Quercus muehlenbergii Engelm. - Chinquapin Oak, Chinkapin Oak, Yellow Oak, Yellow Chestnut Oak, Chestnut Oak, Rock Chestnut Oak, Rock Oak
Native , Occasional
By Steven D. Glenn
Not peer reviewed
Last Modified 01/25/2013
Common NamesChinquapin Oak, Chinkapin Oak, Yellow Oak, Yellow Chestnut Oak, Chestnut Oak, Rock Chestnut Oak, Rock Oak
Field IdentificationMedium-sized to large deciduous tree with alternate, simple, toothed leaves; buds clustered near twig ends; catkin-like flowers in spring followed by acorns in the fall.
Medicinal usesUsed by Native Americans to treat vomiting. (Moerman, 1998)
Oak-mast surveys may help wildlife agencies better understand dynamics of fall harvests and may be useful in harvest management models that attempt to stabilize fall harvest rates of game animals (Norman, 2003).
Tannins derived from oaks have been used historically to tan animal hides into leather. (Burrows & Tyrl, 2001)
Oak leaves, buds, bark, and acorns contain tannins which have varying degrees of toxicity in different animals. Although oak foliage and acorns provide valuable food for many wildlife species and even some livestock, oak toxicosis, a urinary and digestive tract disease can occur when some animals are forced to subsist on oaks exclusively for several days. Poisoning is rare in humans due to the large amounts needed to ingest to cause symptoms. (Burrows & Tyrl, 2001)
Dryads (or "tree spirits") are nymphs associated with Greek mythology which live near, or in, trees. Dryads are born bonded to a specific tree, originally, in the Indo-European Celtic-Druidic culture, an oak tree. Drys in Greek signifies 'oak,' from an Indo-European root *derew(o)- 'tree' or 'wood.'
In a nationwide vote hosted by the National Arbor Day Foundation in 2001, the oak was selected as America's National Tree.
Quercus muehlenbergii Engelm., Trans. Acad. Sci. St. Louis 3: 391. 1878.
TYPE: USA, Pennsylvania, Conestoga River near Lancaster, (Types: not designated? B, PH)
Quercus prinus var. acuminata Michx., Hist. Chenes Am. no. 5, t. 8. 1801. Quercus castanea Willd. ex Muhl., Neue Schrift. Ges. Naturf. Fr. Berlin 3: 396. 1801. not Nee 1801.
Quercus castanea macrophylla Hampton, Ann. Rep. Ohio State For. Bur. 1: 195. 1886.
Quercus acuminata (Michx.) Sarg., Gard. & For. 8: 93. 1895.
*Quercus brayi Small, Bull. Torrey Bot. Club 28: 358. 1901.
*Quercus muehlenbergii var. brayi Sarg., Bot. Gaz. 65: 442. 1918.
Quercus muehlenbergii f. alexanderi Trel., Mem. Natl. Acad. Sci. 20: 111. 1924.
variant spelling- muhlenbergii
HABIT Perennial, deciduous, phanerophytic, tree, diclinous and monoecious, 25-30 m tall (rarely shrubby on drier sites).
STEMS Main stems ascending or erect, round. Bark gray, flaky to papery. Branches erect or ascending or horizontal. Twigs brown to dark red-brown or gray, fluted-terete, 2-5 mm in diameter, smooth and lenticellate, glabrous or 1st year twigs sparsely to densely beset with long simple, fascicled, and rotate-stellate brown to light brown erect to spreading hairs. Pith white, 5-pointed, continuous, nodal diaphragm absent. Sap translucent. For an anatomical study of the xylem see Tillson & Muller, 1942.
BUDS Terminal and axillary present, clustered at twig apices and scattered along stem. Terminal bud ovoid, blunt; axillary buds 1 per axil, ovoid, blunt. Bud scales brown to light brown, imbricate, with short and unbranched erect or appressed brown to light brown hairs, sparsely to moderately dense, distributed throughout and especially marginally. Bud scale scars encircling the twig. Leaf scars half-round to crescent-shaped. Vascular bundle scars numerous, scattered.
LEAVES Alternate, simple, (appearing pseudo-opposite or pseudo-whorled at twig apices), crowded toward stem apex or spaced somewhat evenly along and divergent from stem. Stipules lateral, free from the petiole, linear, caducous. Petiole adaxially flattened, 1-3.5 cm long, occasionally glabrous, more often with simple and two-five-armed fasciculate light-brown to brown erect or spreading hairs, sparsely to moderately distributed throughout; not glabrescent. Leaf blades: abaxial surface light green and usually glaucous, adaxial surface green, narrowly elliptic or oblanceolate or elliptic or obovate, bilaterally symmetric, 6-16 cm long, 3-10 cm wide, chartaceous, pinnately veined with 9-14 pairs of secondary veins; base cuneate or obtuse or truncate; margin large-toothed or shallowly-lobed, the apices usually callus-tipped but lacking bristle tips; apex acute to semi-acuminate. Abaxial surface papillose and with 3 hair types: a. erect to spreading simple b. erect to spreading asymmetrical two-five-armed fasciculate and c. appressed symmetrical 6-10(12)-rayed rotate-stellate, all brown to light brown or white, moderately densely to densely distributed throughout. Adaxial surface with erect or spreading simple and two-five-armed fasciculate hairs, brown to light brown or white, sparsely or moderately densely distributed throughout. Multi-cellular bulbous and stellate hairs on adaxial side of immature leaves only (Hardin, 1979a)(Thompson & Mohlenbrock, 1979). For an overview of the phenology and the variability and density of hairs due to ecological factors and hybridization see Hardin, 1979b.
FEMALE INFLORESCENCES Coetaneous, spike consisting of a single flower (sometimes 2-3), in axils of current year leaves, subsessile initially, sometimes becoming short-pedunculate in fruit, surrounded by a cupule which is persistent, accrescent, and indurate in fruit (acorn cap). There has been debate over the years regarding the true ontogenetic nature of the cupule. Originally thought to be an involucre of bracts, recent research suggests that the cupule is a complex partial inflorescence derived from stem tissue, see Abbe, 1974;Brett, 1964;Foreman, 1966;MacDonald, 1979;Fey & Endress, 1983. Each cupule subtended by 3 minute, caducous bracteoles.
FEMALE FLOWERS Perianth of one whorl, minute, fragrance absent. Calyx urceolate, of fused sepals. Carpels 3. Locules 3, each containing 2 ovules. Styles 3, each with 1 stigma. Ovary inferior. Placentation axile.
MALE INFLORESCENCES Coetaneous, compound, solitary or fascicled spikes; pendant, catkin-like; in leaf axils of previous year. Rachis moderately to densely covered with brown to white simple and fasciculate hairs; elongating with age, with 1-3 sessile flowers per node, each flower subtended by a small, sessile caducous bracteole.
MALE FLOWERS Perianth of one whorl, fragrance absent. Calyx actinomorphic, campanulate, of fused sepals. Sepal lobes 3-6, ovate-obovate with brown pilosity, moderately dense to densely distributed throughout. Stamens (4)6-9(12), exserted, surrounding tuft of brown hairs. Anthers glabrous, basifixed, opening along the long axis. Filaments free, 1mm long, straight, glabrous (Rowlee, 1900). For a review of pollen morphology see Solomon, 1983b.
FRUITS Acorn (glans (Spjut, 1994)) (calybium (Kaul, 1985)) subsessile or pedunculate to .8 cm; maturation annual. Acorn ovoid-oblong, 1.5-2.5 cm long, comprised of 2 parts- a. the crateriform cup (cupule), enclosing about 1/4 to 1/2 of the base of the nut; and b. the nut, 1-seeded by abortion. For a hypothesis that the first ovule fertilized suppresses the normal development of the others see Mogensen, 1975. Cupule exterior composed of indurate, imbricate, tightly appressed scales moderately to densely covered with brown to grey tomentum. Nut olive-green to brown, ovoid-oblong, with large light-colored circular cupule scar at base and apiculate at the distal end, initially with minute short appressed to spreading simple and fasciculate brown or light brown or white hairs, sparsely to moderately densely distributed apically, glabrescent. One study found a size range of 0.58-2.74 cubic cm with a mean of 1.13 cubic cm and a correlation between smaller acorn size with increasing latitude see Aizen & Woodcock, 1992.
SEEDS Embryo with two large fleshy cotyledons, endosperm lacking. (Young & Young, 1992)
HabitatUsually occurring on mesic calcareous substrates of forests, slopes and thickets.
Indigenous to eastern North America.
United States -- AL, AR, CT, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MS, NC, NE, NJ, NM, NY, OH, OK, PA, SC, TN, TX, VA, VT, WI, WV
Canada -- ON
New York Metropolitan Region -- Native in isolated regions of calcareous substrates in Warren and Sussex Counties, New Jersey and Fairfield County, Connecticut; with possible outliers in Rockland and Westchester Counties, New York.
Global Heritage Rank -- G5
Connecticut -- Not listed
New Jersey -- S3
New York -- Not listed
August - OctoberOften masting, for an investigation on the effects of weather on acorn yields see Sharp & Sprague, 1967. For a study suggesting that masting is effected by weather in conjunction with inherent reproductive cycles see Sork, et al., 1993.
Small predators of acorns facilitate dispersal by dropping undamaged nuts and failing to recover cached nuts. These include Sciurus carolinensis (gray squirrel), Sciurus niger (fox squirrel), Glaucomys volans (Southern Flying Squirrel), Tamias striatus (eastern chipmunk), Peromyscus leucopus (white-footed mouse), Peromyscus maniculatus (deer mouse) and Quiscalus quiscula (common grackle) and Cyanocita cristata (blue jay). (Ivan & Swihart, 2000) (Smith, 1972) (Briggs & Smith, 1989) (Wolff, 1996) (Bosema, 1979) (Darley-Hill & Johnson, 1981) (Johnson & Webb, 1989) (Johnson, et al., 1993)(Stapanian & Smith, 1984). In addition, one study found that many predators preferred the basal end of the acorn and consumed only 30-60% of the cotyledon. A chemical analyses of acorns from two species revealed that the concentration of protein-precipitable phenolics (primarily tannins) was 12.5% (Q. phellos) and 84.2% (Q. laevis) higher in the apical portion of the seeds where the embryo is located, suggesting that many acorn consumers consistently eat only a portion of the cotyledon of several species of acorns and thereby permit embryo survival. (Steele, et al., 1993).
Probably included in the diet of the grey fox (Urocyon cinereoargenteus) (Scott, 1955), eastern wild turkeys (Meleagris gallopavo silvestris) (Norman, 2003), and white-tailed deer (Odocoileus virginianus) (Bryant, et al., 1996).
Acorns of members of the white oak group have little or no dormancy and germinate naturally soon after falling, germination is hypogeal. For germination to occur the moisture content of the acorns must not drop below 30-50%. It is usually impractical to store acorns for more than 6 months, however storage in sealed containers or in sand at 32-36dF is probably best. In general, seed of the white oaks lose viability more rapidly in storage over winter than seed from the black oaks.
General rules for collecting and storing acorns: 1. Collect acorns before they lose much water. 2. Ensure acorns are fully hydrated, soak in clean tap water overnight before placing them in storage. 3. Surface dry the acorns just before depositing them in storage to reduce mold growth. 4. Place acorns into cold storage as soon after collection as is possible. (Connor, 2004)
In one study (Q. phellos and Q. laevis), germination experiments revealed equal or greater germination frequencies for partially consumed acorns than for intact acorns. (Steele, et al., 1993).
For a propagation protocol for growing bareroot oaks see Hoss, 2004.