Quercus castanea Née

Mexico (Colima, Chiapas, Mexico, Michoacan, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, Morelos, Nayarit, Oaxaca, Puebla, San Luis Potosi, Sinaloa, Sonora, Tamaulipas and Veracruz); Guatemala; 800 - 2600 m (to 3500 m in Guatemala);

8-25 m tall; trunk to 40 cm and more in diameter; crown 4-8 m. diam.;

3-10 x 2-4 cm; leathery, stiff; elliptic, lanceolate, oblanceolate or elliptic-oblong; apex obtuse to pointed, shortly aristate; base obtuse, subcordate, truncate or slightly oblique; margin flat or weakly revolute, cartilaginous, with 1-7 pairs of short aristate teeth in the distal half or 2/3, but sometimes entire (only aristate, without teeth), or toothed only near apex; green, dull, rough, mostly glabrous (except near petiole) above; tomentose beneath with stellate (13-18 crispate rays), stipitate trichomes and sometimes glandular simple hairs, at first yellow then whitish grey, sometimes glabrescent; epidermis abaxially lustrous, bullate; 5-12 pairs of lateral veins slightly impressed above, raised beneath; petiole light yellow brown, more or less pubescent, 3-12 mm long;

May-June ; male catkins 6 cm long, pubescent, with 20-30 flowers; female inflorescences 0.3-0.5 cm with 1-2 flowers;

acorn 5-15 mm, broadly ovoid ; singly or paired, sessil or on a stout stalk 2-5 mm long; enclosed 1/3 in cup; cup halfround to obconical, 7-12 x 3-7 mm, with straight rim and thin pubescent scales; maturing in 1 year, from October to January;

– A. Camus : n° 375; – Sub-genus Quercus, Section Lobatae, Subsection Erythromexicanae; – For Tracey Parker (Trees of Guatemala, 2008), Q. tristis is a true species. In 2017, for S. Valencia-A. as well it is a true species, especially the specimens collected in Chiapas and Guatemala, with the abaxial surface of the leaves completely glabrous, but she thinks that additional studies, mailny with molecular characters, should be done to make the best decision. – Resembles Q. scytophylla which differs in having multiradiate trichomes below with more rays (24-36), the epidermis dull, whitish, papillose beneath, the foliar base acute to attenuate sometimes oblique, the veins impressed above. – Resembles as well Q. sideroxyla which differs in having multiradiate hairs below with 20-30 rays, the abaxial epidermis dull, whitish, papillose. – Q. castanea has often been confused with Q. eduardi and Q. crassipes : Q. eduardi differs in its flat epidermis, flat adaxial blade surface, and fasciculate sessile contorted trichomes on the abaxial surface. Q. crassipes has fasciculate stipitate trichomes on the lower blade surface, the margin is entire, and the cups have an involute rim.