Lalang+(Imperata+cylindrica+(L.)+P.+Beauv.)

toc Lalang (//Imperata cylindrica//) is one of the most common grasses in Singapore and Southeast Asia. It ranks among the world’s top most invasive species. Lalang is native to Southeast Asia, Philippines, China, and Japan, but has spread to every continent other than Antarctica. Lalang is closely related to many agriculturally important plants such as sugarcane and rice, but is ironically a significant pest weed in agriculture because of its ability to spread quickly and aggressively outgrow other plants in the area, taking over valuable cropland. In its native regions, it forms extensive grassland that supports native wildlife and has many human uses, particularly in traditional medicine.
 * = [[image:Lalang field.jpg width="640" height="480" align="center"]] ||
 * = Field of lalang //Imperata cylindrica.// (Image Credit: JMK) ||

 Here's an introductory video about this invasive plant: media type="youtube" key="g_3gs8c4hqg" width="560" height="315" align="center"

=Common Names = Lalang is known by a variety of common names:

 Lalang – most common in Singapore and Malaysia  Cogon grass – Philippines and the United States  Alang-alang – Indonesia

 Other names include Blady grass, Speargrass, Japanese bloodgrass, kunai grass, cotton-wool grass, and more.

=Ecology =
 * = [[image:World distribution map lalang.jpg width="608" height="321" align="center"]] ||
 * = Map of countries where //Imperata cylindrica// is native (green) and considered invasive (blue). Information obtained from Global Invasive Species Database. ||

Habitat
Lalang can be found in warm areas with an annual rainfall of 75–200cm and in a large variety of habitats, from deserts and sandy shores to swamps, through a wide range of soil types . It is particularly prolific in areas affected by human use .

 Lalang is reported to occupy over 500 million hectares worldwide. In its native tropical Asia, it forms large swathes of natural grassland that occupy an estimated 35 million hectares, with the biggest areas in Indonesia and India. Lalang occupies about one-fifth of the total land area in Sri Lanka and the Philippines. The amount of grassland in Asia is gradually increasing due to land clearing by wildfires, but is at the same time being cleared for permanent plantations and urban uses.

As an Ecosystem
<span style="font-family: Arial,Helvetica,sans-serif;">Lalang grasslands can be part of the natural plant succession from barren ground to forest, but can also remain in this stage for hundreds of years. In Singapore, abandoned plantations from the early part of 20th century were taken over by lalang grassland, which has in turn grown into early secondary forest mostly made of the tree //Adinandra belukar//.

<span style="font-family: Arial,Helvetica,sans-serif;"> In Nepal, these grasslands form an important part of the ecosystem, supporting endangered species such as the tiger //Panthera tigris, greater one-horned rhinoceros Rhinoceros unicornis//, the hispid hare //Caprolagus hispidus// and Bengal florican //Eupodotis bengalensis//.

<span style="font-family: Georgia,serif;">Lalang and Fire
<span style="font-family: Arial,Helvetica,sans-serif;">These grasslands are extremely susceptible to fires, burning readily even when still green and not dry. Fire is an important part of their ecology as burning enhances the growth of new shoots and triggers flowering and seed production. This plant may sacrifice some leaves to maintain a healthy amount of rhizomes for survival, and these leaves can serve as fuel for fires. These leaves burn intensely and kills off almost all other vegetation. The rhizomes are protected from fires as they are buried deep in the soil, ready to sprout when the land above is cleared. This video shows how well a lalang field can burn. media type="youtube" key="uAMlrDyllSg" width="560" height="315" align="center"

<span style="font-family: Georgia,serif;">Interaction with other plants
<span style="font-family: Arial,Helvetica,sans-serif;">Lalang is known to be a vicious competitor with other plants. It directly competes for nutrients, light, water, and space, and also produces substances that stop surrounding plants from growing. The rhizomes can even physically pierce through the roots of surrounding plants and cause fungal infections. This makes it highly detrimental when it invades agricultural crops.

=<span style="font-family: Georgia,serif;">Invasiveness = <span style="font-family: Arial,Helvetica,sans-serif;">Lalang is listed as among the world’s top 100 most invasive species by the IUCN and is listed as a pest weed in 73 countries. Lalang spreads fast and is difficult to eradicate because its seeds are airborne and can spread widely. It can also spread without seeds using underground stems called rhizomes, which grow rapidly, and are difficult to completely eradicate. In the United States, it was first accidentally introduced as packing material. Later, it was deliberately introduced as forage and for soil stabilization and started spreading rapidly along roadways.

<span style="font-family: Arial,Helvetica,sans-serif;"> Because of its high competitiveness, lalang poses a huge problem to agriculture, particularly in Africa and the United States. Among the species it affects are maize, coconut, rice, oil palm, cassava, yams, teak, cocoa, kola, coffee cashew, and rubber, especially in the stage before the crops mature. Lalang reduces crop yield or even kills the plants entirely. Because it burns easily, it also increases the risk of fire which can destroy vast amounts of farmland and reduces the viability of the soil.

<span style="font-family: Georgia,serif;">In Singapore
<span style="font-family: Arial,Helvetica,sans-serif;">It is uncertain whether it is a native or introduced species in Singapore. It does not appear to pose a large problem in Singapore, as it primarily grows in urban areas rather than the forested areas where most of Singapore’s rare and native biodiversity are found. Lalang is not a shade-tolerant plant and does not grow well in forest. So far, there are no documented harmful effects of lalang in Singapore.
 * = [[image:Lalang Grass near UTown.jpg width="648" height="364" align="center"]] ||
 * = //Imperata cylindrica// growing in Singapore along Clementi Road near University Town. (Photo credit: Amanda Lim) ||

=<span style="font-family: Georgia,serif;">Management = <span style="font-family: Arial,Helvetica,sans-serif;">Many methods of managing lalang in agricultural areas are used worldwide, and often varies by what the farm can afford. A combination of several of the different types of methods below are usually used.

<span style="font-family: Georgia,serif;">Chemical Management
<span style="font-family: Arial,Helvetica,sans-serif;">Herbicides are most often used to control the spread of invasive lalang, particularly on large farms. Sodium arsenite was one of the first chemicals used to control lalang, but was inefficient and highly toxic. Later, glycophosate and imazapyr became more commonly used, particularly as they are both more efficient and are non-toxic to animal wildlife. Many studies are being conducted on finding more efficient and targeted herbicide additives that can be used in conjunction with these two chemicals.

<span style="font-family: Georgia,serif;">Mechanical Management
<span style="font-family: Arial,Helvetica,sans-serif;">Lalang is managed on many farms simply by mowing or burning. However, without removing the underground rhizomes, lalang cannot be effectively controlled and burning can even encourage regrowth. Small scale farms tended to manually cut the rhizomes up, then either left them on the surface to dry out or buried deep in the ground to make the rhizomes unable to regrow new stems. However, it is difficult to completely eradicate all the rhizomes and is only useful in the short term. An alternative method is ‘pressing’, whereby leaves are pressed down and bent without breaking the blades to suppress growth while avoiding the growth of new shoots.

<span style="font-family: Georgia,serif;">Cultural Management
<span style="font-family: Arial,Helvetica,sans-serif;">Growing other plants that create shade over lalang is another method employed to control its growth. Plants in the bean family (legumes) are often used, such as //Stylosanthes guianensis// and velvet bean //Mucuna pruriens//. Like lalang, S. guianensis// produces chemicals that suppress the growth of surrounding plants, combating lalang growth, but can be more easily removed afterwards by crops that provide shade or by grazing animals. <span style="font-family: Arial,Helvetica,sans-serif;"> Addtionally, these plants can grow on less fertile land and enrich the soil for future crops at the same time. (Image Credit: Tropical Seeds) ||= Seed pod of velvet bean //Mucuna puriens.// (Image Credit: Shoba R) ||
 * = [[image:taxo4254/stylo (tropical seeds).jpg width="470" height="315" link="@https://www.flickr.com/photos/96332760@N06/8857224742/in/set-72157633741775019/"]] ||= [[image:Mucuna-pruriens-fruit.jpg width="244" height="324" link="@https://en.wikipedia.org/wiki/Mucuna_pruriens#/media/File:Mucuna-pruriens-fruit.jpg"]] ||
 * = //Stylosanthes guianensis//, a plant commonly used to suppress //Imperata cylindrica//.

=<span style="font-family: Arial,Helvetica,sans-serif;">Human Uses = <span style="font-family: Arial,Helvetica,sans-serif;"> Despite all its negative impacts as an invasive species, lalang also has a lot of uses! Some varieties are cultivated as an ornamental plant in the US. Singapore also uses them as ornamental plants in parks, and to stabilize slopes. It was commonly used in the United States to stabilize slopes and reduce soil erosion, but its invasiveness led it to be banned in the state of Florida. <span style="font-family: Arial,Helvetica,sans-serif;">In Chinese medicine, the dried rhizome is used to treat bleeding ailments such as nosebleeds, the coughing of blood, and hemorrhages, as well as high fevers and heatstroke. It is also used as a diuretic and prepared as a cooling tea in the summer. In the Philippines, it is used to treat dysentery, while in Malaysia, it is used for diarrhoea and rheumatism.
 * = [[image:taxo4254/Ornamental lalang at Arts canteen.jpg width="640" height="360"]] ||
 * = An ornamental variant of //Imperata cylindrica// in the National University of Singapore. (Photo Credit: Amanda Lim) ||

<span style="font-family: Arial,Helvetica,sans-serif;"> Dried lalang leaves are also used to thatch roofs in Southeast Asia, as animal fodder, and even to make paper. Paper making is only done on a small scale however, as the difficulty in handling means that it is more efficient to use lalang grassland to grow trees instead. Below is a video about how lalang is used to make paper in the Philippines:

media type="youtube" key="Bzlmd7cB6gI" width="560" height="315" align="center"

=<span style="font-family: Georgia,serif;">How to Identify Lalang =

<span style="font-family: Georgia,serif;">Leaves
<span style="font-family: Arial,Helvetica,sans-serif;">Lalang leaf blades are long and slender, growing about 150cm long or more and about 4-10mm wide. They have rough, finely sawtoothed edges and a mid-vein that runs slightly-off center down the length of the leaf. The leaves contain substances (silicates) which make them tough and unpalatable to herbivores <span style="font-family: Arial,Helvetica,sans-serif;"> <span style="font-family: Arial,Helvetica,sans-serif;">. Lalang stores carbon that is used for photosynthesis using a method that makes it more efficient at photosynthesis (the C4 pathway) and grow better in sun than under shade.


 * = [[image:Off-center mid-vein lalang leaf.jpg width="640" height="216"]] ||
 * = Section of //Imperata cylindrica// leaf. Note particularly the off-center mid-vein. (Photo credit: Amanda Lim) ||

<span style="font-family: Georgia,serif;">Flowers
<span style="font-family: Arial,Helvetica,sans-serif;">Flowering does not happen often, usually only as a response to periods of stress such as burning, cutting or drought. The flowers form an inflorescence (a collection of tiny, reduced flowers). Each inflorescence can be found at the end of a long stalk. They are cylindrical, about 3-20cm long, 0.5-2.5cm in diameter, and covered with white hairs. Each flower has two anthers (the part of the flower that produces pollen), which distinguishes it from other members of its genus. The colours of the flowers themselves can vary from pinkish red in ornamental variants, to beige, to white.
 * = [[image:Imperata cylindrica plate 5 de Beauvais.jpg width="264" height="471"]] ||= [[image:Lalang flower inflorescence.jpg width="320" height="477"]] ||
 * = Plate featuring the flowers and seeds of //Imperata cylindrica//. (Source: de Beauvais (1812) //Essai d'une Nouvelle Agrostographie.//) ||= Inflorescence of an ornamental variant of //Imperata cylindrica//. Note the two anthers. (Photo credit: Amanda Lim) ||

<span style="font-family: Georgia,serif;">Rhizomes and Seeds
<span style="font-family: Arial,Helvetica,sans-serif;">Like many other grasses, lalang can reproduce both asexually and sexually. Asexual reproduction is through an underground stem, known as a rhizome. A single rhizome can produce many stems and new clonal rhizomes. These rhizomes are white, scaly, and branching, and are about 2–4.5mm in diameter. About 50% of them can be found in the top 20cm of the soil, but can sometimes reach a meter deep. Lalang can also disperse through seeds, which are small and airborne, attached to long white hairs <span style="font-family: Arial,Helvetica,sans-serif;">. A single plant can produce up to 3000 seeds. Whether rhizomes or seeds are the primary mode of reproduction for lalang appears to be uncertain.


 * = [[image:Lalang Seeds.jpg width="236" height="385"]] ||= [[image:Rhizomes roots and seeds lalang.jpg width="516" height="387" link="@https://commons.wikimedia.org/wiki/Category:Imperata_cylindrica#mediaviewer/File:Imperata_cylindrica_2308122.png"]] ||
 * = Close look at the seeds of //Imperata cylindrica//. (Photo credit: Amanda Lim) ||= // Imperata cylindrica // rhizomes, roots, and seeds. (Image Credit: L. M. Marsh, Florida Department of Agriculture and Consumer Services, Bugwood.org ) ||

=<span style="font-family: Georgia,serif;">Taxonomy =

<span style="font-family: Georgia,serif;">Nomenclature
<span style="font-family: Arial,Helvetica,sans-serif;">The basionym of //Imperata cylindrica// is //Lagurus cylindricus//, very briefly listed by Linnaeus in //Systema Naturae//. The currently accepted name is //Imperata cylindrica// (L.) P. Beauv, described by Palisot de Beauvois in 1812. It is often also found as //Imperata cylindrica// (L.) Raeusch, as this name was only invalidated recently due to a lack of a reference to the basionym in a section of the description. A long list of synonyms can be found at the [|World Checklist of Selected Plant Families]. <span style="font-family: Arial,Helvetica,sans-serif;"><span style="font-family: Arial,Helvetica,sans-serif;">There are five main recognized varieties of //I. cylindrica//, namely //I. cylindrica var. major, africana, europa, condensata,// and //latifolia,// These are distinguished from each other by chromosome number <span style="font-family: Arial,Helvetica,sans-serif;">. These varieties show high genetic variation not only between each other but also within a single variety, allowing //I. cylindrica// to grow in a large range of conditions. Despite the genetic variation, they still readily interbreed with each other, and are thus not considered separate species.
 * = [[image:Systema Naturae.jpg width="937" height="169"]] ||
 * = Original entry of //Imperata cylindrica// as //Lagurus cylindricus// in //Systema Naturae.// (Source: Linnaeus (1759) //Systema Naturae.//) ||

<span style="font-family: Georgia,serif;">Taxonavigation
<span style="font-family: Arial,Helvetica,sans-serif;"> Kingdom: Plantae <span style="font-family: Arial,Helvetica,sans-serif;"> Phylum: Magnoliophyta <span style="font-family: Arial,Helvetica,sans-serif;"> Class: Equisetopsida <span style="font-family: Arial,Helvetica,sans-serif;"> Subclass: Magnoliidae <span style="font-family: Arial,Helvetica,sans-serif;"> Superorder: Lilianae <span style="font-family: Arial,Helvetica,sans-serif;"> Order: Poales <span style="font-family: Arial,Helvetica,sans-serif;"> Family: Poaceae <span style="font-family: Arial,Helvetica,sans-serif;"> (Subfamily: Panicoideae) <span style="font-family: Arial,Helvetica,sans-serif;"> (Supertribe: Andropogonodae) <span style="font-family: Arial,Helvetica,sans-serif;"> (Tribe: Andropogoneae) <span style="font-family: Arial,Helvetica,sans-serif;"> Genus: //Imperata//

<span style="font-family: Arial,Helvetica,sans-serif;"> Unbracketed rank names were obtained from Tropicos (24), and bracketed rank names obtained from the classification of the Poaceae by Soreng et al..

<span style="font-family: Arial,Helvetica,sans-serif;"> The exact relationship of the genus //Imperata// to its sister taxa is unknown, classified as //incertae sedis// (latin meaning ‘of uncertain taxonomic position’ ) within the tribe Andropogoneae by Soreng et al..

<span style="font-family: Georgia,serif;">Phylogenetic Analyses
<span style="font-family: Arial,Helvetica,sans-serif;">The two phylogenetic trees shown below were generated by Hodkinson et al. (2002) (left) and Burke et al. (2016) (right) and show little consensus with each other. Hodkinson et al. used nuclear ribosomal DNA and chloroplast introns to create a maximum parsimony tree. The more recent tree generated by Burke et al. used complete chloroplast genomes and combined the results from maximum parsimony, maximum likelihood, and Bayesian analytical methods. The majority of the branches on the tree by Burke et al. have extremely strong support with all three analytical methods, and uses a large amount of genetic data, suggesting that it is a very robust representation of the relationships between the species featured in the trees.

<span style="font-family: Arial,Helvetica,sans-serif;"> In both trees, //Imperata cylindrica// is highlighted in red. A few important plant species representing genera common to both trees are also highlighted for comparison between the trees and with //Imperata cylindrica//. <span style="font-family: Georgia,serif; font-size: 14pt;"> **Image and Video Credits**
 * = [[image:2002 tree.jpg width="397" height="520"]] ||= [[image:taxo4254/2016 tree.jpg width="382" height="512"]] ||
 * = Phylogenetic tree adapted from Hodkinson et al (2002), using ITS nuclear ribosomal DNA and trnL-F intron and spacer regions of plastid (chloroplast) DNA. One of 32,039 equally most parsimonious trees. Numbers above branches indicate steps, while numbers below branches indicate bootstrap percentages above 50%. Solid lines indicate groups found in all shortest trees, dotted lines indicate those which are not. (Used with permission from the author) ||= Phylogenetic tree adapted from Burke et al (2016), generated using complete chloroplast genomes. All tree branches have bootstrap value of 100 and posterior probabilities of 1.0 except where indicated (Maximum Likelihood | Maximum Parsimony | Bayesian posterior probability). ||
 * = Highlighted species: Red – //Imperata cylindrica//. Yellow – //Zea diploperennis//, maize //Zea mays//. Blue – sugarcane //Saccharum officinarum//. Purple – //Sorghum halepense, Sorghum timorense//, Sorghum //Sorghum bicolor//. ||
 * 1) Field of lalang //Imperata cylindrica//. Image uploaded by JMK, on Wikimedia Commons at: []. Available for use under [|Creative Commons Attribution-Share Alike 3.0 Unported] License.
 * 2) Cogongrass (//Imperata cylindrica//). Video uploaded by the UF/IFAS Center for Aquatic and Invasive Plants and the Florida Fish and Wildlife Commission, Invasive Plant Management Section, on Youtube, at: []. Available for use under Standard YouTube License.
 * 3) Map of countries where //Imperata cylindrica// is native and considered invasive. Information obtained from the Global Invasive Species Database at: []. Map modified based on a map from [|www.outline-world-map.com]. Map image available for use with credit under terms of the website.
 * 4) Cogongrass Fire. Video uploaded by the Alabama Forestry Commission, on Youtube at: []. Available for use under Standard YouTue License.
 * 5) //Imperata cylindrica// growing in Singapore along Clementi Road near University Town. Photo by Amanda Lim.
 * 6) //Stylosanthes guianensis//. Image uploaded by Tropical Seeds, on Flickr at: []. Available for use under [|Creative Commons Attribution 2.0 Generic] license.
 * 7) //Mucuna puriens//. Image uploaded by Shobha R, on Wikimedia commons at: []. Available for use under [|Creative Commons Attribution 2.0 Generic] license.
 * 8) Ornamental variant of //Imperata cylindrica// in the National University of Singapore. Photo by Amanda Lim.
 * 9) Kanami Koronadal – Cogon Paper Making. Uploaded by Peter Miguel, on Youtube at: []. Available for use under Standard YouTube License.
 * 10) Section of //Imperata cylindrica// leaf. Photo and annotation by Amanda Lim.
 * 11) Plate featuring the flowers and seeds of //Imperata cylindrica//. De Beauvois P (1812). Essai d'une Nouvelle Agrostographie pp. 8, 165, 177, pl. 5, f. 1. Retrieved from the Biodiversity Heritage Library at: [|http://www.biodiversitylibrary.org/page/394087#page/290/mode/1up]. Available in the Public Domain.
 * 12) Inflorescence of an ornamental variant of //Imperata cylindrica//. Photo and annotation by Amanda Lim.
 * 13) Seeds of //Imperata cylindrica//. Photo by Amanda Lim.
 * 14) //Imperata cylindrica// rhizomes, roots, and seeds. Photo uploaded by Marsh, Florida Department of Agriculture and Consumer Services, Bugwood.org, on Wikimedia Commons at: [|https://commons.wikimedia.org/wiki/Category:Imperata_cylindrica#mediaviewer/File:Imperata_cylindrica_2308122.png]. Available for use and annotation under [|Creative Commons Attribution-Share Alike 3.0 Unported] License.
 * 15) Original entry of //Imperata cylindrica// as //Lagurus cylindricus// in //Systema Naturae//. Linnaeus C (1759). Systema Naturae, ed. 2 vol. 2. Pp.878. Retrieved from the Biodiversity Heritage Library at: [|http://www.biodiversitylibrary.org/item/137340#page/105/mode/1up]. Available in the Public Domain.
 * 16) Maximum Parsimony Phylogenetic tree. Hodkinson T, Chase M, Lledó D, Salamin N, Renvoize S (2002). Phylogenetics of Miscanthus, Saccharum and related genera (Saccharinae, Andropogoneae, Poaceae) based on DNA sequences from ITS nuclear ribosomal DNA and plastid trnL intron and trnL-F intergenic spacers. J Plant Res. 115(5):381–92. Used and annoted with permission from author, obtained by email.
 * 17) Phylogenetic tree. Burke SV, Wysocki WP, Zuloaga FO, Craine JM, Pires JC, Edger PP, et al. (2016). Evolutionary relationships in Panicoid grasses based on plastome phylogenomics (Panicoideae; Poaceae). BMC Plant Biol. 16(1):140. Available for use and annotation under [|Creative Comons Attribution 4.0] International License.