Over 1000 people thought to have died in Indonesia, Malaysia, and Thailand as a result of Cyclone Senyar.

At least 1000 people are thought to have died, with more than 2700 more known to have been injured and more than 500 still missing after Cyclone Senyar swept across Sumatra and Peninsula Malaysia on 26-28 November 2025. The storm formed as a tropical depression in the Strait of Malacca on 22 November 2025, intensifying to become a tropical cyclone before making landfall on the northern part of Sumatra at about midnight on 26 November 2025. The storm moved southwards along the coast of North Sumatra, before sweeping back across the Strait of Malacca to make landfall on Peninsula Malaysia on 27 November. On 28 November the storm swept out over the South China Sea, where it dissipated several days later without making landfall again.

Flooding in Padangsidimpuan, North Sumatra on 26 November 2025. Badan Nasional Penanggulangan Bencana/Wikimedia Commons.

The passage of Cyclone Senyar resulted in at least 753 deaths on Sumatra, with a further 2600 injured and 526 people still missing, largely as a result of flooding and landslides. Over 1.2 million people on the island have been displaced because of the storm with about 3.3 million affected in some way, across the provinces of North Sumatra, West Sumatra, and Aceh. The storm is reported to have destroyed 3600 homes, and damaged a further 5800, along with 344 bridges and 324 schools.

A woman clearing mud from a house in the town of Meureudu in Aceh Province, Sumatra, following the passage of Cyclone Senyer. Hotli Simanjuntak/EPA.

The storm caused less damage in Peninsula Malaysia, where people had more time to prepare, with three fatalities, and 34 000 people evacuated from high-risk areas ahead of the storm. However, in neighbouring part of southern Thailand, flooding associated with the storm killed at least 267 people, with most of the fatalities occurring in Songkhla Province, according to government figures; although some sources have accused the government of downplaying the size of the disaster, with suggestions that more than 1000 people may have died in Songkhla Province alone. In addition, at least 102 people were injured, with two homes destroyed and 1074 damaged, along with 228 roads, 12 bridges, 41 schools and 38 temples. The city of Hat Yai in Sonhkla Province received 372 mm of rain on 21 November, more than is typical for the entire month of November, and more rain than has fallen on the city in a single day in 300 years of records.

Flooding in Songkhla Province, southern Thailand, on 26 November 2025. AP.

Tropical storms, called Cyclones in the Indian Ocean and South Pacific, are caused by solar energy heating the air above the oceans, which causes the air to rise leading to an inrush of air. If this happens over a large enough area the inrushing air will start to circulate, as the rotation of the Earth causes the winds closer to the equator to move eastwards compared to those further away (the Coriolis Effect). This leads to tropical storms rotating clockwise in the southern hemisphere and anticlockwise in the northern hemisphere. These storms tend to grow in strength as they move across the ocean and lose it as they pass over land (this is not completely true: many tropical storms peter out without reaching land due to wider atmospheric patterns), since the land tends to absorb solar energy while the sea reflects it.

The formation of a tropical cyclone. Natural Disaster Management.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

However, Cyclone Senyar is unusual in that it formed in a part of the world not usually prone to tropical storms; it is only the first such storm ever to form in the Strait of Malacca, and the second to cross these waters, after Typhoon Vamei, which formed in the South China Sea in 2001, and crossed Peninsula Malaysia from east to west. This is because the Strait of Malacca is close to the equator, an area where it was once thought that tropical storms could not form, as the Coriolis Force is not strong enough. However, warming global sea temperatures appear to be making this possible, as more heat is effectively more energy, and this is the fifth such near-equator storm of 2025. This means that communities in these areas are not as used to tropical storms as communities in areas where they are a long-standing problem, and infrastructure has not typically been built with large storms in mind, greatly increasing the damage and casualties caused when they appear.

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Thismia sitimeriamiae: A new species of Parasitic Plant from Terengganu State, Peninsular Malaysia.

The Family Thismiaceae comprises 3-5 genera (two genera are sometimes separated out and placed within a family of their own) of Parasitic Monocotyledonous Plants within the Order Dioscoreales, which also includes Yams. These Plants parasitise the Mycorrhizal Fungi of other Plants, obtaining nutrients from the Fungi, but not providing the Fungi with anything in return. The genus Thismia currently contains 86 species, predominantly from tropical Asia and Australasia, although there are species known from the Americas and temperate Asia. However, the diversity of the group is not that well understood, as these Plants, which are non-photosynthetic, only protrude above the ground during their breeding season, when they produce flowers a few centimetres high. This means that many Thismia species are known only from a single specimen, and we have little idea how widespread they really are or how much variation there is within species. 

The Malaysian state of Terengganu appears to be somewhat of a biodiversity hotspot for Thismias, whith six species reported there to date; Thismia alba, Thismia aseroe, Thismia domei, Thismia javanica, Thismia latiffiana, and Thismia terengganuensis. This diversity appears to be linked to the primary rainforests of the state, which have been disappearing rapidly in recent decades, which raises interesting conservation questions for the genus, which is hard to raise in captivity or transplant to new locations, due to its dependence on (unknown) Fungal hosts.

In a paper published in the journal Phytokeys on 29 June 2021, Mat Yunoh Siti-Munirah of the Forest Research Institute Malaysia, Nikong Dome of DigitalDome Photography, and Chris Thorogood of the Department of Plant Sciences at the University of Oxford and the University of Oxford Botanic Garden, describe a new species of Thismia from the Hulu Nerus Forest Reserve in the State of Terengganu.

 

Hulu Nerus Forest Reserve (black circle), where the new species was discovered. Siti-Munirah Mat Yunoh et al. (2021).

The new species was discovered by Nikong Dome beside a mountain trail in the forest reserve in 2019, and is named Thismia sitimeriamiae, in honour of his mother, Siti Meriam, honour of her unparalleled support for his conservation activities and her help in maintaining his plant collections. The species was originally discovered at two locations beside the trail in December 2019, but a return visit in February 2020 found that one of these sites had been destroyed by Wild Boar activity, and only a single Plant was growing at the other. A follow up visit in December 2020 again found only a single Plant growing at this site, and was unable to locate any other sites where the species was growing.

 

Thismia sitimeriamiae. (A) The habitat in Gunung Sarut, in the State of Terengganu, Peninsula Malaysia. (B) The habit of flowering specimen. (C) A fruiting specimen (in situ). Siti-Munirah Mat Yunoh et al. (2021).

Thismia sitimeriamiae produces a single conical orange flower on an unbranching stem covered by residual, scale-like, non-photosynthetic white leaves arranged in a spiral pattern. The whole Plant stands about 2.2 cm heigh, and is easily overlooked in the forest leaf-litter. 

 

Illustration of Thismia sitimeriamiae. (A) Cross section of perianth showing pendulous stamens (above) and slender pistil (beneath). (B) Pistil. (C) Aerial view of flower showing mitre and portions of apical part of floral tube and outer tepals. (D) Fruit. (E) Stamen (showing outer side of connective). (F) Flower, lateral view. (G) Habit, showing inflorescence (flower) and roots. Siti-Munirah Mat Yunoh et al. (2021).

The new species is currently known only from a single location, in a lowland Dipterocarp forest, growing on moist soil in shade, at an elevation of 209 m above sealevel. Since it is known only from a single location, beside a popular tourist trail where there is a high chance of Human disturbance, and less than five specimens have ever been observed, Siti-Munirah Mat Yunoh et al. recommend that the species be treated as Critically Endangered under the terms of the International Union for the Conservation of Nature’s Red List of Threatened Species. 

 

Thismia sitimeriamiae. (A) Habit with roots. (B) Flower, view from below. (C) Aerial view of floral tube (mitre removed). (D) Flower, aerial view. (E) Mitre, lateral view. (F) Ovary and pistil, lateral view. (G) Flower, lateral view. (H) Mitre, lateral view. (I) Stellate trichomes on the outer surface of floral tube. Images not to scale. Siti-Munirah Mat Yunoh et al. (2021).

Thismias, like other non-photosynthetic Parasitic Plants, typically spend much of their time below ground, only emerging to flower, the timing of which can be unpredictable from a Human perspective. Nevertheless, Thismia sitimeriamiae, has only been observed at two localities, flowering and fruiting between December and February, and both of those sites have subsequently been disturbed by the actions of Wild Boars, the first between the initial discovery of the Plant in December 2019 and a follow-up visit to the site in 2020, the second was discovered also to have been destroyed during a visit to the site in June 2021. 

Plants which parasitise Fungi present an interesting challenge to conservationists, since their survival is linked to specific, and usually unknown, Fungal hosts, making them hard to cultivate. Nevertheless, botanic gardens have had some success with other Parasitic Plants, including the Australian Orchid, Rhizanthella gardneri, and Rafflesia in the Philippines, although both of these had known hosts, allowing the transplanting of Plants to new areas. Most members of the genus Thismia have been recorded only once, and the ecology of these Plants is poorly understood, which makes cultivating them unlikely in the near future. This being the case, conservation efforts should be directed at the preservation of their environment as much as possible.

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