Sawtooth Oak

Picture of entire sawtooth oak
Basic Information
Tree ID: 
162
Family: 
Beech
Genus and species: 
Quercus acutissima
Description: 
This sawtooth oak is found near the bottom of the hill by the Marsh Botanical Gardens. It has a relatively thick trunk and is flanked by two smaller trees.
Surveyors: 
Chisom Ofomata and Melody Gebremedhin
Location
Area: 
Marsh and Farnam Gardens
Collected Data
Tree shape: 
Pyrimidal/Round
Date of tree entry: 
02/07/2024
Height: 
10.95 m
Diameter at breast height: 
0.26 m

Bark
The sawtooth oak's bark ranges in color from medium to dark gray. It features narrow, clear ridges perpendicular to the ground (Whittemore, 2004).
Twigs & branches
The sawtooth oak's twigs are typically dark brown. Some have 1-5 trichomes (fine, hair-like structures), while others lack them entirely. Their thickness ranges from 2 to 3 mm (Whittemore, 2004). The tree's buds are brown and range from 5 to 8 mm in length. The buds' upper half is pubescent (covered in fine, soft hair-like structures), and they feature long ciliated scales (Whittemore, 2004).
Foilage
The sawtooth oak’s leaf blades have lanceolate or oblong-lanceolate shapes. They tend to be 11 to 21 cm long and 3 to 6 cm wide. Their base may be rounded or truncated. The secondary veins extend from the primary vein to the margin of the tip of the leaf’s toothed edge, with the exception of the most basal secondary vein. Moreover, the secondary veins end in a bristle. The leaves’ teeth are well-developed and number 10-23 on each side of the blade. These teeth end in a 2-5 mm long bristle (Whittemore, 2004). The upper surface of the sawtooth oak’s blade is shiny. It features small, simple hairs. The underside of the leaf is green and also features small unbranched hairs (Whittemore, 2004).
Reproductive Structures
In the female flower, the calyx is attached to the ovary. The anthers are retuse (they have rounded apices). The styles are narrow and not widened at their tips. The peduncle (stalk) measures 0-2 mm in length. The acorns mature during the second autumn after flowering (Whittemore, 2004). The flowers are small, inconspicuous, and usually bloom in May. They are yellowish-green and occur in separate male and female catkins on the same plant (the sawtooth oak is a "perfect", monoecious plant). The female catkins are yellowish-green and borne on spikes, while the male catkins are golden and pendant. The catkins emerge with the leaves (NCSU, n.d.).
Fruit
The acorn cup is roughly hemispherical, measuring 14-15 mm in length and 18-25 mm in width. It covers about 0.3-0.5 of the nut and has a smooth inner surface with hairs. The scales of the cup are narrow and lanceolate or strap-shaped, originating from a short triangular base. They are 8-10 mm long, weakly ribbed, separate from the cup for their entire length, and strongly curved outward. The scales at the cup's edge are longer, but otherwise, there is no distinct difference. The nut is ovoid-shaped or ovoid-cylindrical-shaped, measuring 15-20 mm in length and 13-17 mm in width. The inner surface of the shell is densely covered in fine hairs, with undeveloped ovules near the base. The seed coat sticks to the fruit wall (Whittemore, 2004).
Seasons
  • Sawtooth oak in the winter.
  • Sawtooth oak's leaves in the winter. Image courtesy of Robert Ferraro (inaturalist.org).
  • Sawtooth oak's leaves in the spring. Image courtesy of Utah State University.
  • A bloom on a sawtooth oak in the spring. Image courtesy of https://www.tree-guide.com/sawtooth-oak.
  • Sawtooth oak in the summer. Image courtesy of Utah State University.
  • Sawtooth oak's leaves in the summer. Image courtesy of Utah State University.
  • Sawtooth oak in the fall. Image courtesy of NC State University.
  • The leaf and bud of a sawtooth oak in the fall. Image courtesy of NC State University.
Research
Natural range of distribution: 
Habitat: 
The sawtooth oak thrives in acidic, well-drained, moist soils with full sun exposure (NCSU, n.d.). Although these plants like moisture, they do not grow well in habitats that receive more than 30 inches of annual precipitation (SUNY Orange, n.d.). Outside of these preferences, they adapt to a wide range of moisture, soil, and temperature conditions which allow them to be drought- and cold-tolerant (NCSU, n.d.). As a result, they have developed a range of adaptation that spans from eastern Texas and Oklahoma to northern Florida, through Missouri to New York, and into southern New England (USDA NRCS, 2002).
Origin, history, and uses: 

The sawtooth oak is native to open woodlands across eastern Asia, from northeastern India to northern Vietnam and eastward to Japan and Korea. Introduced to the United States in 1862, it has gradually gained popularity in cultivation over the last five decades. This oak species is extensively planted to provide wildlife, particularly turkeys, with a food source due to its rapid growth and early, abundant fruiting. Furthermore, it has become increasingly favored as an ornamental tree in landscaping due to its appealing shape, quick growth, and ability to thrive in various environmental conditions (Whittemore, 2004).

The sawtooth oak holds cultural significance in various Asian societies, both historically and in the present day. Its leaves were traditionally used as food for silkworms, contributing to the production of silk, which was a crucial export in Asia’s history and played a role in early interactions between Eastern and Western cultures. Additionally, the acorns were utilized medicinally to treat conditions such as hemorrhaging, diarrhea, and menstrual complications. Moreover, the acrorns were used to produce a brown-black dye important for documenting ancient Chinese history (SUNY Orange, n.d.).

The wood of the sawtooth oak shares similarities with other oak varieties, being classified as an extremely hard type of wood (SUNY Orange). With proper preparation (i.e., removal of tannins), Sawtooth Oak acorns can be made suitable for human consumption. However, if eaten raw, they have an intensely bitter taste. Traditionally, acorns were prepared by burying them during the winter season and then unearthing them in spring, followed by repeated rinsing (NCSU, n.d.).

Despite its attractive leaves and abundant acorn production, Quercus acutissima poses challenges due to its invasive spread and competitive nature against native species. Moreover, the absence of a sterile cultivar means that planting Sawtooth Oak as an ornamental tree is no longer advisable (SUNY Orange, n.d.).

Phenology: 
The sawtooth oak undergoes a woody lifecycle (NCSU, n.d.). The top of the plant persists through the winter and grows larger from existing stems in the spring and summer (Balvin, 2021; Sackett, 2016). Plants with this type of lifecycle take several years to grow flowers (Balvin, 2021). The small, inflorescence flowers or catkins begin to bloom in May, along with the leaves (NCSU, n.d.). Additionally, there are separate female and male flowers (NCSU, n.d.). The trees begin to produce large amounts of acorns quite young at 10 years of age and the acorns mature in the fall (NCSU, n.d.). This type of tree has typically dark green leaves that transform into brownish copper in the fall (NCSU, n.d.) The tree is deciduous, but its leaves tend to persist into the winter (NCSU, n.d.). This tree is an exception as it lost its leaves in the winter.
References: 

1. SUNY Orange. (n.d.). Sawtooth oak. Quercus acutissima, International Tree Tour, SUNY Orange. https://sunyorange.edu/inttreetour/quercus_acutissima.html 

2. Whittemore, A. T. (2004). SAWTOOTH OAK (QUERCUS ACUTISSIMA, FAGACEAE) IN NORTH AMERICA. SIDA, Contributions to Botany, 21(1), 447-454. http://www.jstor.org/stable/41969029

3. NC State University. (n.d.). Quercus acutissima. Quercus acutissima (Japanese Silkworm Oak, Sawthorn Oak, Sawtooth Oak) | North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/quercus-acutissima/ 

4. Sackett, S. (2016, October 31). A Brief Overview of Plant Life Cycles. The Permaculture Research Institute. https://www.permaculturenews.org/2016/10/31/brief-overview-plant-life-cycles/

5. Balvin, S. (2021, February 3). Life Cycle of a Plant: Seeds, Shoots and Roots. Woodland Trust. https://www.woodlandtrust.org.uk/blog/2021/03/plant-life-cycle-seeds-shoots-roots/

6. University, U. S. (n.d.). Oak, Sawtooth | TreeBrowser. Retrieved April 21, 2024, from https://extension.usu.edu/treebrowser/catalog/oak-sawtooth

7. USDA NRCS Northeast Plant Materials Program. (2002, February 5). Plant Fact Sheet: Sawtooth Oak. Retrieved April 23, 2024, from https://plants.sc.egov.usda.gov/DocumentLibrary/factsheet/pdf/fs_quac80….

Media and Arts
An Oak to Silk

A poem by Chisom and Melody


There the sawtooth oak stands, 

Imposing in its stature, 

Staking a claim to lands, 

Even those not alotted to it by nature. 


Leaves lined with jagged teeth, 

With a deep rich green pigment, 

Serve as the silkworm’s feast, 

As it weaves intricate silk nets. 


Smooth, delicate, clean, thin,

The silk it spins is timeless.

Rough bark, bristled, brittle within

The sawtooth stews in silence.


But who knows or cares how the sawtooth feels? 

It’s planted as an ornament. 

For shade; for its shape; for the eyes’ appeal. 

The silkworm shares this predicament. 


Yet the sawtooth calls new soils its home

Through the winters, it will last. 

While the silkworm grays, it cannot roam:

Its winged wildness is past.

Comments

Melody Gebremedhin on February 7, 2024: