COVERCOVER STORY STORY

Plants of the PlantsWorld of the Diverse,World Fascinating…and Threatened

Anurag Dhyani

The theme of theThe theme of the World World Wildlife Wildlife Day Day 2020, 2020, “Sustaining “Sustaining all alllife life on on earth”, earth”, centrescentres attention attention on on all wild animal all wild animal and and plant species species as asa component a component of ofbiodiversity. biodiversity. Here’s Here’s a look a look at athow how plant plant species species around around the the world world are are collated,collated, documented, documented, and and assessed assessed to toreveal reveal their their current current status status and and showshow us ushow how different different species species of ofplants are are faring. faring.

18 | Science Reporter | March 2020 COVER STORY OW many plant species are known to science? How many new plant species are discovered annually? How Hmany plant species have documented use? How many plants are threatened with the risk of extinction and what are the global threats to them? These are questions that often pop into our heads. The State of the World’s Plants, a document published by the Royal Botanic Garden (RBG), Kew has begun to provide some answers (the report can be accessed for free online at https://stateoftheworldsplants.com). The first report was published in 2016 to collate the current information about plants status in the world and updated in 2017. The document collates the latest data from reviewed published literature and global databases to show us how plants are faring and reveals their current status. It also highlights important and fascinating research, emerging issues and gaps in our knowledge. Plants of the PlantsWorld of the Diverse,World Fascinating…and Threatened

Anurag Dhyani

The most comprehensive list of all plant names is available on The Plant List, created by the collaboration of Royal Botanic Gardens, Kew and Missouri Botanical Garden. The How Many Plant Species are Known to Science? resource was launched in 2010 and provides accepted scientific names and synonyms of all known vascular plants (flowering An estimated 3,91,000 species are known to plants, conifers, ferns and allies) and bryophytes (mosses and science, of which 3,69,000 are flowering plants (others are liverworts). ferns and mosses). Among these, the number of tree species is 60,065. Interestingly, almost half (45%) of these tree species For a comprehensive list of tree species and their country- are reported in 10 families of the world. level distribution, a new tool GlobalTreeSearch (www.bgci. org/globaltreesearch) has been developed by Botanic Gardens Leguminosae (5,405 species), Rubiaceae (4,827 species) Conservation International. In addition, a recent development and Myrtaceae (4,330 species) are the three leading tree-rich is the Plants of the World Online Portal (POWOP) (http:// families. Brazil (8,715), Colombia (5,776) and Indonesia The theme of the World Wildlife Day 2020, “Sustaining all life on earth”, www.plantsoftheworldonline.org), by RBG, Kew. It provides (5,142) are the top three countries with the most tree species. centres attention on all wild animal and plant species as a component information on plant identification, its distribution, uses, traits, of biodiversity. Here’s a look at how plant species around the world are For students and researchers, there are three plant name threat status and molecular phylogenies. It provides a single collated, documented, and assessed to reveal their current status and resources available on the internet i.e., (1) The International entry point to enable the dissemination of plant information at Plant Name Index (http://www.ipni.org), (2) the World levels accessible to all (collating data in one place from the show us how different species of plants are faring. Checklist of Selected Plant Families (http://apps.kew.org/ other plant databases). Young plant enthusiasts can always wcsp/) and (3) The Plant List (http://www.theplantlist.org/). update themselves through these websites.

March 2020 | Science Reporter | 19 Species-rich Families at an altitude of 1,500 metre above sea level, in South East Brazil. The species photograph was posted by a young The recent report of Kew published this year revealed botanist Reginaldo Vasconcelos in 2013, further identified interesting information about how many plant families are and published by Paulo Gonella with the title “ known to science. In 1883, there were 197 plant families; after magnifica (): the largest new world sundew, 98 years, in 1981, this number increased to 389. Further with discovered on Facebook” in the scientific journal Phytotaxa the introduction of molecular techniques in 1998 similarities in 2015. Interestingly this is one of the three largest species and difference became more robust and clear. As per the latest of Drosera. update, there are 452 vascular plant families around the world identified by scientists. Among them, the five largest families are Asteraceae, Fabaceae, Orchidaceae, Poaceae, Rubiaceae. Asteraceae, commonly known as daisy family is on the top with 32,581 species. The second position is held by Orchidaceae (Orchids) with 28,237 followed by Fabaceae (Legumes) (20,856), Rubiaceae (Coffees and Bedstraws) (13,686), Poaceae (Grasses) (11,434).

Number of Vascular Plants 391,000 Number of Flowering Plants 369,000 Number of Tree species 60,065 New Plant species 1,730 discovered, 2016 New species discovered in 186 India, 2016 By Paulo Gonella - own work CC BY-SA BO, Useful plant species https://commorswikimedia.org/w/indexphp?curid=41949265 31,128 (currently documented) Plant Discoveries in India Plant species used for 28,187 medicine, 2016 The Botanical Survey of India (BSI) has been providing the scientific basis for conservation and sustainable utilisation of Important Plant Areas 1771 plants through survey, inventory, documentation, taxonomic research and by creating awareness since its inception 1890. Vascular Plant Families 452 Botanical Survey of India has discovered 1 new family, 41 new Invasive species 6075 genera, 1,465 new species, subspecies and varieties since 1954. In addition, 186 new species were discovered by Where and How do we Find New Species? Indian scientists during 2016. Among these discoveries, spermatophytes or seed plant (plants which produce seeds) Scientists discover new species of herbs, shrubs, trees and have a big share with 37 per cent of total discoveries. This lower plants every year. These species may be a food crop, group is followed by fungi (20%), lichen (11%) algae (9%) of medicinal use, may provide timber or other social use. In and bryophytes (7%). 2015, the number of new vascular plant species discovered was 2,034; in 2016 this count was 1,730. On average, each year Further, among different states of India, maximum seed about 2,000 species are discovered. These are reported mainly plant species were discovered and reported from Kerala from tropical South America, tropical Asia, continental Africa (35), followed by Arunachal Pradesh (18), Tamil Nadu (17), and Madagascar. Brazil (2,220), Australia (1,648) and China Maharashtra (10), Sikkim (6). The minimum discoveries with (1,597) are the top three source countries for the identification one plant species reported were from Manipur, Nagaland, Rajasthan and Telangana. In Andaman and Nicobar Islands of new species of vascular plants between 2006 and 2015. and West Bengal, only four discoveries were reported. Further The plant discoveries are mostly reported during field low number of species discoveries was reported from Andhra explorations, re-examining of a species with herbarium record Pradesh, Gujarat, Meghalaya, Uttarakhand (each 3), and and of late through social media websites. Here is an interesting Odisha (2) (Source: Plant Discoveries 2016, Botanical Survey example. The first carnivorous plant species discovered through of India). Discovery of more plant species in a state may be Facebook is Drosera magnifica (common name Magnificent linked to the high biodiversity or insufficient explorations in Sundew). The species is endemic to Pico Padre Angelo found the region.

20 | Science Reporter | March 2020 species have documented use with one or multiple uses. Interestingly among them the largest number of plant species with documented use are for medicinal purposes (17,810), followed by plants used in textile and building materials (11,365), environmental issues (8,140), human food (5,538), animal food (3,649), gene resource (5,338), poison (2,503), fuel (1,621), social use (1,382) and invertebrate food (683) (Source: The State of World’s Plants, RBG, Kew 2016). Medicinal plants are plants that possess special properties that qualify them as an article of drug and therapeutic agents, and are used for medicinal purposes. The number of plant species used for medicine was recorded as 17,810 in 2015. Following a thorough analysis of documented medicinal uses, The State of the World’s Plants 2017 reported 28,187 plant species currently recorded as being of medicinal use. In India, among 17000-18000 species of flowering plants, 7263 are medicinal plant species. In our traditional system of medicine, Ayurveda has been reported to use 2559 medicinal plants, followed by Siddha (2267), Unani (1049), Homeopathy (460) and Sowa-rigpa (671). Plant Discoveres 2016, Botanical Survey of India Medicinal plants have become a source of new drug development globally because they contain specific compounds, In one of the largest angiosperm genera Euphorbia, a new mainly alkaloids and terpenoids, that are known to be species has been discovered – Euphorbia gokakensis – from the biologically active or because of known traditional medicinal Belgaum district of Karnataka. It is a dwarf succulent perennial uses. Some plant families have a significantly higher proportion forming a compact cushion up to 0.5 m tall. The species grows of medicinal plant species, for example, Fabaceae (2334), in a rocky habitat. Lamiaceae (1059), Euphorbiaceae (863), Apocynaceae (858), Malvaceae (621), Apiaceae (586), Ranunculaceae (434). Another new species was recorded for the genus This is due to a key class of compounds reported in these Crotalaria; Crotalaria meghalayensis is a herb reaching up to families i.e., alkaloids (Fabaceae, Ranunculaceae), terpenes 15-35 cm height. The plants have pinkish violet flowers and (Lamiaceae), diterpenoids (Euphorbiaceae), cardiac-glycosides were recorded from the Jaintia hills, Meghalaya. This species (Apocynaceae), organic acids (Malvaceae), and coumarins has been assessed as Endangered as per IUCN criteria. (Apiaceae). Gymnosperms are a vanishing group of plants. A gymnosperm Cycas nayagarhensis (Nayagarh Cycas), having a massive stem and large male cones is described from Plants Threatened with Extinction Odisha. Habenaria sahyadrica, a terrestrial herbaceous orchid Twenty one per cent of the global plant species are threatened with pale-greenish white flowers, is described based on the with extinction, as per the criteria of the International Union for collection made on the way to Elival Hills, Palakkad district, Conservation of Nature (IUCN Red List), a figure that needs Kerala. Symplocos parvibracteata, an evergreen shrub up to the concern of scientists, conservationists and communities. 1.0-1.5 m tall, with white flowers, was described based on the Extinction of a plant species is very difficult to prove because collection made from Chemunji Hills, Agasthyamala Biosphere it means that no individual of a species remains alive. Reserve, Thiruvananthapuram, Kerala. The species based on During the year 1978, 10 per cent of the plants were the area of occupancy and number of mature individuals has estimated to be at the risk of extinction. This figure reached been categorised as Critically Endangered. 20 per cent in 2015. To the best of our knowledge, one in five These new discoveries alert us to the need for rapid plant species is estimated to be threatened with extinction. A discoveries of plant species before they become extinct. Some further proportion of species estimated to be in each extinction of them may be useful plants and could be used to develop risk category are Critically Endangered (4%), Endangered life-saving drugs. (7%), Vulnerable (9%), Near Threatened (8%), Least Concern (64%), Data Deficient (8%). Current and Future Dependence In India, 1314 species have been assessed for threatened Useful plants are the plant species that have been documented status as per IUCN Red List of Threatened Species. Among for fulfilling a particular need for humans, animals or the them 6 are categorised Extinct, 2 Extinct in wild, 75 Critically wider environment. To our latest knowledge, 31,128 plant Endangered, 161 Endangered, 131 Vulnerable, 41 Near

March 2020 | Science Reporter | 21 Some Newly Discovered Species

Euphorbia gokakensis (Dr Nilesh V. Malpure, Department Impatiens concinna Impatiens sasidharanii Habeneria sahyadrica of Botany, S.S.G.M. College, (Dr Prabhukumar K.M., Arya Vaidya Sala, Kerala) Maharashtra)

Crotalaria meghalayensis Cycas nayagarhensis Symplocos parvibracteata Drosera magnifica (Prof. Arun K. Pandey, Department of (Dr J.S. Khuraijam, CSIR-NBRI, (Mr Stephan Jeyamary, (Dr Paulo Minatel Gonella, Botany, University of Delhi) Lucknow) JNTBGRI, Kerala) Brazil)

Threatened, 1 Lower Risk/Conservation Dependent, 64 Data or regional plant conservation and botanical importance. The Deficient and 833 are lower Risk or Least Concern. Kew report identified globally a total of 1771 important plant areas, unfortunately very few of them are under conservation Extinction risk of plants is often associated with plant protection. traits and these plant traits are documented in the Kew Report. Epiphytes, zygomorphic flowers, biotic pollination, dioecy, Invasive Species shorter flowering period, lower seed production and diploidy are highlighted plant traits that seem to be associated with An invasive species is a plant, fungus or animal that is not native greater risk of extinction. Some of the major threats to plants to a specific location, and which has a tendency to spread to a are the conversion of natural habitats to agricultural use, degree believed to cause damage to the environment, human road, dam construction, etc. These features will help scientists economy or human health. To date, 6075 invasive species have to set up priority for the conservation of threatened plants been documented around the world. in future. There are three methods to control invasive species: (1) physical control, (2) chemical control and (3) biological Key Strategies for Plant Conservation control. Important Plant Areas (IPAs) is a programme set up in the Physical control deals with the manual removal of the UK. It provides a structure for identifying and maintaining invasive plant by felling, cutting, hand pulling, etc. In chemical the richest sites for plant life, possibly with existing protected control, chemicals like herbicides are used to control the areas, through the protection of the IPA. Plant life here refers growth of species. Biological control is introducing natural to species of algae, fungi, lichens, liverworts, mosses and enemies (insects, fungal pathogens) to the invasive species vascular plants. An area if designated as IPA is considered and which ultimately reduce plant strength and capacity to produce encouraged to gain more awareness and long-term conservation seeds. through ecosystem-based approach. Presently, 6,075 invasive species have been documented around the world, affecting our environment and health. India Important Plant Areas are priority sites based on three is one of the hotspots of colonisation by invasive plant species parameters: (1) presence of threatened plant species: the site and more than 170 species of flowering plants are known to holds significant populations of one or more species that are have established in different parts of the country. of global or regional conservation concern; (2) presence of exceptional botanical richness: the site has an exceptionally Dr Anurag Dhyani is with the Division of Conservation Biology, rich flora in a regional context in relation to its biogeographic Jawaharlal Nehru Tropical Botanic Garden and Research Institute, zone, and (3) presence of threatened habitats: the site is an Karimancode P.O., Palode, Thiruvananthapuram-695562, Kerala. outstanding example of a habitat or vegetation type of global Email: [email protected]

22 | Science Reporter | March 2020