''Lygodium'' (climbing fern) is a genus of about 40 species of

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

s, native to tropical regions across the world, with a few temperate species in eastern

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and eastern

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. It is the sole genus in the family Lygodiaceae in the

Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ...

classification of 2016 (PPG I). Alternatively, the genus may be placed as the only genus in the subfamily Lygodioideae of a more broadly defined family Schizaeaceae, the family placement used in ''

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

'' . Per recent molecular evidence, Lygodiaceae is thought to have diverged relatively early from the other members of the Schizaeales due to the relatively high level of synonymous sequence divergence between the families within the Schizaeales.

Description

''Lygodium'' are unusual in that the rachis, or midrib, of the

frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...

is thin, flexible, and long, the frond unrolling with indeterminate growth and the rachis twining around supports, so that each frond forms a distinct

vine A vine is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas, or runners. The word ''vine'' can also refer to such stems or runners themselves, for instance, when used in wicker work.Jackson; Benjamin; Da ...

. The fronds may be from long, depending on the species. They are also easily identifiable by their possession of apical buds that lay dormant until damage to the rachis occurs, allowing them a high degree of endurance.

Range

''Lygodium'' is a wide ranging genus with native populations existing in Asia, Australasia, Africa, and North and South America. The genus is largely pan-tropical, with the center of diversity being Pacific islands, such as Borneo, the Philippine islands, and New Guinea. There do exist several species tolerant of temperate climates such as ''

Lygodium palmatum ''Lygodium palmatum'' is the only species of its genus native to North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by th ...

'', which is endemic to the Appalachian region of eastern North America, and ''

Lygodium japonicum ''Lygodium japonicum'' is a species of fern that is known by the common names vine-like fern and Japanese climbing fern. It is native to eastern Asia, including Taiwan, Japan, Korea, southeastern Asia, and India, and eastern Australia. The fern i ...

'', which is native to Japan, but highly invasive in the Southeastern United States. For more on this, refer to the "As invasive species" section below. The lack of extant ''Lygodium'' species in Europe is commonly attributed to the

Pleistocene glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago) and is ongoing. Although geologists describe ...

wiping them out. Similar extirpations did not occur in other high middle and high latitude areas, such as the United States and Japan that do have ''Lygodium'' populations at present. This discrepancy is thought to be due to the East-West orientation of the European Alps preventing southward migration of ''Lygodium'' members, among other extirpated species, while the relatively North-South orientations of the

Appalachian mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

and

Japanese Alps The is a series of mountain ranges in Japan which bisect the main island of Honshu. The peaks that tower over central Honshu have long been the object of veneration and pilgrimage. These mountains had long been exploited by local people for raw m ...

allowed such southward migration.

Uses

''Lygodium'' species, known as ''nito'', are used as a source of fibers in the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

. The fibers are used as material for weaving, most notably of traditional

salakot Salakot is a traditional lightweight headgear from the Philippines commonly used for protection against the sun and rain. Variants occur among ethnic groups, but all are shaped like a dome or cone and can range in size from having very wide br ...

headgear.

As invasive species

Some ''Lygodium'' species are now considered very problematic invasive weeds in the southeastern United States. Populations of ''Lygodium'' have increased more than 12-fold over the past decade, as noted by Florida's

Institute of Food and Agricultural Sciences An institute is an organizational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics, or can also be a professional body. In some countries, institutes ca ...

. Japanese climbing fern (''

'') was added to the Florida Noxious Weed List in 1999. It is also a major problem in pine plantations, causing contamination and harvesting problems for the pine straw industry. Old World climbing fern (''

Lygodium microphyllum ''Lygodium microphyllum'' (commonly known as, variously, climbing maidenhair fern, Old World climbing fern, small-leaf climbing fern, or snake fern) is a climbing fern originating in tropical Africa, Southeast Asia, Melanesia and Australia. It is ...

'') infests cypress swamps and other hydric sites, forming a monoculture. This massive infestation displaces all native flora and fauna, completely changing the ecosystem of the area. Plants in this genus have basal chromosome counts of ''n=28, 29, 30''.

Phylogeny

References

External links

Flora of North America: ''Lygodium''
* *C.Michael Hogan. 2010
''Fern''. Encyclopedia of Earth. eds. Saikat Basu and C.Cleveland. National Council for Science and the Environment
Washington DC.
Flora of China: ''Lygodium'' species list
{{Authority control Fern genera Taxa named by Olof Swartz