Quercus x rudkinii
Common Name(s):
Previously known as:
- Quercus ×dubia
- Phonetic Spelling
- KWER-kus rud-KIN-ee-eye
- This plant has low severity poison characteristics.
- See below
- Description
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Rudkin's oak is a native, naturally occurring hybrid deciduous oak tree in the oak family (Fagaceae). It is a cross between black jack oak, Q. marilandica, and willow oak, Q. phellos, and can be found growing in the eastern to central United States and west to Texas.
Grow Rudkin's oak in full sun in well-drained, moist soils. It can grow up to 70 feet tall. Propagation is by seed.
The leaves can vary from the entire leaves of the willow oak to slightly lobed, taking after the blackjack oak. They can also appear wavy at the edges. Acorns are mature in the second year, as with all red oaks.
Use this tree as a shade tree or street tree.
Insects, Diseases, and Other Plant Problems: See common pests and diseases of oaks in NC to the left. The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common pests and insects.
- See this plant in the following landscape :
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Quercus
- Family:
- Fagaceae
- Life Cycle:
- Woody
- Country Or Region Of Origin:
- Eastern U.S.A. to TX
- Distribution:
- AR , DE , FL , GA , LA , MS , NC , NJ , NY , PA , SC , VA
- Wildlife Value:
- Oak trees support a wide variety of Lepidopteran. You may see Imperial Moth (Eacles imperialis) larvae which have one brood per season and appear from April-October in the south. Adult Imperial Moths do not feed. Banded Hairstreak (Satyrium calanus), which have one flight from June-August everywhere but Florida where they emerge April-May. Edward's Hairstreak (Satyrium edwardsii), has one flight from May-July in the south and June-July in the north. Gray Hairstreak (Strymon melinus), has three to four flights in the south from February-November and two flights in the north from May-September. White-M Hairstreak (Parrhasius m-album) has three broods in the north from February-October. Horace’s Duskywing (Erynnis horatius) has three broods in Texas and the deep south from January-November, and two broods in the north from April-September. Juvenal’s Duskywing (Erynnis juvenalis) has one brood from April-June, appearing as early as January in Florida. Acorns provide food to birds and mammals. The tree provides shelter to birds and mammals. They are host plants to moths and butterflies.
- Edibility:
- Acorns (nuts) are edible after tannins are leached or boiled out.
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Whole Plant Traits:
- Plant Type:
- Native Plant
- Perennial
- Tree
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Erect
- Growth Rate:
- Slow
- Maintenance:
- Medium
- Texture:
- Coarse
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Soil Texture:
- Clay
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
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Fruit:
- Fruit Color:
- Brown/Copper
- Display/Harvest Time:
- Fall
- Fruit Type:
- Nut
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- Acorns mature to chestnut brown with fine hairs in the second year. Scaly cup-shaped cups cover 1/3 to 1/2 of the acorn.
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Flowers:
- Flower Color:
- Brown/Copper
- Gold/Yellow
- Flower Inflorescence:
- Catkin
- Insignificant
- Flower Bloom Time:
- Spring
- Flower Description:
- Male flowers are catkins and female flowers are short spikes
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Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Green
- Leaf Feel:
- Glossy
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Elliptical
- Leaf Margin:
- Entire
- Lobed
- Undulate
- Hairs Present:
- Yes
- Leaf Description:
- The variable green leaves have a rusty-colored underside with margins that can be entire, weakly lobed or wavy. The bases are rounded to slightly cordate and the tips are blunt.
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Bark:
- Bark Color:
- Dark Gray
- Surface/Attachment:
- Fissured
- Ridges
- Bark Description:
- Rough dark gray to black, deeply fissured bark
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Stem:
- Stem Color:
- Brown/Copper
- Stem Is Aromatic:
- No
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Young shoots are densely brown tomentose
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Landscape:
- Landscape Location:
- Lawn
- Landscape Theme:
- Native Garden
- Design Feature:
- Shade Tree
- Street Tree
- Attracts:
- Butterflies
- Moths
- Small Mammals
- Songbirds
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Poisonous to Humans:
- Poison Severity:
- Low
- Poison Symptoms:
- Abdominal pain, constipation then diarrhea (occasionally bloody), depression, frequent urination, discolored urine, jaundice; acorns can obstruct the digestive tract
- Poison Toxic Principle:
- Gallotannins, quercitrin, and quercitin
- Causes Contact Dermatitis:
- No
- Poison Part:
- Fruits
- Leaves
