Quercus langbianensis explained

Quercus langbianensis is an uncommon oak tree species in the family Fagaceae.^[1] It is placed in subgenus Cerris, section Cyclobalanopsis, the ring-cupped oaks.^[2] These differ from other Quercus groups in that they have acorns with distinctive cups: usually with substantial rings, made-up of scales that have grown together. This species can be found in sub-tropical and tropical seasonal forests of Vietnam.

Synonymy

A number of species names, previously considered synonyms,^[3] are now considered to be valid.^[4] These very similar species are considered by Binh, Ngoc et al. (2018)^[5] to be a species complex; more information is available in Oaks of the World.^[6]

Other species names previously listed here were:

• Quercus baniensis A.Camus - Vietnam
• Quercus blaoensis A.Camus - Vietnam
• Quercus cambodiensis Hickel & A.Camus [synonyms ''Q. langbianensis'' subsp.'' Cambodiensis'' {{Au|(Hickel & A.Camus) Menitsky}}, ''Q. auricoma'' {{Au|A.Camus}}] - Cambodia
• Quercus camusiae - Vietnam and China (mostly Yunnan).^[7]
• Quercus dilacerata Hickel & A.Camus - Vietnam
• Quercus donnaiensis A.Camus - Vietnam
• Quercus pachyloma [synonym ''Cyclobalanopsis pachyloma '' var. ''mubianensis'' {{Au|(Y.C.Hsu & H.Wei Jen) C.C.Huang}}] - native to S. China and Taiwan.

Description

Quercus langbianensis is an evergreen tree that reaches a height of up to 15 m. The leaves measure 70-140 (up to 170) x 25–40 mm, elliptical-lanceolate to oblanceolate, leathery and glabrous on both sides, with margins having numerous small teeth that are obtuse, wavy near the apex: which is acuminate to slightly caudate; petioles are 15–20 mm and hairless.

The acorns are sub-globose approximately 17–20 mm, covered with fine silky hair (sericeous), pale brown and ripening by September; scars are approximately 10 mm in diameter and convex. Their styles are persistent about 2 mm in diameter. Superficially, the cups are bowl-shaped, 8 x 20–25 mm approximately, enclosing 1/2 or 2/3 of the acorn. Outside and inside the reddish, tomentose acorn has a wall about 3 mm thick. The bracts are formed by 5 to 7 rings, with whole margins.

External links

• • Line drawings, Flora of China Illustrations vol. 4, fig. 378, drawing 5-11 at lower left

Notes and References

1. Web site: Quercus langbianensis. 18 July 2014 . Tropicos.org. Missouri Botanical Garden.
2. Web site: Denk . Thomas . Grimm . Guido W. . Manos . Paul S. . Deng . Min . Hipp . Andrew L. . 2017 . Appendix 2.1: An updated infrageneric classification of the oaks . figshare . 2023-02-24 . xls . amp .
3. http://www.theplantlist.org/tpl1.1/record/kew-173508 The Plant List: Quercus langbianensis Hickel & A.Camus (accessed 10/7/2017)
4. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:325819-2 POWO
5. Binh HT, Ngoc NV, Tagane S, Toyama H, Mase K, Mitsuyuki C, Strijk JS, Suyama Y, Yahara T (2018). A taxonomic study of Quercus langbianensis complex based on morphology and DNA barcodes of classic and next generation sequences. PhytoKeys 95: 37-70.
6. Oaks of the World archive retrieved 16 April 2024
7. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=210000356 Flora of China, Cyclobalanopsis camusiae (Trelease ex Hickel & A. Camus) Y. C. Hsu & H. W. Jen, 1993. 法斗青冈 fa dou qing gang