Phlebodium aureum

Phlebodium aureum
A large stand of P. aureum.
Conservation status

Secure (NatureServe)
Scientific classification
Kingdom: Plantae
Division: Pteridophyta
Phylum: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Polypodiaceae
Genus: Phlebodium
Species: P. aureum
Binomial name
Phlebodium aureum
(L.) J.Sm.

Phlebodium aureum (Golden polypody, Golden serpent fern or Cabbage palm fern; syns Polypodium aureum, Polypodium leucatomos - commonly, but incorrectly, cited as Polypodium leucotomos) is an epiphytic fern native to tropical and subtropical regions of the Americas. It is confined to the eastern side of the continents, extending north into the United States to Florida and the extreme southeast of Georgia, and south through the Caribbean (the Bahamas, Puerto Rico, and Lesser Antilles), and northern and eastern South America to Paraguay. It is the only species of Phlebodium found in North America, the other ten or so species all confined to South America. Other common names include Calaguala (among Spanish speaking peoples), Kalawalla, Samambia[1], and Anapsos.

It is a rhizomatous fern, with the creeping rhizome 8-15 mm (rarely 30 mm) in diameter, densely covered in the golden-brown scales that give the species its name. The fronds are large and pinnatifid (deeply lobed), from 30-130 cm long and 10-50 cm broad, with up to 35 pinnae; they vary in color from bright green to glaucous green and have undulate margins. Several round sori run along each side of the pinna midrib, and the minute spores are wind-dispersed. The fronds are evergreen in areas with year-round rainfall, semi-evergreen or briefly deciduous in areas with a marked dry season.

Habitat

This fern is rarely terrestrial in habitat, usually colonizing the canopies of tropical rainforests and the dwarf palms of subtropical forests. It is common in the cloud forests of the Caribbean and northern South America. It grows in varied habitats in Florida, including swamps and hammocks, and can thus apparently tolerate a wide range of microclimates. Its restriction to the tropics and subtropics is readily explained by its intolerance of anything other than very brief, light frosts. High levels of light are also critical for growth of this species, and its deciduous habit allows it to invade relatively dry areas.

Cultivation and uses

Phlebodium aureum is well-adapted to cultivation and is valued both as an ornamental plant and in herbal medicine.

It can be cultivated in greenhouses in nontropical climates if night temperatures do not fall below about 5 °C. Several cultivars have been selected for garden planting, with varying leaf color from grey-green to silver-green to blue-green, or with cristate or very wavy frond margins.

Decoctions have been used as a panacea in Central American folk medicine. These tonics were prescribed for a multitude of ailments, ranging from asthma to heart disease. A close relative, Polypodium vulgare, was used historically in Europe up to the Renaissance to relieve coughing and treat mental illness. Its use as a tea for blood cleansing began with the Mayans, and continues today in Honduran culture.

It has been shown to be effective when administered orally as an immunomodulator (selectively modulates overactive immune cells), antipsoriatic, neuroprotective (protects brain cells), cough suppressant, anti-inflammatory, and ultraviolet light protectant.[2] [3] [4] [5] It has been commercially available since 1982 in Europe, and as yet has had no toxicity reports, although it may enhance the effects of digoxin and/or other digoxin-type prescription heart drugs.

Its uses include:

It is also reported to have been an aid for those with Multiple Sclerosis and Vitiligo.

A common registered brand includes Heliocare based in Spain. Additionally US patents have been granted for various processes for producing extracts.

References

  1. ^ Taylor, Leslie Granville (2005). The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals. Garden City Park, NY: Square One Publishers. ISBN 0-7570-0144-0. 
  2. ^ Gonzalez S, Alonso-Lebrero JL, Del Rio R, Jaen P (July 2007). "Polypodium leucotomos extract: a nutraceutical with photoprotective properties". Drugs Today 43 (7): 475–85. doi:10.1358/dot.2007.43.7.1062667. PMID 17728848. 
  3. ^ Middelkamp-Hup MA, Pathak MA, Parrado C, et al. (December 2004). "Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin". J. Am. Acad. Dermatol. 51 (6): 910–8. doi:10.1016/j.jaad.2004.06.027. PMID 15583582. 
  4. ^ Siscovick JR, Zapolanski T, Magro C, et al. (June 2008). "Polypodium leucotomos inhibits ultraviolet B radiation-induced immunosuppression". Photodermatol Photoimmunol Photomed 24 (3): 134–41. doi:10.1111/j.1600-0781.2008.00352.x. PMID 18477132. 
  5. ^ Mulero M, Rodríguez-Yanes E, Nogués MR, et al. (August 2008). "Polypodium leucotomos extract inhibits glutathione oxidation and prevents Langerhans cell depletion induced by UVB/UVA radiation in a hairless rat model". Exp. Dermatol. 17 (8): 653–8. doi:10.1111/j.1600-0625.2007.00684.x. PMID 18312382.