Funastrum clausum
 
Common Names White Twinevine, Sarcostemma, Milkweed Vine
 
Zones 9B–11
 
A vigorous, twining vine native to South Florida, the Caribbean, and tropical Americas, Funastrum clausum is a member of the milkweed family (Apocynaceae) and a vital larval host for monarch, queen, and soldier butterflies. Its fragrant white flowers bloom in umbels throughout the year, offering nectar to a wide range of pollinators. Though beautiful, it is extremely aggressive and best suited for large-scale restoration, trellised wildlife gardens, or containment in controlled landscapes2.
 
Key Features
Growth Habit: Twining vine; climbs by wrapping stems; forms dense mats
Length: 20–30 ft (6–9 m) or more
Leaves: Opposite; linear to oblong; dark green; semi-succulent
Flowers: White with purple centers; borne in umbels; fragrant; bloom year-round, peak in summer/fall
Fruit: Erect follicles; split open to release wind-dispersed seeds with silky pappus
Ecology: Native to wetland edges, hammocks, and coastal strands; larval host for Danaus plexippus, D. gilippus, and D. eresimus2
 
Growing Conditions
Light: Full sun to part shade
Watering: Moderate; prefers moist soils, tolerates occasional inundation
Soil: Alkaline to mildly acidic; sandy, loamy, or organic-rich
Temperature: Frost sensitive; protect below 35°F (1.6°C)
Humidity: High tolerance; thrives in subtropical climates
Propagation: Seed or cuttings
Tolerance: Low salt tolerance; not suitable for direct coastal exposure
 
Landscape Use Best for butterfly gardens, wetland restoration, and trellised wildlife corridors. Use with caution in small gardens due to aggressive growth. Pairs well with Passiflora suberosa, Ipomoea microdactyla, and Asclepias perennis.