Rediscovery of Thismia kobensis and Insights into Fairy Lanterns
Researchers from Kobe University in Japan revisited the enigmatic plant known as Thismia kobensis, a fairy lantern species long considered extinct for about three decades. Their rediscovery in Japan unveils new facets of these unusual plants that have intrigued botanists for generations.
Historically, green leaves and photosynthesis were viewed as essential features of plants, yet some organisms have evolved alternative nutrition strategies. Thismia kobensis is one such plant that lives underground and relies on interactions with other organisms rather than photosynthesis. Its striking appearance, paired with a challenging growing habit, makes it a rare find and limits observation to specific locales.
Fairy lanterns are known for their hidden underground life and the way their colorful flowers emerge above the soil, sometimes resembling mushrooms. About 90 species of Thismia exist, though many are only known from their original discovery sites, and a number may have disappeared.
One of these taxa, Thismia kobensis, was first identified in 1992 in Kobe, Japan. Industrial development later destroyed its habitat, leading to its presumed extinction. More than 30 years later, researchers reported a rediscovery in Sanda, a city about 30 kilometers away, in a study published in Phytotaxa. This unexpected find prompts reevaluation of the genus and its evolutionary trajectory.
The team proposed an updated definition for kobensis to complement the original description based on an incomplete museum specimen. Their review clarifies differences between kobensis and closely related species such as Thismia huangi, contributing to a refined understanding of the genus.
The rediscovered kobensis is characterized by a short, broad ring and numerous short hairs on its stigma. Based on a careful assessment of morphological features, Thismia kobensis is recognized as a distinct species with a unique evolutionary history.
A newly documented location marks Thismia kobensis as the northernmost Asian fairy lantern recorded to date. This expanded distribution could shed light on systematic relationships and biogeography among fairy lanterns. By comparison, Thismia americana was once thought related to species in Australia and New Zealand, highlighting surprising distribution patterns within the genus.
Missing Thismia americana
Discovered more than a century ago, Thismia americana is the sole fairy lantern type documented in North America. It was observed for many years on a moor near Chicago but is now considered extinct, mirroring trends seen in related species across other continents.
The persistence of Thismia americana remains largely unknown in tropical and temperate North American regions, especially given its closest relative, Thismia rodwayi, which is found in Australia and New Zealand. This unusual geographic spread continues to puzzle botanists and invites further study of migration and diversification within the genus.
Morphological studies suggest that Thismia cobensis may be the closest living relative of Thismia americana, although similarities in inner floral structures hint at a complex evolutionary relationship. The absence of nectar glands in both species supports a potential connection, while differences in external morphology point to independent adaptations driven by local pollinators.
The current understanding indicates that Thismia americana and cobensis may share lineage traits without one being directly derived from the other. Regional distributions remain discrete, and biogeographical patterns may involve ancient migrations through land bridges that connected major landmasses. The idea that East Asian and North American populations reflect historical movements across the Beringian connections continues to intrigue researchers.
Overall, the rediscovery of Thismia cobensis after thirty years deepens knowledge about fairy lanterns and their biogeography. As the northernmost Asian fairy lantern documented, this finding contributes valuable context to the evolutionary history of the entire group.
Reference work: https://www.mapress.com/pt/article/view/phytotaxa.585.2.2
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