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scarlet oak

bur oak, burr oak, chêne à gros fruits, mossy-cup oak

Habit Trees, deciduous, to 30 m; lower trunk without stubs of dead branches. Trees, deciduous, to 30(-50) m. Bark dark gray, scaly or flat-ridged.
Bark

dark gray to dark brown, irregularly fissured with scaly ridges, inner bark orangish pink.

Twigs

reddish brown, (1-)2-3.5 mm diam., glabrous.

grayish or reddish, 2-4 mm diam., often forming extensive flat, radiating, corky wings, finely pubescent.

Buds

2-5(-6) mm, glabrous.

Leaves

blade elliptic to ovate or obovate, 70-160 × 80-130 mm, base obtuse to truncate, margins with 5-9 deep lobes and 18-50 awns, lobes distally expanded, sinuses usually extending more than 1/2 distance to midrib, apex acute;

surfaces abaxially glabrous except for minute axillary tufts of tomentum, adaxially glossy light green, glabrous, secondary veins raised on both surfaces.

blade obovate to narrowly elliptic or narrowly obovate, often fiddle-shaped, (50-)70-150(-310) × (40-)50-130(-160) mm, base rounded to cuneate, margins moderately to deeply lobed, toothed, deepest sinuses near midleaf (at least in proximal 2/3), sinuses reaching nearly to midrib, longer lobes grading into shallow lobes or merely simple teeth distally, shallower, compound lobes proximally, secondary veins arched, divergent, 4-5(-10) on each side, apex broadly rounded or ovate;

surfaces abaxially light green or whitish, with minute appressed-stellate hairs forming dense, rarely sparse, tomentum, erect felty hairs absent, adaxially dark green or dull gray, sparsely puberulent to glabrate.

Acorns

biennial;

cup turbinate to hemispheric, 7-13 mm high × 16.5-31.5 mm wide, covering 1/3-1/2 nut, outer surface light to dark reddish brown, glossy, glabrous to puberulent, inner surface light brown, glabrous, occasionally with ring of pubescence around scar, scales often tuberculate, base broad, glossy, margins strongly concave with tips tightly appressed, acute to attenuate;

nut oblong to subglobose, 12-22 × 10-21 mm, glabrous, with 1 or more rings of fine pits at apex, scar diam. 6.5-13.5 mm.

1-3 on stout peduncle (0-)6-20(-25) mm;

cup hemispheric or turbinate, (8-)15-50 mm deep × (10-)20-60 mm wide, enclosing 1/2-7/8 nut or more, scales closely appressed, laterally connate, broadly triangular, keeled, tuberculate, finely grayish tomentose, those near margins often with soft awns to 5-10 mm or more, forming fringe around nut;

nut light brown or grayish, ovoid-ellipsoid or oblong, (15-)25-50 × (10-)20-40 mm, finely puberulent or floccose.

Cotyledons

distinct.

Terminal

buds dark reddish brown, conic to ovoid, 4-7 mm, noticeably 5-angled in cross section, usually silvery- or tawny-pubescent distal to middle.

2n

= 24.

= 24.

Quercus coccinea

Quercus macrocarpa

Phenology Flowering spring. Flowering in spring.
Habitat Poor soils, well-drained uplands, dry slopes, and ridges, occasionally on poorly drained sites Bottomlands, riparian slopes, poorly drained areas, prairies, usually on limestone or calcareous clays (in nw part of range on dry slopes and ridges, prairies)
Elevation 0-1500 m (0-4900 ft) 0-1000 m (0-3300 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; GA; IL; IN; KY; MA; MD; ME; MI; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WI; WV
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[BONAP county map]
from FNA
AL; AR; CT; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MT; ND; NE; NJ; NY; OH; OK; PA; SD; TN; TX; VA; VT; WI; WV; WY; MB; NB; ON; QC; SK
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[BONAP county map]
Discussion

Trees having acorns with broad, distinctly warty cups are sometimes classified as Quercus coccinea var. tuberculata Sargent.

Quercus coccinea reportedly hybridizes with Q. imbricaria, Q. ilicifolia (= Q. ×robbinsii Trelease), Q. laevis, and Q. palustris (E. J. Palmer 1948) and with Q. phellos, Q. rubra, and Q. velutina (= Q. ×fontana Laughlin).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Quercus macrocarpa is one of our most cold-tolerant oak species; it also endures a wide variety of other harsh conditions including poor dry soils and wet, poorly drained, and inundated locations. Putative hybrids with Q. bicolor are common in the northeastern part of its range, where the two species often occur together in wet, poorly drained habitats. The effect of this contact may be partially responsible for morphologic differences across the range of Q. macrocarpa. The large acorns are best developed in the southern part of the range, and a clinal decrease in acorn size and extent of the mossy fringe on the acorn cup seems to occur as one travels from south to north. In the northwest part of its range, Q. macrocarpa varies clinally to smaller, shrubbier forms on bluffs and hillsides, with smaller, less fringed cups, that are the basis of Q. macrocarpa var. depressa (Nuttall) Engelmann and Q. mandanensis Rydberg. These scrubby forms may merit formal recognition after more thorough study; they are treated here as clinal variants of the species. Quercus macrocarpa forms putative hybrids also with Q. alba in the savannah-type regions of the midwest. Putative hybrids with Q. gambelii occur out of the range of Q. macrocarpa.

Quercus macrocarpa is the only oak species native to Montana (in the southeast corner). Wood of Q. macrocarpa is similar to that of Q. alba and produces one of the best and most durable oak lumbers.

Native Americans used Quercus macrocarpa medicinally to treat heart troubles, cramps, diarrhea, Italian itch, and broken bones, to expel pinworms, and as an astringent (D. E. Moerman 1986).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 3. FNA vol. 3.
Parent taxa Fagaceae > Quercus > sect. Lobatae Fagaceae > Quercus > sect. Quercus
Sibling taxa
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Synonyms Q. coccinea var. tuberculata Q. macrocarpa var. depressa, Q. mandanensis
Name authority Münchhausen: Hausvater 5(1): 254. (1770) Michaux: Hist. Chênes Amér., plates 2, 3. (1801)
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