Quercus stellata Wang. - Post Oak, Sand Post Oak, Delta
Native , Occasional
By Steven D. Glenn
Not peer reviewed
Last Modified 01/25/2013
Common NamesPost Oak, Sand Post Oak, Delta
Field IdentificationLarge to medium deciduous tree with alternate, simple, lobed leaves; with pendant catkin-like flowers in early summer followed by acorns in the fall.
Disclaimer: The information provided here is for reference and historical use. We do not recommend nor do we condone the use of this species for food purposes without first consulting a physician.
Native American often used the acorns for a variety of food and drinks, usually by removing the tannins by boiling the nuts or soaking them in lye water. (Moerman, 1998)
Disclaimer: The information provided here is for reference and historical use. We do not recommend nor do we condone the use of this species for medicinal purposes without first consulting a physician.
Used by Native Americans to treat a variety of maladies including dysentery, mouth and skin sores, fevers, asthma, indigestion, and urinary disorders. (Moerman, 1998)
Other usesWood prized for cabinet work, flooring, finish carpentry, and barrels for beer, wine, and other alcoholic spirits. (Hill, 1952)
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)
The Native Americans used the fiber for constructing baskets, wood for firewood and making tools, and leaves for wrapping dough in bread making, as well as cigarette wrappers. The wood was used by European settlers for making lumber, railroad ties, wagon wheels, and furniture. (Moerman, 1998)
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 the primitive times, the Greeks imagined, people were able to live on acorns.
In a nationwide vote hosted by the National Arbor Day Foundation in 2001, the oak was selected as America's National Tree.
NomenclatureQuercus stellata Wang., Beytr. Teutsch. Holzg. Forstwiss. 78, pl. 6, fig. 15. 1787.
Quercus alba minor (Marsh.) Sarg., Arbust. Am. 120. 1785.
Quercus villosa Walt., Fl. Carol. 235. 1788.
Quercus lobulata Soland. ex J.E. Smith in Abbot, Nat. Hist. Lepidopt. Ins.Georgia. 1: 93, pl. 47. 1797.
Quercus obtusifolia Michx., Hist. Chenes Am. no. 1, pl. 1. 1801.
Quercus drummondii Liebmann, Danske Vidensk. Selsk. Overs. Forh. 1854: 170. 1854.
Quercus stellata var. floridana A de Candolle, Prodr. 16,2: 22. 1864.
Quercus minor (Marsh.) Sarg., Gard. & For. 2: 471. 1889.
HABIT Perennial, deciduous, phanerophytic, tree, diclinous and monoecious, 20-25 m tall.
STEMS Main stems ascending or erect, round. Not exfoliating, light gray or gray, scaly, developing vertical ridges with age. Branches erect or ascending or horizontal. Twigs brown or gray, fluted-terete, 2-5 mm in diameter, smooth and lenticellate, with simple and two-six-armed erect to appressed hairs and semi-scurfy, brown or light brown on 1st-2nd year twigs, becoming white or light gray on older twigs, moderately densely or densely distributed. 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 s at twig apices and scattered along stem. Terminal bud ovoid, blunt; axillary buds ovoid, blunt. Bud scales dark brown or brown to reddish-brown, imbricate, with short and unbranched appressed brown or light brown hairs, moderately densely distributed throughout. Bud scale scars encircling the twig. Leaf scars crescent to occasionally half-round. Vascular bundle scars numerous and 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, 0.7-1.5 cm long, with two-six-armed fasciculate erect to appressed brown hairs, moderately densely or densely distributed throughout. Leaf blades: abaxial surface yellowish green to light green (occasionally yellow-brown due to extreme density of appressed bulbous glandular hairs- see below; occasionally semi-glaucous); adaxial surface green to dark green and often glossy; elliptic or obovate or obtriangular (often in cruciform shape due to expanded distal lobes), bilaterally symmetric, 5-15 cm long, 4-11 cm wide, chartaceous; pinnately veined; base usually obtuse, sometimes cuneate; margin 2-3 lobed, 1/4 - 7/8 the distance to the midvein, lobes with obtuse apices lacking bristle tips and rounded sinuses, distal two usually largest; apex obtuse. Abaxial surface papillose and with 3 hair types: a. erect to spreading brown or light brown simple b. erect to spreading brown or light brown asymmetrical (2)6-8(12)-armed fasciculate-stellate and c. appressed yellow to light brown multi-cellular bulbous glandular. Adaxial surface with same 3 hair types but very sparsely distributed throughout (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 light-brown 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 basifixed, with simple and fasciculate brown hairs, opening along the long axis. Filaments free, 1mm long, straight, glabrous. For a review of pollen morphology see Solomon, 1983b.
FRUITS Acorn (glans (Spjut, 1994)) (calybium (Kaul, 1985)) subsessile or short-pedunculate; maturation annual. Acorn ovoid-subglobose, 1.5-2 cm long, comprised of 2 parts- a. the crateriform cup (cupule), enclosing about 1/3 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 densely covered with brown to grey tomentum. Nut olive-green to brown, ovoid-subglobose, 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 hairs, brown or light brown or white, sparsely to moderately densely distributed apically, glabrescent. One study found a size range of 0.28- 2.05 cubic cm with a mean of 0.76 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 in dry substrates of fields, barrens, ridges and woods.
DistributionIndigenous to the southeastern United States, extending north along the coast to Massachusetts.
United States -- AL, AR, CT, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, MO, MS, NC, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, WV
New York Metropolitan Region -- Native along the coast of the metropolitan area.
Rarity StatusGlobal Heritage Rank -- G5
Connecticut -- Not listed
New Jersey -- Not listed
New York -- Not listed
Species BiologyFlowering May
Fruiting August [week 1] - October [week 3]
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), 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) (Vaughan, 1991).
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).Germination (Young & Young, 1992) (Schopmeyer, 1974)
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.
One study of fall-planted acorns in experimental seedbeds found germination rates of 0-81% across different US provenances (Santamour & Schreiner, 1961).
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.