Một số ghi chú về nhận dạng loài Castanopsis megaphylla Hu – Dẻ gai lá to (Fagaceae) và ghi nhận mới cho hệ thực vật Việt Nam.26 tháng 8, 2019
Notes on identity of Castanopsis megaphylla Hu (Fagaceae), and its new record for the flora of Vietnam
Vương Duy Hưng¹*, Xia Nian He² ̄ ³, Tong Yi Hoa² ̄ ³
In Thai Journal of Botany, No 11 (1)-2019, Page 15 – 24, ISSN 1906-7038
Castanopsis megaphylla Hu was described in 1940, based on several collections from Pingbian County, Yunnan Province of China (H. T. Tsai 60410; H. T. Tsai 61851). Govaerts & Frodin (1998) listed it as a synonym of C. boisii Hickel & A. Camus. Huang et al. (1999) recognized C. megaphylla with a note of "May be the same as the earlier published Vietnamese C. chevalieri Hickel & A. Camus".
After examining the type specimens and consulting the relevant literature, Hung et al. found that C. megaphylla can be easily distinguished from C. boisii by its much larger leaves (25–45 × 8–17 cm vs. 9–16 × 3–6 cm), thicker infructescence rachis (6–9 mm thick vs. 2–3 mm thick), bigger cupules (4–6 cm diam. vs. 2–3cm diam.) and spines completely or almost entirely covering cupule (vs. spines not completely covering the wall of cupule). Castanopsis megaphylla is similar to C. chevalieri in leaf shape, leaf texture, thick infructescence rachis and big cupule, but can be distinguished from the latter by larger leaves (25–45 × 8–17 cm vs. 15–20 × 5–6.5 cm), more numerous secondary veins (16–20 pairs vs. 9–14 pairs), female flowers solitary (vs. three) per cupule. These features clearly suggest that C. megaphylla should be considered as an independent species.
During a field trip to Dien Bien Province, Northwest Vietnam in 2011, Hung et al. found a small population of Castanopsis growing sparsely scattered in broad-leaved forest between 740–850 m asl. Specimens of vegetative and reproductive materials of Castanopsis were collected in the next year. After carefully examining the specimens, Hung et al. concluded that they are conspecific with C. megaphylla Hu, which was only recorded from China before. Thus, it is represented as a new record for the flora of Vietnam. Based on the collections from Vietnam, a detailed description and color figures of this species are provided.
Habit of Castanopsis megaphylla
Leafy branch with male inflorescences and immature infructescences of Castanopsis megaphylla