Fairy lanterns in focus

Abstract

Thismia (Family Thismiaceae) is a genus of flowering plants unlike any other. Known as fairy lanterns, these diverse plants are united by their peculiar appearance and complex floral morphology (Shepeleva et al., 2020). They are distributed primarily across tropical regions of Asia, Australia, and South America and extend into the subtropical and temperate regions of Japan, New Zealand, Australia, and the United States (Dančák et al., 2020). They are mycoheterotrophic, meaning that they obtain their carbon from root-associated fungi; in this case, arbuscular mycorrhizal fungi shared with surrounding green plants. As such, they are completely devoid of functional leaves and chlorophyll and look superficially like fungi rather than plants. They are visible above ground only transiently when emerging to flower and fruit (Guo et al., 2019). Much like the neglected related genus Oxygyne, they are easily overlooked in deep shade or obscured by leaf litter, and so seldom recorded (Thorogood, 2019).Year on year new species discoveries of fairy lantern are made.Indeed the most comprehensive taxonomic revision of the genus in 1938 (Jonker, 1938) covers just a fraction of the 80-90 species now known to science. The most recent cross-genus examination refutes the formerly accepted taxonomy and has brought an astonishing diversity of floral anatomy to our attention (Nuraliev et al., 2021;Shepeleva et al., 2020). Here, we briefly review recent discoveries in the genus, placing focus on Borneo and the Malay Peninsula as a center of diversity of Thismia.Recently, Shepeleva et al. ( 2020) recommended a revaluation of the floral anatomy across the genus Thismia, which is exceptionally complicated and has been characterized rather inconsistently

Rediscovery of the presumably extinct fairy lantern Thismia kobensis (Thismiaceae) in Hyogo Prefecture, Japan, with discussions on its taxonomy, evolutionary history, and conservation

“…Members of the Thismia species usually prefer primary forests, which are currently facing unprecedented levels of destruction. Although Thismia species plants are tiny and inconspicuous, they have been described as one of the most curious and extraordinary genera in the plant kingdom (Thorogood & Mat Yunoh 2021), and their odd appearance and life strategy make them exceptional among herbs (Dančák et al 2018). Owing to its bright orange coloration, T. kobensis could become a particularly iconic species in Japan.…”

“…Consequently, they are particularly sensitive to environmental disturbances, often rendering them both rare and endangered. Fairy lanterns are renowned for their extreme rarity and highly localized occurrence (Thorogood & Mat Yunoh 2021). Currently, ca.…”

“…One example, albeit atypical in habitat and distribution, is T. americana N. Pfeiffer (1914: 123), which has not been found since a few years after its first discovery in a wet prairie in Chicago, Illinois in 1912 (Merckx & Smets 2014). Nonetheless, some Thismia species may have additional unrecognized localities, considering that (i) they get easily covered by fallen leaves because of their dwarf habit, (ii) their flowers usually appear only during a short period of the year (the wet season), and (iii) an isolated population occurring in an area of few square meters is unlikely to survive for long periods (Dančák et al 2020;Thorogood & Mat Yunoh 2021). Therefore, although Thismia species that have not been reported for long periods are considered extinct, it is often difficult to determine whether a focal species is truly extinct.…”

Thismia malayana (Thismiaceae), a new mycoheterotrophic species from Peninsular Malaysia

“…Thismia species exhibit a number of unusual morphological features that continue to fascinate due to their amazing diversity of flower shapes and colours (Feller et al 2022). The flower structure of Thismia is highly specialised to pollination by fungus gnats or other small insects (Thorogood and Siti-Munirah 2021). The flowers often have a complex shape with cup-like or spherical structures and intricate patterns that presumably attract pollinators.…”

Living in the shadows: Gastrodia orchids lack functional leaves and open flowers

“…However, in some non‐photosynthetic plants called mycoheterotrophic plants, the usual polarity of carbon movement from plant to their mycorrhizal fungi is reversed, and these mycoheterotrophic plants exploit all the nutrition from the fungi (Leake, 1994). Mycoheterotrophic plants typically remain belowground most of the time in the dark forest understory, and their aboveground organs appear through the leaf litter only during the short flowering and fruiting period (Leake, 1994; Thorogood, 2019; Thorogood & Mat Yunoh, 2021). A prime example of this is the leafless orchid genus Gastrodia with more than 100 species distributed throughout the temperate and tropical regions of Asia, Oceania, Madagascar, and Africa (Suetsugu, 2019, 2021).…”