part near the stem which is a pseudo-petiole. They have three or five parallel veins that diverge in the wider part of the leaf. Leaves are broad or narrow, depending on the species. The inflorescences are borne on stalks typically 5-40 cm (2.25-15.75 in) tall, and can be a short cone or a long spike, with numerous tiny wind-pollinated flowers.

Plantains are used as food plants by the larvae of some species of Lepidoptera - see list of Lepidoptera that feed on plantains.

They are found all over the world, including America, Asia, Australia, New Zealand, Africa and Europe. Many species in the genus are cosmopolitan weeds.

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Uses

Plantago species are often used as herbal remedies. The herb is astringent, anti-toxic, antimicrobial, anti-inflammatory, as well as demulcent, expectorant, styptic and diuretic. Externally, a poultice of the leaves is useful for insect bites, poison-ivy rashes, minor sores, and boils. In folklore it is even claimed to be able to cure snakebite. Internally, it is used for coughs and bronchitis, as a tea, tincture, or syrup. The broad-leaved varieties are sometimes used as a leaf vegetable for salads, green sauce, et cetera.

Plantain seed husks expand and become mucilaginous when wet, especially those of P. psyllium, which is used in common over-the-counter bulk laxative and fiber supplement products such as Metamucil. P. psyllium seed is useful for constipation, irritable bowel syndrome, dietary fiber supplementation, and diverticular disease. Recent research is also showing it to be promising in lowering cholesterol and controlling diabetes.

Psyllium supplements are typically used in powder form, along with adequate amounts of fluids. A dose of at least 7 grams daily taken with adequate amounts of fluid (water, juice) is used by some for management of elevated cholesterol. There are a number of psyllium products used for constipation. The usual dose is about 3.5 grams twice a day. Psyllium is also a component of several ready-to-eat cereals.

In India, mucilage from (Plantago ovata) is obtained by grinding off the husk. The mucilage is sold as Isabgol, a laxative which is used to control irregular bowel syndrome and constipation. It is also used in cereals as a treatment of mild to moderate hypercholesterolemia and for reducing blood glucose. It has been used as an indigenous Ayurvedic and Unani medicine for a whole range of bowel problems including chronic constipation, amoebic dysentry and diarrhoea.

In Romania and Bulgaria, leaves from Plantago major are used as a folk remedy to preventing infection on cuts and scratches because of its antiseptic properties.

Species

There are about 200 species of Plantago, including:

Gallery

References

Cho, Y.; Mower, J. P., Qiu, Y.-L. & Palmer, J. D. (2004). Mitochondrial substitution rates are extraodinarily elevated and variable in a genus of flowering plants. Proceedings of the National Academy of Science 101: 17741-17746

Dagar, J. C.; Kumar, Y. & Tomar, O. S. (2006). Cultivation of medicinal isabgol (Plantago ovata) in alkali soils in semiarid regions of northern India. Land Degradation and Development 17: 275-283

Rahn, K. (1996). A phylogenetic study of the Plantaginaceae. Botanical Journal of the Linnean Society 120: 145-198

Rønsted, N.; Chase, M. W.; Albach, D. C. & Bello, M. A. (2002). Phylogenetic relationships within Plantago (Plantaginaceae): evidence from nuclear ribosomal ITS and plastid TrnL-F sequence data. Botanical Journal of the Linnean Society 139: 323-338