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Thalia geniculata (red-stemmed)


Thalia geniculata (red-stemmed)

Family Name: Marantaceae
Synonyms: Thalia geniculata f. rheumoides
Common Name: Red Thalia, Red-stemmed Alligator Flag


Family Name
Genus Epithet
Species Epithet
Infraspecific Epithet
Name Status (botanical)
Common Names

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Monocotyledon)
Plant Growth Form Aquatic & Hydrophyte (Emergent), Herbaceous Plant
Lifespan (in Singapore) Perennial
Mode of Nutrition Autotrophic
Plant Shape Shrubby
Maximum Height 2.4 m to 3 m
Maximum Plant Spread / Crown Width 0.6 m to 0.9 m


Native Distribution Florida, Central America (West Indies)
Native Habitat Terrestrial (Riverine)
Preferred Climate Zone Tropical

Description and Ethnobotany

Others - Plant Morphology Marginal or emergent aquatic shrub, herbaceous, up to 3m height. Ideal for boggy waterlogged areas, pond edges and shallow water (15cm depth).Leaves lime-green, architectural. Flowers lavender and white, held in clusters of zigzag stalks high above foliage, stalks become more pendulous with successive blooms. Stems intense solid red or striped with red, ornamental. Propagate by division or seeds. Its common name, Alligator Flag, may be due to plant's native habitat at deeper waters of cypress swamps, where alligators are likely to be found.
Taxonomy In the horticultural trade, this plant is sometimes referred to as Thalia geniculata f. ruminoides.

Landscaping Features

Desirable Plant Features Ornamental Flowers, Ornamental Stems
Landscape Uses Riverine, Flowerbed / Border, Swimming Poolside, Focal Plant, Container Planting
Thematic Landscaping Water Garden, Naturalistic Garden
SGMP Treatment

Fauna, Pollination and Dispersal

Pollination Method(s) Biotic (Fauna) (Insects (Bee), Associated with: Carpenter bees (Xylocopa spp. ) are reported to pollinate T. geniculata in Costa Rica.)
Seed or Spore Dispersal Abiotic (Water), Biotic (Fauna)

Plant Care and Propagation

Light Preference Full Sun, Semi-Shade
Water Preference Lots of Water
Plant Growth Rate Fast to Moderate
Rootzone Tolerance Easy to Grow, Waterlogged Soils (Drains Site)
Maintenance Requirements Moderate
Propagation Method Seed, Division


Foliage Retention Evergreen
Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Smooth
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Basal
Foliar Shape(s) Non-Palm Foliage (Ovate)
Foliar Venation Parallel
Foliar Margin Entire
Foliar Apex - Tip Acuminate
Foliar Base Rounded / Obtuse
Typical Foliar Area Notophyll ( 20.25cm2 - 45 cm2 )

Non - Foliar and Storage

Stem Type & Modification Herbaceous
Root Type Underground (Fibrous Root)
Specialised Storage Organ(s) Underground (Rhizome)

Floral (Angiosperm)

Flower & Plant Sexuality Bisexual Flowers
Flower Colour(s) Purple, White
Flowering Period Free-Flowering
Flowering Opening Time Time-Independent
Flower Lifespan on Plant Several Days
Flowering Habit Polycarpic

Image Repository



Master ID 21764
Species ID 3373
Flora Disclaimer The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. It is not a substitute for medical advice or treatment and NParks does not purport to provide any medical advice. Readers should always consult his/her physician before using or consuming a plant for medicinal purposes.
Species record last updated on: 06 March 2023.