Quercus centenaria L.M. González

West Mexico (Jalisco, Nayarit); 100-2250 m;

20-30 m; buttressed trunk, to 1.20 m in diameter;

8-22 cm x 3-8; evergreen; subcoriaceous; more or less narrowly elliptic, or oblanceolate to lanceolate; apex acute to acuminate, sometimes obtuse; base narrow, rounded or subcordate, often oblique, sometimes cuneate; margin slightly thickenned, undulate, entire or with 2-8 teeth or mucronate lobes in apical half, sometimes in the whole margin; adaxially lustrous, papillose, with some scattered, stellate, 4-10 rayed hairs, becoming glabrous except on the midrib; abaxially tawny pruinose, papillose, with scattered stellate and acicular trichomes, then glabrous; (6)10-15(20) veins pairs, impressed above; petiole 1.5-2.5 cm long, more or less glabrous;

in June; 3-7 male flowers on a 6-12 cm long, glabrescent rachis; perianth campanulate, yellow-brown, sometimes purplish, sessile; 5-8 stamens with hairy anthers; female flowers at leaves-axils, 2 to 5 together, with 3 stigmas 1.5 mm long;

acorn long-ovoid,2-2.5 cm long, truncate at base, brown, then glabrous; solitary or to 5 together on 2-5 cm long peduncle; enclosed 1/3 or less in the cup; cup shallow, with a thin rim, 15-20 mm in diameter, pale brown, on a 3-8 mm long pedicel; cupscales triangular, round at apex, ciliate at margin; maturing in one year, from August to October;

– Sub-genus Quercus, Section Quercus, Series Leucomexicanae; – Close to Q. lancifolia (but the latter has a petiole less than 1 cm long, 2-rayed fasciculate hairs adaxially, the same abaxially with a lustrous, not pruinose epidermis, a 2.5-4 cm long acorn with a related cup) – Premium timber tree. – Possible confusion with Q. martinezii (which has 8-14 veins pairs, abaxial face with a dense yellow or grey pubescence, glandular wormlike trichomes on both faces especially on the veins, a higher elevation habitat, to 2700 m) – Possible confusion as well with Q. vicentensis , which has up to 20 vein pairs, abaxially tomentose, and a different range (the whole Central America)