Lobelia siphilitica: Country Or Region Of Origin
Eastern North America
Plant Profile: Lobelia siphilitica
Taxonomy: Lobelia siphiliticaNames
Blue Cardinal Flower, Great Blue Lobelia, Great Lobelia
Phonetic Spelling:low-BEE-lee-a sigh-fy-LY-tih-kuh
Genus:Lobelia
Species:siphilitica
Family:Campanulaceae
The Great Blue Lobelia is a perennial herb that can reach heights of 3 to 4 feet. Its leaves are arranged alternately and feature a serrated edge. The striking blue flowers begin to bloom in mid-summer and persist into early autumn, boasting a larger size compared to other Lobelia species, with distinctive stripes along the tubular part of the flower.
This plant adds vibrant late summer color to various garden settings, including perennial borders, wildflower gardens, native plant gardens, woodland areas, and naturalized landscapes. It also thrives in proximity to ponds or streams.
In 1993, the Great Blue Lobelia was honored as the Wildflower of the Year in North Carolina, a recognition facilitated by the North Carolina Botanical Garden with support from the Garden Club of North Carolina.
Regarding fire safety, this plant has a medium flammability rating.
Seasons of Interest:
- Blooms: Late summer to fall
- Nut/Fruit/Seed: Fall
Potential issues include damage to the foliage from snails and slugs.
For further details on Lobelia, additional resources are available.
Lobelia siphilitica Feature Summary
Lobelia siphilitica Image Gallery
Tags
#hummingbirds
#showy flowers
#poisonous
#rain garden
#fall flowers
#perennial
#wildlife plant
#showy
#native perennial
#blue flowers
#low maintenance
#herb garden
#fire
#medium flammability
#NC native
#native garden
#naturalizes
#food source fall
#NC Native Pollinator Plant
#late summer flowers
#Coastal OBL
#food source nectar
#food source pollen
#Piedmont Mountains FACW
#food source hard mast fruit
#butterfly friendly
#HS302
#audubon
#meadows
#woodlands
#NC Wildflower of the Year
Similar Plants
Lobelia siphilitica Feature Summary
Attributes
Eastern North America
Its flowers are attractive to hummingbirds and butterflies.
This plant has low resistance to damage from deer.
Perennial
Seed
Division
Wildlife Food Source
medium flammability
Fruit
Displays from August to November
Flowers
Great lobelia is a clump-forming perennial which features an elongated cluster of light to dark blue, tubular, 2-lipped flowers with the three lobes of the lower lip appearing more prominent than the two lobes of the upper lip. The flowers arise from the upper leaf axils forming a dense terminal raceme atop stiff, unbranched, leafy stalks typically rising 2-3' tall. Its flowers are larger than other lobelias and have stripes on the tube portion. Blooms from July to October.
Blue
Raceme
Summer
Fall
Tubular
Leaves
Great lobelia has finely-toothed, lance-shaped, light green leaves (to 5" long). The alternate, stalkless leaves are 2 to 6 inches long.
Deciduous
Green
Alternate
Lanceolate
Dentate
3-6 inches
Poisonous to Humans
Nausea, vomiting, diarrhea, salivation, exhaustion and weakness, dilation of pupils, convulsions, and coma
Alkaloids lobelamine, lobeline, and others, plus a volatile oil
Seeds
Leaves
Stems
Sap/Juice
Flowers
Fruits
Roots
Whole Plant Traits
Perennial
Native Plant
Poisonous
Wildflower
Herb
Deciduous
Low
Cultural Conditions
Full sun (6 or more hours of direct sunlight a day)
Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Deep shade (Less than 2 hours to no direct sunlight)
Moist
Occasionally Wet
Mountains
Piedmont
4a
4b
5b
5a
6a
6b
7a
7b
8b
8a
9a
9b
High Organic Matter
Stem
Landscape
Butterfly Garden
Pollinator Garden
Rain Garden
Native Garden
Border
Deer
Wet Soil
Woodland
Meadow
Naturalized Area
Riparian
Butterflies
Pollinators
Hummingbirds
Poisonous to Humans
Lobelia siphilitica Image Gallery
Lobelia siphilitica Attributes
Lobelia siphilitica: Wildlife Value
Its flowers are attractive to hummingbirds and butterflies.
Lobelia siphilitica: Particularly Resistant To (Insects/Diseases/Other Problems)
This plant has low resistance to damage from deer.
Lobelia siphilitica: Life Cycle
Annual
Biennial
Bulb
Perennial
Woody
Lobelia siphilitica: Recommended Propagation Strategy
Division
Grafting
Layering
Leaf Cutting
Root Cutting
Seed
Stem Cutting
Lobelia siphilitica: Play Value
Attractive Flowers
Attracts Pollinators
Buffer
Colorful
Defines Paths
Easy to Grow
Edible fruit
Fragrance
Pieces Used in Games
Screening
Shade
Sound
Textural
Wildlife Cover/Habitat
Wildlife Food Source
Wildlife Larval Host
Wildlife Nesting
Wind Break
Wind Shimmer
Lobelia siphilitica: Fire Risk Rating
extreme flammability
high flammability
low flammability
medium flammability
Lobelia siphilitica Fruit
Lobelia siphilitica: Fruit Description
Displays from August to November
Lobelia siphilitica: Display/Harvest Time
Fall
Spring
Summer
Winter
Lobelia siphilitica Flowers
Lobelia siphilitica: Flower Description
Great lobelia is a clump-forming perennial which features an elongated cluster of light to dark blue, tubular, 2-lipped flowers with the three lobes of the lower lip appearing more prominent than the two lobes of the upper lip. The flowers arise from the upper leaf axils forming a dense terminal raceme atop stiff, unbranched, leafy stalks typically rising 2-3' tall. Its flowers are larger than other lobelias and have stripes on the tube portion. Blooms from July to October.
Lobelia siphilitica: Flower Color
Blue
Lobelia siphilitica: Flower Inflorescence
Catkin
Corymb
Cyme
Head
Insignificant
Panicle
Raceme
Solitary
Spadix
Spike
Umbel
Lobelia siphilitica: Flower Value To Gardener
Edible
Fragrant
Good Cut
Good Dried
Long Bloom Season
Long-lasting
Showy
Lobelia siphilitica: Flower Bloom Time
Winter
Spring
Summer
Fall
Lobelia siphilitica: Flower Shape
Bell
Cross
Crown
Cup
Dome
Funnel
Irregular
Lipped
Radial
Saucer
Star
Trumpet
Tubular
Urn
Wheel
Lobelia siphilitica Leaves
Lobelia siphilitica: Leaf Description
Great lobelia has finely-toothed, lance-shaped, light green leaves (to 5" long). The alternate, stalkless leaves are 2 to 6 inches long.
Lobelia siphilitica: Woody Plant Leaf Characteristics
Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen
Lobelia siphilitica: Leaf Color
Green
Lobelia siphilitica: Leaf Arrangement
Alternate
Opposite
Other/more complex
Rosulate
Whorled
Lobelia siphilitica: 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
Lobelia siphilitica: Leaf Margin
Crenate
Crenulate
Dentate
Denticulate
Doubly Crenate
Doubly Dentate
Doubly Serrate
Entire
Lobed
Serrate
Sinuate
Undulate
Lobelia siphilitica: Hairs Present
No
Yes
Lobelia siphilitica: Leaf Length
< 1 inch
1-3 inches
3-6 inches
> 6 inches
Lobelia siphilitica Poisonous to Humans
Lobelia siphilitica: Poison Symptoms
Nausea, vomiting, diarrhea, salivation, exhaustion and weakness, dilation of pupils, convulsions, and coma
Lobelia siphilitica: Poison Toxic Principle
Alkaloids lobelamine, lobeline, and others, plus a volatile oil
Lobelia siphilitica: Poison Severity
High
Low
Medium
Lobelia siphilitica: Causes Contact Dermatitis
No
Yes
Lobelia siphilitica: Poison Part
Bark
Flowers
Fruits
Leaves
Roots
Sap/Juice
Seeds
Stems
Lobelia siphilitica Whole Plant Traits
Lobelia siphilitica: 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
Lobelia siphilitica: Woody Plant Leaf Characteristics
Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen
Lobelia siphilitica: Maintenance
Low
Medium
High
Lobelia siphilitica Cultural Conditions
Lobelia siphilitica: 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)
Lobelia siphilitica: Soil Drainage
Frequent Standing Water
Good Drainage
Moist
Occasional Flooding
Occasionally Dry
Occasionally Wet
Very Dry
Lobelia siphilitica: NC Region
Coastal
Mountains
Piedmont
Lobelia siphilitica: USDA Plant Hardiness Zone
4a
4b
5a
5b
6a
6b
7a
7b
8a
8b
9a
9b
Lobelia siphilitica: Soil Texture
Clay
High Organic Matter
Loam (Silt)
Sand
Shallow Rocky
Lobelia siphilitica Stem
Lobelia siphilitica: Stem Is Aromatic
No
Yes
Lobelia siphilitica Landscape
Lobelia siphilitica: 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
Lobelia siphilitica: 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
Lobelia siphilitica: 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
Lobelia siphilitica: 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
Lobelia siphilitica: Attracts
Bats
Bees
Butterflies
Frogs
Hummingbirds
Moths
Pollinators
Predatory Insects
Reptiles
Small Mammals
Songbirds
Specialized Bees
Lobelia siphilitica: Problems
Allelopathic
Contact Dermatitis
Frequent Disease Problems
Frequent Insect Problems
Invasive Species
Malodorous
Messy
Poisonous to Humans
Problem for Cats
Problem for Children
Problem for Dogs
Problem for Horses
Short-lived
Spines/Thorns
Weak Wood
Weedy
