Blackboard Tree vs Coast Indigo

Alstonia scholaris compared with Indigofera miniata

Taxonomic Classification

Rank	Blackboard Tree	Coast Indigo
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Magnoliopsida (Dicots)	Magnoliopsida (Dicots)
Order	Gentianales (Gentianales)	Fabales (Legumes & Allies)
Family	Apocynaceae	Fabaceae
Genus	Alstonia	Indigofera
Species	Alstonia scholaris	Indigofera miniata

Evolutionary Relationship

Blackboard Tree and Coast Indigo share a common ancestor at the Class level: Magnoliopsida. (Dicots)

Conservation Status

Blackboard Tree

LC — Least Concern

Coast Indigo

LC — Least Concern

Physical Characteristics

Attribute	Blackboard Tree	Coast Indigo
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Blackboard Tree

Habitat

Inhabits tropical and subtropical moist broadleaf forests and tropical and subtropical dry broadleaf forests within the Oceanian biogeographic realm.

Range

Distributed across Micronesia, Taiwan, and United States.

Coast Indigo

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Found in Cuba.

Blackboard Tree

The Blackboard Tree (Alstonia scholaris) is a species in the genus Alstonia. It is currently classified as Least Concern on the IUCN Red List. Inhabits tropical and subtropical moist broadleaf forests and tropical and subtropical dry broadleaf forests within the Oceanian biogeographic realm.

Coast Indigo

Coast indigo (Indigofera miniata) is a perennial herb or subshrub in the family Fabaceae, native to the coastal scrub, pine barrens, and sandy grasslands of Cuba and the broader Caribbean region. Like other members of the genus Indigofera, it produces compound pinnate leaves and racemes of small, pea-type flowers, though in this species the flowers are notably small and pinkish to reddish. The genus Indigofera is best known for Indigofera tinctoria, the source of natural indigo dye, but most species including Indigofera miniata have not been commercially exploited for dye production. Coast indigo grows in open, sunny, often disturbed habitats including sandy coastal plains, roadsides, and degraded scrubland, benefiting from its ability to fix atmospheric nitrogen through root nodule bacteria—a common trait in the legume family. The IUCN assesses it as Least Concern, reflecting its ability to persist in disturbed and marginal coastal habitats across the Caribbean. Regional populations are affected by coastal development and vegetation clearance but are not considered globally threatened.