FNPS Plant Database

Bacopa caroliniana

blue waterhyssop, lemon hyssop

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Nomenclature

Common Name:

blue waterhyssop, lemon hyssop

Synonym(s):

Genus species:

Bacopa caroliniana

Family:

Plantaginaceae

Plant Specifics

Form:

flower

Size:

0.25-0.5 ft tall by extensive mats ft wide 

Life Span:

Short-lived perennial

Flower Color:

blue

Fruit Color:

Phenology:

winter dormant

Noted For:

Showy Flowers, Aroma

Landscaping

Recommended Uses:

Spreading ground cover around the edges of retention ponds and aquatic gardens. Groundcover in restoration areas. Also used in aquariums.

Considerations:

Availability:

Native Plant Nurseries

Propagation:

Easily roots from division or stem cuttings.

Light:

Full Sun

Moisture Tolerance:

Always Flooded------------------------------------------------Extremely Dry

<-> |----|----|----|----|----|----|----|----|----|----|----|----|-

Aquatic ---to--- Aquatic

Salt Water Flooding Tolerance:

Not salt tolerant of inundation by salty or brackish water.

Salt Spray/Salty Soil Tolerance:

Low/no tolerance of salty wind or direct salt spray

Soil or Other Substrate:

Sand

Soil pH:

broadly tolerant, prefers some organics

Suitable to Grow In:

8A, 8B, 9A, 9B, 10A, 10B

USDA zones are based on the average annual extreme minimum winter temperature.



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Ecology

Wildlife:

Pollinators, Caterpillars, Bees

Larval host plant for white peacock (Anartia jatrophae) butterflies. Insect pollinated.

Native Habitats:

Marshes, swamps, ditches

Natural Range in Florida:

Comments:

Ethnobotany:

Over the centuries, this plant has been used in religious and medical contexts. The plant has a broad distribution including a long history of ethnobotanical uses in India, leading to the suspicion that it may not be native to North America.

General Comments:

Lemon bacopa is distinguished by blue flowers, a hairy upper stem, and by the lemony scent of its crushed foliage. 

Citations:

Huegel, Craig N. 2012. Native Wildflowers and Other Ground Covers for Florida Landscapes. University Press of Florida, Gainesville.


Nelson, Gil. 2003. Florida's Best Landscape Plants: 200 Readily Available Species for Homeowners and Professionals. University Press of Florida, Gainesville.


Patton, Sean, and Kendall Southworth. 2025. Florida's Aquatic Butterfly Gardens: How to Create a Beautiful Backyard Habitat for Attracting 70+ Species with 100+ Native Plants. Pineapple Press, Palm Beach.

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