Black-eyed Susan Vine – Detail Page

Black-eyed Susans Thunbergia alata are the national flower of Saba  Photo credit Christian König: SHAPE/DCNA

English Name: Black-eyed Susan Vine

Scientific Name: Thunbergia alata

Kingdom: Plantae

Phylum: Anthophyta

Class: Dicotyledoneae

Order: Scrophulariales

Family: Acanthaceae (Flowering plants)

Genus: Thunbergia

Other Names: 


Conservation Status: 

  • IUCN Red List: not yet assessed.
  • CITES: not listed.
  • SPAW: not listed.

Island Status:

  • One of Saba’s most common plants; it can be found all over the island.


Black-eyed Susan grows to a height of 1.8 to 2.4 m (~5.9 to 7.9 ft). The vine has twining stems with bright green leaves that are either heart-shaped or arrow-shaped. The flower is typically yellow to warm orange with a black center. It has five petals. The brown fruit is small and looks like the head of a bird, with its rounded based and elongated beak.

Distinct features: 1) the bright green leaves are quite coarse and hairy; and 2) the beautiful flower is hard to miss; it is typically bright yellow but it can also be white, orange or red.

Life History

The Black-eyed Susan vine is a perennial, meaning that it will typically live for more than two years. It is pollinated by bees, which carry the pollen to another flower. It is believed that seeds are ejected when the vine’s fruit opens.

Habitat: Tropical evergreen forest.

Distribution: Native to tropical Africa. It is now found in several parts of the world including Saba, Brazil, Hawaii and southern USA.

Local Research and Conservation Efforts

The Black-eyed Susan Vine is protected within the Saba Terrestrial Park.

Did You Know?

  • The beautiful flower of the Black-eyed Susan Vine is the national flower of Saba.
  • The Black-eyed Susan vine originates from South Africa, and it is believed that is was introduced to the island by the Dutch when the island was colonized.
  • The name ‘Black-eyed Susan’ is named after the vine’s flower’s distinct dark-brown center.

Related Pages:
Species in the Spotlight: Black-eyed Susan Vine