QUERCUS RUGOSA: CHARACTERISTICS, HABITAT, REPRODUCTION AND USES - BIOLOGY - 2025

Quercus rugosa is an arboreal species that belongs to the Fagaceae family. Native to North America from the southern US to northern Mexico, it inhabits coniferous forests between 1,000-3,000 meters above sea level.

It is known as leather oak, horn oak, smooth white oak, hazel oak, oak oak, ax bank oak, honey oak or tocuz oak. Holm oaks are evergreen or semi-deciduous broad-leaved trees and shrubs, since under certain conditions they partially remove their foliage.

Oak (Quercus rugosa). Source: pixabay.com

It is characterized by elliptical, obovate leaves, with toothed margins, rough and rigid, frequently concave at the bottom; with spiky inflorescences that after being fertilized develop a particular fruit of the genus called acorn.

This species is part of the biodiversity of immense forests in temperate zones of the northern hemisphere, being a fundamental element of the temperate forest ecosystems in the Mesoamerican mountains of Mexico and Guatemala.

General characteristics

Morphology

Young leaves of Quercus rugosa. Source: Bodofzt

The oak is an evergreen tree, sometimes deciduous, that can measure from 3-8 m to 30 m in height. The root system is of the deep pivoting type.

The trunk reaches a diameter of 30-50 cm up to 1.5 m in larger plants. The bark is robust dark brown in color with deep cracks that form thick scales.

The ramifications are abundant, fine and tomentose at the beginning, and then thicker and slightly glabrous of brown color. The crown is oval and extensive which provides a closed shadow.

Quercus rugosa is characterized by elliptical-obovate leaves, with straight margins, sometimes toothed, very hard and concave on the underside. Rough in appearance, shiny and smooth on the upper surface, reddish or amber on the underside.

Quercus rugosa leaves. Source: Krzysztof Golik

The flowers are simple and unisexual, the male ones are racemose inflorescences or catkins 3-7 cm long, slightly tomentose. The female flowers in number of 5-30 are distributed through a thin and pubescent peduncle.

The fruit is a solitary ovoid acorn or in a group of 2-3 units, 15-25 mm long and 8-12 mm in diameter. The turgid cotyledons within the pericarp occupy much of the dry weight of the narrow, sharp seed.

Etymology

Quercus is the generic Latin name for oak and holm oak. Rugosa is the Latin adjective that means wrinkled.

Taxonomy

• Kingdom: Plantae
• Subkingdom: Tracheobionta
• Division: Magnoliophyta
• Class: Magnoliopsida
• Subclass: Hamamelidae
• Order: Fagales
• Family: Fagaceae
• Genus: Quercus
• Subgenus: Quercus
• Section: Quercus
• Species: Quercus rugosa Née

Habitat and distribution

Quercus rugosa in its natural habitat. Source: Bodofzt

The oak is a species that adapts to cold and semi-cold temperate climates, and subhumid temperate climates between 1,800-2,800 meters above sea level. With average annual temperature between 12-13 º C and average rainfall between 1,550-1,650 mm annually.

Quercus rugosa grows on flat terrain or slopes of hills and ravines, in very dry or very humid places such as ravines. It is located on deep or superficial soils, slightly stony, of volcanic origin or basalt rock, thin, slightly acidic, humid or dry.

Oak trees are a species of ecological importance in the restoration and rehabilitation of forests despite their low annual growth rate. It is located as part of pine-oak forests, pine forests, mountain mesophilic forests and subtropical scrub.

This species is native to North America and ranges from Arizona and Texas in the US to Chiapas and Guatemala. It is abundant in the mountainous region of western central Mexico, especially in ravines and slopes.

Reproduction

The oak multiplies by sexual reproduction through seeds or vegetative means using shoots of mature plants. The seeds are collected directly from plants free of pests and diseases, with abundant fruit production and excellent phenological characteristics.

The use of seeds collected from the ground is not recommended, due to the low viability and presence of pathogens that destroy the cotyledons. The seeds can be stored in a cool and dry place for a period no longer than three months.

Quercus acorn. Source: pixabay.com

The best time to propagate the oak is in periods of rain, during the months of October and November. The seeds do not require pre-germination treatment, just soak in clean water for 48 hours before sowing.

The sowing is done in seedlings on a medium textured substrate, with good moisture retention capacity and fertile. It is necessary to disinfect the seed and the substrate with a 1% sodium hypochlorite solution to guarantee the sanity of the process.

The seeds are planted on the substrate, lightly covering with a layer of plant material in order to maintain the humidity of the environment. Under these conditions seed germination takes three to five weeks, or up to 10 weeks.

When the seedlings are approximately 5 cm tall, it is recommended to peal in order to eliminate weak plants. Subsequently, the seedlings are transplanted into polyethylene bags and kept in the nursery until they are transferred to their final site.

In the case of vegetative reproduction, oak plants have the ability to develop shoots from stumps. These shoots separated from the base of the trunk can be transplanted and will give rise to a plant with characteristics similar to the mother plant.

Applications

Oak wood is used as firewood and for obtaining charcoal as fuel. Likewise, it is used for the elaboration of piles for fencing, or at an industrial level in the manufacture of paper.

The bark and leaves have a high tannin content, being used in the leather tanning industry. The leaves and fruits constitute a nutritional supplement for cattle, goats and pigs.

Quercus rugosa bark. Source: Krzysztof Golik

The bark has astringent, healing, anti-inflammatory and anti-hemorrhagic properties; It is used to relieve inflammation and stop bleeding caused by insect bites, as well as to treat ulcers and healing of the gums, tighten loose teeth and prevent bleeding.

From the dried and ground fruit, a drink similar to coffee with medicinal properties is made. This infusion allows to mitigate the effects of drunkenness, relieve diarrhea and treat kidney problems, cough, scabies and bleeding.

References

1. Encino bankrupt ax. Quercus rugosa (2018) Mexican Biodiversity. National Commission for the Knowledge and Use of Biodiversity. CONABIO. Recovered in: biodiversity.gob.mx
2. González Villarreal, LM (1986). Contribution to the knowledge of the genus Quercus (Fagaceae) in the state of Jalisco. Botanical Institute. University of Guadalajara.
3. Hélardot, Jean-Louis (2018) Quercus rugosa. Oaks of the World. Recovered at: oaks.of.the.world.free.fr
4. Romero, S., Rojas, EC, & Garay-Velázquez, OH (2007). Presence of hermaphrodite flowers in Quercus rugosa (Fagaceae) in the State of Mexico (Mexico). In Anales del Jardín Botánico de Madrid (Vol. 64, No. 2). Superior Council of Scientific Investigations.
5. Quercus rugosa Neé (2017) SIRE-Technological Packages. Reforestation Information (SIRE) (Conabio-Pronare) 7 pp.
6. Quercus rugosa (2017) Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org