By Jenna V. Genio
A new, tiny jewel orchid has been discovered on the island of Bohol and named Corybas boholensis as described by researchers from multiple academic institutions in the Philippines, Taiwan, and USA. The finding was recently published in the scientific journal Phytotaxa on December 24, 2020.
Plants in the genus Corybas typically possess a small, single leaf and a single flower with a hood-like dorsal sepal, earning them the nickname “helmet orchids” in the botanical and horticultural worlds. Helmet orchids are also considered “jewel orchids” due to their striking foliage. They are difficult to find and study as they are miniscule and usually hidden amongst forest debris and other plants.
Corybas boholensis was discovered in September 2018 by John Rey Callado during a botanical training exercise in Bohol. Botanists from the Philippine National Museum of Natural History and Philippine Taxonomic Initiative (PTI) studied the collected samples and described the new species as they did with Corybas circinatus, the novel orchid species from Palawan published in May 2020.
The plant, measuring a mere 8.1-16.9mm tall, was found growing in the calcium carbonate rich soil of a shady limestone forest, alongside an unidentified species of creeping Selaginella.
“During a training exercise in survey and specimen collection, I was looking for limestone restricted plants, especially endemic species of Bohol like pteridophytes (ferns and lycophytes). I first saw the creeping Selaginella and beside it was the Corybas,” recounted John Rey Callado.
“It was a serendipitous discovery. We were not intentionally looking for Corybas and yes they are very small and unnoticeable especially without flowers. We were just lucky that we were in the right place at the right time when it was bearing flowers.”
The diminutive and highly unusual orchid, Corybas boholensis, is distinguished by its solid, dark maroon flower, veiny appearance, pale stem, long threadlike sepals and petals, and its short, warty dorsal sepal with dark red pigmentation. It is also highly unusual in having a labellum limb (lip of an orchid) that is almost entirely dark red, with only a narrow band of pale red bordering the swollen boss (tooth).
Corybas boholensis was found growing in a protected area and is critically endangered. Rather than illegal logging and harmful agricultural practices, its greatest threats are poaching and unintentional trampling due to its small size. 50 mature individuals were found in only one limited area.
Numerous rare, endangered species are continually being discovered in the limestone forests of the Philippines. Many are endemic hence cannot be found anywhere else. For botanists, this underscores the need to protect such habitats.
“Limestone karst forests are among the least studied forest types in the country because of inaccessibility and difficult terrain. Majority of limestone karst forests are not protected and face several threats like logging, quarrying, and slash and burn farming. Surprisingly, many recent plant discoveries were from Philippine limestone karst forests, including several species of Begonia and Amorphophallus that are found only there,” continued John Rey Callado.
The full report entitled “Corybas boholensis (Orchidaceae): A New Jewel Orchid Species from Bohol Island, Central Visayas, Philippines” can now be found in Phytotaxa 477, Volume 2. The paper was authored by Danilo Tandang, Tomas Reyes Jr., Rene Alfred Anton Bustamante, John Rey Callado, Edwin Tadiosa, Esperanza Maribel Agoo, and Stephanie Lyon.
Photos by John Rey Callado