| Quercus ngochoaensis | |
| Author | Binh & Son 2021 |
| Synonyms | |
| Local names | |
| Range | Vietnam (Mt Ngoc Hoa, in the Ba Vi National Park); 1100 m; |
| Growth habit | 5 meters tall, girth 15 cm; |
| Leaves | 4.5-7.5 cm X 2.1-3.2; thinly leathery; ovate or elliptic-ovate; apex acuminate; base broadly cuneate; margin serrate in apical 2/3, with 5-7 teeth both sides; both faces hairless; 7-10 veins pairs, at an angle of 45-60° with midrib, slightly raised adaxially, strongly prominent beneath as is the midrib; tertiary veins scalariform, remotely visible abaxially; petiole 1-1.5 cm long, white tomentose at first, glabrescent; |
| Flowers | female inflorescenses axillary, erect; |
| Fruits | acorn subglobose, 0.9-1.2 cm long, 0.8-1.2 wide, white tomentose, apex depressed and concave; solitary; sessile; stylopodium 1-1.2 mm long; basal scar 7-9 mm in diameter, slightly convex; cupule cup-shaped 1.2-1.4 cm wide, 0.8-1.1 cm high, enclosing 1/2 to 2/3 of nut; cupscales in 7-8 concentric rings, covered with whitish hairs, with margin entire except the 3 lower ones which are distinctly dentate; maturation in November; |
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Bark, twigs and |
bark whitish grey; twigs hairless, dark green, with lenticels; bud oblong to ellipsoid, 1-3 mm long, 0.5-1 mm wide; bud-scales imbricate into 4-6 rows, ovate-triangular, with obtuse apex and ciliate margin, covered both sides with whitish or yellowish-brown hairs; |
| Hardiness zone, habitat | mixed forests of broadleaves and conifers; calcareous rocky soils; |
| Miscellaneous | -- Sub-genus Cerris,
Section Cyclobalanopsis; -- Closely related to Q. glauca Thunb. from which it differs in having smaller leaves, shorter petioles, foliar margin distinctly serrate in apical 2/3, a cup-shaped cup enclosing to 2/3 of acorn, cup-scales in 7-8 concentric rings, a globose acorn; -- Critically endangered, as there are only 20 mature trees in its range. |
| Subspecies and varieties |
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| Pictures |
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