Tree to 20 m tall, often smaller and shrubby. Bark dark grey, deeply ridged. Young shoots with a persistent yellow-grey or brown tomentum. Leaves evergreen, to 8 × 4.5 cm, smaller on fertile shoots, elliptic, rounded at the base and the apex, margin spine toothed particularly on juvenile plants, mostly entire or with few teeth on mature plants. They are densely grey-tomentose on both sides when they emerge, becoming glabrous above but the tomentum persisting on the underside. There are up to 9 pairs of impressed veins but fewer on the smaller leaves of mature plants. Petiole grey-tomentose, 5 mm or less. Infructescence 3 cm or less bearing 1 or 2 cupules. Cups hemispherical, to c. 8 × 1.5 cm, with appressed, grey-hairy scales. Acorns ovoid, to 1.8 × 1 cm, about half enclosed in the cup and ripening the first year. (Menitsky 2005; Huang et al. 1999; le Hardÿ de Beaulieu & Lamant 2010).
Distribution China Guizhou, Sichuan, Xizang, Yunnan India Sikkim
Habitat Mountain forests at 1900–3300 m asl.
USDA Hardiness Zone 7
Conservation status Least concern (LC)
At Tregrehan, England, a plant grown from seed from the Jianchuan area of west Yunnan reached 7 m × 12 cm in 2014 (Tree Register 2020) but has since died. A plant at Arboretum des Pouyouleix in France, raised from Yunnan seed sent in 2012, was multistemmed and 2 m tall in 2020. Another plant there raised from seed collected by Josef Soucek in Guizhou in 2013 was 2 m × 2 cm on a single stem in 2020. (B. Chassé pers. comm. 2020).
A tree at the Sir Harold Hillier Gardens, England, (Coombes 479A), collected as Q. rehderiana, is thought to be a hybrid with Q. senescens. It was selected from a batch of young plants raised from seed of Q. rehderiana collected in Yunnan by Allen Coombes in 1998 (Coombes 479) and growing with Q. senescens. This tree resembles Q. rehderiana in its dense, columnar habit but is much faster growing, reaching 11.9 m × 24.3 cm dbh in 2020 (B. Clarke pers. comm. 2020). The leaves are intermediate between those of the parents and are more hairy than Q. rehderiana above and hairy beneath but green. The petiole is also densely hairy.
Described in 1929. The epithet means ‘graying’ (derived from Latin senex = old), in reference to the gray hairs that cover the young leaves.