Lithocarpus glaber: Country Or Region Of Origin
Eastern and southern Asia
Plant Profile: Lithocarpus glaber
Names
Japanese Blue Oak, Ring Cupped Oak
Phonetic Spelling:KWER-kus GLAW-kuh
Genus:Lithocarpus
Species:glaber
Family:Fagaceae
The Ring Cup Oak is an evergreen species native to Asia, capable of developing into either a small tree or a sizable shrub. When cultivated, it typically reaches heights of 20 to 30 feet. However, its leaves are prone to cold damage. This tree is adaptable to various soil types, including moist clay, and thrives best in full sunlight.
Its appealing foliage and the acorns it produces in the fall make it a magnet for wildlife. It can be utilized as a small shade tree, a street tree, or for creating privacy and screening.
Lithocarpus glaber Feature Summary
Lithocarpus glaber Image Gallery
Tags
#evergreen
#shade tree
#full sun tolerant
#wildlife plant
#tree
#deer resistant
#acorns
#oak
#screening
#clay soils tolerant
Similar Plants
Lithocarpus glaber Feature Summary
Attributes
Eastern and southern Asia
Mildly resistant to damage by deer. Wildlife eats the acorns.
Acorns (nuts) are edible after tannins are leached or boiled out
Woody
Fruit
Acorns are up to 3/4 inch long. The cup has 5-6 concentric rings and covers approximately 1/3 of the nut. They grow singly or in clusters of 2 or 3.
Nut
Brown/Copper
< 1 inch
< 1 inch
Flowers
Separate male and female catkins in spring.
Gold/Yellow
Insignificant
Catkin
Spring
Leaves
4-8 inch long by 2-4 inches wide elliptical to oblong leaves appear bronzy to purplish in the spring. Becomes glossy dark green in summer. Undersides are gray-green to blue-green with hairs. Margins are entire with teeth near the apex. Bases are rounded. Non-showy fall color is yellowish-green.
Broadleaf Evergreen
Green
Gray/Silver
Red/Burgundy
Purple/Lavender
Gold/Yellow
Simple
Opposite
Elliptical
Oblong
Entire
Serrate
3-6 inches
Glossy
Leathery
Showy
Long-lasting
1-3 inches
Bark
The bark is blackish-brown and smooth at first. It becomes furrowed and rough with age.
Dark Brown
Black
Ridges
Stem
Stems are dark olive green, stiff, thick with pale lenticels. Buds are brown with scales.
Green
Smooth (glabrous)
Cluster of terminal buds
Conspicuous
Enclosed in more than 2 scales
Poisonous to Humans
Stomach pain, constipation and later bloody diarrhea, excessive thirst and urination if young leaves or raw acorns eaten.
Gallotannins, quercitrin, and quercitin.
Leaves
Fruits
Whole Plant Traits
Tree
Poisonous
Broadleaf Evergreen
Multi-stemmed
Rounded
Erect
Oval
Slow
Medium
Medium
Cultural Conditions
Full sun (6 or more hours of direct sunlight a day)
Acid (<6.0)
Neutral (6.0-8.0)
Good Drainage
Occasionally Wet
12-24 feet
Coastal
Piedmont
8b
8a
9a
9b
Clay
Loam (Silt)
Sand
Landscape
Asian Garden
Shade Tree
Screen/Privacy
Specimen
Street Tree
Woodland
Lawn
Lithocarpus glaber Image Gallery
Lithocarpus glaber Attributes
Lithocarpus glaber: Wildlife Value
Mildly resistant to damage by deer. Wildlife eats the acorns.
Lithocarpus glaber: Edibility
Acorns (nuts) are edible after tannins are leached or boiled out
Lithocarpus glaber: Life Cycle
Annual
Biennial
Bulb
Perennial
Woody
Lithocarpus glaber: Recommended Propagation Strategy
Division
Grafting
Layering
Leaf Cutting
Root Cutting
Seed
Stem Cutting
Lithocarpus glaber Fruit
Lithocarpus glaber: Fruit Description
Acorns are up to 3/4 inch long. The cup has 5-6 concentric rings and covers approximately 1/3 of the nut. They grow singly or in clusters of 2 or 3.
Lithocarpus glaber: Fruit Type
Achene
Aggregate
Berry
Capsule
Caryopsis
Drupe
Follicle
Legume
Nut
Pome
Samara
Schizocarp
Siliqua
Lithocarpus glaber: Fruit Color
Brown/Copper
Lithocarpus glaber: Display/Harvest Time
Fall
Spring
Summer
Winter
Lithocarpus glaber: Fruit Length
< 1 inch
1-3 inches
> 3 inches
Lithocarpus glaber: Fruit Width
< 1 inch
1-3 inches
> 3 inches
Lithocarpus glaber Flowers
Lithocarpus glaber: Flower Description
Separate male and female catkins in spring.
Lithocarpus glaber: Flower Color
Gold/Yellow
Lithocarpus glaber: Flower Inflorescence
Catkin
Corymb
Cyme
Head
Insignificant
Panicle
Raceme
Solitary
Spadix
Spike
Umbel
Lithocarpus glaber: Flower Bloom Time
Winter
Spring
Summer
Fall
Lithocarpus glaber Leaves
Lithocarpus glaber: Leaf Description
4-8 inch long by 2-4 inches wide elliptical to oblong leaves appear bronzy to purplish in the spring. Becomes glossy dark green in summer. Undersides are gray-green to blue-green with hairs. Margins are entire with teeth near the apex. Bases are rounded. Non-showy fall color is yellowish-green.
Lithocarpus glaber: Woody Plant Leaf Characteristics
Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen
Lithocarpus glaber: Leaf Color
Gray/Silver
Green
Purple/Lavender
Red/Burgundy
Lithocarpus glaber: Deciduous Leaf Fall Color
Gold/Yellow
Lithocarpus glaber: Leaf Type
Compound (Pinnately , Bipinnately, Palmately)
Fronds
Needles
Sheath
Simple
Lithocarpus glaber: Leaf Arrangement
Alternate
Opposite
Other/more complex
Rosulate
Whorled
Lithocarpus glaber: Leaf Shape
Acicular
Auriculate
Cordate
Cuneate
Deltoid
Elliptical
Filiform
Lanceolate
Linear
Oblanceolate
Oblong
Obovate
Obtuse
Orbicular
Ovate
Palmasect
Palmatifid
Peltate
Pinnatifid
Pinnatisect
Reniform
Rhomboidal
Spatulate
Subcordate
Subulate
Lithocarpus glaber: Leaf Margin
Crenate
Crenulate
Dentate
Denticulate
Doubly Crenate
Doubly Dentate
Doubly Serrate
Entire
Lobed
Serrate
Sinuate
Undulate
Lithocarpus glaber: Hairs Present
No
Yes
Lithocarpus glaber: Leaf Length
< 1 inch
1-3 inches
3-6 inches
> 6 inches
Lithocarpus glaber: Leaf Feel
Fleshy
Glossy
Leathery
Papery
Prickly
Rough
Rubbery
Slippery
Smooth
Soft
Velvety
Waxy
Lithocarpus glaber: Leaf Value To Gardener
Edible
Fragrant
Good Cut
Good Dried
Long-lasting
Showy
Lithocarpus glaber: Leaf Width
< 1 inch
1-3 inches
3-6 inches
> 6 inches
Lithocarpus glaber Bark
Lithocarpus glaber: Bark Description
The bark is blackish-brown and smooth at first. It becomes furrowed and rough with age.
Lithocarpus glaber: Bark Color
Black
Dark Brown
Lithocarpus glaber: Surface/Attachment
Bumpy
Exfoliating
Fissured
Furrowed
Lenticels
Papery
Patchy
Peeling
Ridges
Scaly
Shaggy
Shiny
Shredding
Smooth
Spongy
Lithocarpus glaber Stem
Lithocarpus glaber: Stem Description
Stems are dark olive green, stiff, thick with pale lenticels. Buds are brown with scales.
Lithocarpus glaber: Stem Color
Green
Lithocarpus glaber: Stem Is Aromatic
No
Yes
Lithocarpus glaber: Stem Surface
Corky Ridges
Covered with a powdery bloom (glaucous)
Dull
Hairy (pubescent)
Polished
Smooth (glabrous)
Lithocarpus glaber: Stem Bud Terminal
Cluster of terminal buds
Only 1 terminal bud, larger than side buds
Only 1 terminal bud, smaller than side buds
Lithocarpus glaber: Stem Lenticels
Conspicuous
Not Conspicuous
Lithocarpus glaber: Stem Bud Scales
Enclosed in 2 scales
Enclosed in a single cap like scale
Enclosed in more than 2 scales
No scales, covered in hair
Lithocarpus glaber Poisonous to Humans
Lithocarpus glaber: Poison Symptoms
Stomach pain, constipation and later bloody diarrhea, excessive thirst and urination if young leaves or raw acorns eaten.
Lithocarpus glaber: Poison Toxic Principle
Gallotannins, quercitrin, and quercitin.
Lithocarpus glaber: Poison Severity
High
Low
Medium
Lithocarpus glaber: Causes Contact Dermatitis
No
Yes
Lithocarpus glaber: Poison Part
Bark
Flowers
Fruits
Leaves
Roots
Sap/Juice
Seeds
Stems
Lithocarpus glaber Whole Plant Traits
Lithocarpus glaber: Plant Type
Annual
Bulb
Carnivorous
Edible
Epiphyte
Fern
Ground Cover
Herb
Herbaceous Perennial
Houseplant
Mushroom
Native Plant
Ornamental Grasses and Sedges
Perennial
Poisonous
Rose
Shrub
Succulent
Tree
Turfgrass
Vegetable
Vine
Water Plant
Weed
Wildflower
Lithocarpus glaber: Woody Plant Leaf Characteristics
Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen
Lithocarpus glaber: Habit/Form
Arching
Ascending
Broad
Cascading
Climbing
Clumping
Columnar
Conical
Creeping
Dense
Erect
Horizontal
Irregular
Mounding
Multi-stemmed
Multi-trunked
Open
Oval
Prostrate
Pyramidal
Rounded
Spreading
Vase
Weeping
Lithocarpus glaber: Growth Rate
Slow
Medium
Rapid
Lithocarpus glaber: Maintenance
Low
Medium
High
Lithocarpus glaber: Texture
Fine
Medium
Coarse
Lithocarpus glaber Cultural Conditions
Lithocarpus glaber: Light
Dappled Sunlight (Shade through upper canopy all day)
Deep shade (Less than 2 hours to no direct sunlight)
Full sun (6 or more hours of direct sunlight a day)
Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Lithocarpus glaber: Soil pH
Acid (<6.0)
Alkaline (>8.0)
Neutral (6.0-8.0)
Lithocarpus glaber: Soil Drainage
Frequent Standing Water
Good Drainage
Moist
Occasional Flooding
Occasionally Dry
Occasionally Wet
Very Dry
Lithocarpus glaber: Available Space To Plant
12 inches-3 feet
12-24 feet
24-60 feet
3 feet-6 feet
6-feet-12 feet
Less than 12 inches
more than 60 feet
Lithocarpus glaber: NC Region
Coastal
Mountains
Piedmont
Lithocarpus glaber: USDA Plant Hardiness Zone
8a
8b
9a
9b
Lithocarpus glaber: Soil Texture
Clay
High Organic Matter
Loam (Silt)
Sand
Shallow Rocky
Lithocarpus glaber Landscape
Lithocarpus glaber: Landscape Theme
Asian Garden
Butterfly Garden
Children's Garden
Cottage Garden
Cutting Garden
Drought Tolerant Garden
Edible Garden
English Garden
Fairy Garden
Garden for the Blind
Native Garden
Nighttime Garden
Pollinator Garden
Rain Garden
Rock Garden
Shade Garden
Water Garden
Winter Garden
Lithocarpus glaber: Design Feature
Accent
Barrier
Border
Flowering Tree
Foundation Planting
Hedge
Mass Planting
Screen/Privacy
Security
Shade Tree
Small groups
Small Tree
Specimen
Street Tree
Understory Tree
Lithocarpus glaber: Resistance To Challenges
Black Walnut
Compaction
Deer
Diseases
Drought
Dry Soil
Erosion
Fire
Foot Traffic
Heat
Heavy Shade
Humidity
Insect Pests
Pollution
Poor Soil
Rabbits
Salt
Slugs
Squirrels
Storm damage
Urban Conditions
Voles
Wet Soil
Wind
Lithocarpus glaber: Landscape Location
Coastal
Container
Hanging Baskets
Houseplants
Lawn
Meadow
Naturalized Area
Near Septic
Patio
Pond
Pool/Hardscape
Recreational Play Area
Riparian
Rock Wall
Slope/Bank
Small Space
Vertical Spaces
Walkways
Woodland
