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Stachytarpheta mutabilis


Stachytarpheta mutabilis (Jacq.) Vahl

Family Name: Verbenaceae
Synonyms: Verbena mutabilis
Common Name: Changeable Velvetberry, Red Porterweed, Pink Snakeweed, Pink False Vervain, Pink Rat Tail


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

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Dicotyledon)
Plant Growth Form Shrub
Lifespan (in Singapore) Perennial
Mode of Nutrition Autotrophic
Plant Shape Rounded
Maximum Height 1.2 m to 1.8 m


Native Distribution Mexico, Caribbean, South America
Native Habitat Terrestrial (Disturbed Area / Open Ground)
Preferred Climate Zone Tropical
Local Conservation Status Non-native (Spontaneous (Casual))

Description and Ethnobotany

Growth Form A woody shrub with long prominent spike inflorescences. 
Foliage Opposite leaves are elliptic to ovate (5 - 12 cm long, 2.5 - 6 cm wide). The leaf margin is serrate or crenate, having teeth that point towards the leaf tip. Leaves are deeply veined, giving the upper surface a rugose, uneven texture. The lower surface is covered in soft, short hairs. Leaves are acute (pointed, but indistinct tip) or acuminate (thin, distinct pointed tip). 
Stems Woody stem has light grey bark. Young stems are 4-sided and covered in soft, short hairs.
Flowers Salverform flowers have a white throat and 5 lobes (1.3 - 1.8 cm long, 1 cm wide). Initially bright red or magenta, they gradually become light pink over a few days. They are arranged on a 10 - 60 cm long terminal spike inflorescence (an inflorescence at the stem tip which has stalkless flowers held along one main axis). About 5 - 7 flowers are open at a time on the spike. They last for several days before being replaced by a new set. The inflorescence blooms in this manner for months. 
Fruits Dry, indehiscent fruit is known as a nutlet, a one-seeded small nutlike fruit. It is formed by the fragmentation of a multi-sectioned fruit into single-seeded pieces. 
Habitat Found in disturbed areas, such as along roadsides or in pastures that have been overgrazed. Also occurs along creeks, It is considered an invasive species in Australia, Hawaii, and the Fiji Islands. 
Cultivation Plant in well-drained, fertile soil enriched with compost. Space individuals 1.2 - 1.8 m apart. To prevent excessive establishment of new seedlings, remove spent flowers before they set seed. 
Etymology The genus "Stachytarpheta" comes from the Greek words for spike ("stachys") and thick ("tarphys"). It refers to the spike inflorescence found in many species of this genus. The species epithet "mutabilis" means that it has the ability to change. This refers to how the flowers change colour from reddish to pink over time.

Landscaping Features

Landscaping This species is planted as an ornamental shrub for its pinkish flowers. The flowers are interesting in that their colour gradually fades from reddish to light pink. This species is ideal for butterfly gardens as a nectar plant. Place it in the back to avoid obscuring smaller species. It may also be planted as a living fence or hedge. 
Desirable Plant Features Ornamental Flowers
Plant & Rootzone Preference - Tolerance Fertile Loamy Soils, Well-Drained Soils
Landscape Uses General, Hedge / Screening, Container Planting
Thematic Landscaping Butterfly Garden
Usage Hazard - Cons Invasive / Potentially Invasive

Fauna, Pollination and Dispersal

Fauna Pollination Dispersal Associated Fauna Butterfly Food Plant (Flower Nectar), Bee-Attracting
Pollination Method(s) Biotic (Fauna) (Insects (Butterfly, Moth))
Seed or Spore Dispersal Abiotic, Biotic (Fauna)

Plant Care and Propagation

Light Preference Full Sun
Water Preference Moderate Water
Planting Distance From 1
Planting Distance To 1
Maintenance Requirements Moderate
Propagation Method Seed, Stem Cutting (Softwood)
Propagation Method Remarks Propagate by seed or softwood cuttings. To collect seeds for propagation, allow the seedhead to dry on the plant before harvesting the seeds. 


Foliage Retention Evergreen
Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Raised / Sunken Veins
Prominent Young Flush Colour(s) Green
Young Flush Texture(s) Raised / Sunken Veins
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Opposite
Foliar Attachment to Stem Petiolate
Foliar Shape(s) Non-Palm Foliage (Ovate, Elliptical)
Foliar Venation Pinnate / Net
Foliar Margin Serrate / Toothed, Crenate
Foliar Apex - Tip Acute, Acuminate
Foliar Base Cuneate
Typical Foliar Area Mesophyll ( 45cm2 - 182.25 cm2 )

Non - Foliar and Storage

Bark Colour(s) Light grey
Stem Type & Modification Woody
Root Type Underground (Tap Root)

Floral (Angiosperm)

Flower & Plant Sexuality 1 Bisexual Flowers
Flower Colour(s) Pink, Red
Flower Grouping Cluster / Inflorescence
Flower Location Terminal
Flower Symmetry Bilateral
Individual Flower Shape Salverform
Flower Size - Remarks floral tube is 1.3 - 1. 8 cm long
Inflorescence Type Spike
Flower Transitional Changes Colour
Flowering Period Free-Flowering
Flowering Opening Time Daytime
Flower Lifespan on Plant Several Days
Flowering Habit Polycarpic

Fruit, Seed and Spore

Fruit Classification Simple Fruit
Fruit Type 1 Indehiscent Dry Fruit
Fruit Type 2 Nut / Nutlet

Image Repository



Master ID 29417
Species ID 3726
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: 20 August 2022.