Ludisia Explained

Ludisia (Lus.^[1]) is a genus of orchids that was thought to contain just one species, Ludisia discolor, commonly referred to as jewel orchid. A second species, Ludisia ravanii, from the Philippines, was described in 2013.^[2] Ludisia discolor is native to Southern China, Northeast India, Thailand, Vietnam, the Philippines, Malaysia, Indonesia and Myanmar,^[3] and often cultivated.

Description

They are terrestrial orchids that in their natural setting would be found growing on the forest floor. They are known for their foliage, which is often velvety deep maroon with red veins that run parallel to the centre of the leaf.

Flowers are white with twisting yellow columns. Individual flowers are small but grow in clusters on upright stalks. Flowers in cultivation last a month or more.^[4]

Cultivation

They need high humidity and warm temperatures with low to medium light, and they tolerate extremely low light levels.

Conservation

Like many species today, Ludisia discolor and other species of terrestrial orchids face threats due to climate change and other environmental factors. Studies today that aim to understand more about how orchid species could be cultivated include micropropagation. When micropropagating Ludisia discolor in varying environments, they found that the plant was able to adapt to the environment while maintaining 99% genetic similarity with the parent plant. Now that scientists are able to control the genetic diversity of a plant in varying conditions, it will be beneficial in improving the species’ population numbers.

Apart from climate change and similar environmental factors, the species is currently facing threats of Fusarium oxysporum, which manifests as a stem rot, affecting the flowering of species of orchids.

^[5]

^[6]

Cultivars

Ludisia discolor has two notable cultivars:

• L. discolor 'Alba', an albino variant, and
• L. discolor 'Nigrescens', a mutation often referred to as "black velvet".

Hybrids

Hybrids of Ludisia with other orchid genera are placed in the following nothogenera:

• Dossisia^[7] (Dsi.) = Ludisia × Dossinia
• Goodisia^[8] (Gda.) = Ludisia × Goodyera
• Ludochilus^[9] (Lud.) = Ludisia × Anoectochilus
• Macodisia^[10] (Mcd.) = Ludisia × Macodes

Note that these hybrids are with other genera in the subtribe Goodyerinae, all commonly referred to as jewel orchids.

(The given references are to registered primary hybrids within each given nothogenus.)

References

^[11]

Notes and References

1. Alphabetical List of Standard Abbreviations for Natural and Hybrid Generic Names, Royal Horticultural Society, https://www.rhs.org.uk/plants/pdfs/plant-registration-forms/orchid-name-abbreviations-list.pdf
2. Web site: Ludisia ravanii Cootes & G.Tiong | Plants of the World Online | Kew Science.
3. http://apps.kew.org/wcsp/namedetail.do?name_id=115489 Kew World Checklist of Selected Plant Families
4. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200028741 Flora of China v 25 p 55, 血叶兰 xue ye lan, Ludisia discolor (Ker Gawler) Blume, Coll. Orchid. 113. 1859.
5. Sherif, N. A., Senthil Kumar, T., & Rao, M. V. (2020). DNA barcoding and genetic fidelity assessment of micropropagated Aenhenrya rotundifolia (Blatt.) C.S. Kumar and F.N. Rasm.: a critically endangered jewel orchid. Physiology and Molecular Biology of Plants, 26(12), 2391–2405. https://doi.org/10.1007/s12298-020-00917-9
6. Huang, L. ‐W., Wang, C. ‐J., Lin, Y. ‐S., Chung, W. ‐C., & Chung, W. ‐H. (2014). Stem rot of jewel orchids caused by a new forma specialis, F usarium oxysporum f. sp. anoectochili in T aiwan. Plant Pathology, 63(3), 539–547. https://doi.org/10.1111/ppa.12133
7. Web site: The International Orchid Register / RHS Gardening.
8. Web site: The International Orchid Register / RHS Gardening.
9. Web site: The International Orchid Register / RHS Gardening.
10. Web site: The International Orchid Register / RHS Gardening.
11. Sherif, N. A., Senthil Kumar, T., & Rao, M. V. (2020). DNA barcoding and genetic fidelity assessment of micropropagated Aenhenrya rotundifolia (Blatt.) C.S. Kumar and F.N. Rasm.: a critically endangered jewel orchid. Physiology and Molecular Biology of Plants, 26(12), 2391–2405. https://doi.org/10.1007/s12298-020-00917-9Huang, L. ‐W., Wang, C. ‐J., Lin, Y. ‐S., Chung, W. ‐C., & Chung, W. ‐H. (2014). Stem rot of jewel orchids caused by a new forma specialis, F usarium oxysporum f. sp. anoectochili in T aiwan. Plant Pathology, 63(3), 539–547. https://doi.org/10.1111/ppa.12133