Blackboard Tree vs

Alstonia scholaris compared with Chrysococcus cordiformis

Key Differences

• Blackboard Tree is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Blackboard Tree
Kingdom	Plantae (Plants)	Chromista (Chromista)
Phylum	Magnoliophyta (Flowering Plants)	Ochrophyta (Ochrophyta)
Class	Magnoliopsida (Dicots)	Chrysophyceae (Chrysophyceae)
Order	Gentianales (Gentianales)	Chromulinales (Chromulinales)
Family	Apocynaceae	Dinobryaceae
Genus	Alstonia	Chrysococcus
Species	Alstonia scholaris	Chrysococcus cordiformis

Conservation Status

Blackboard Tree

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Blackboard Tree
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.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

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.

Chrysococcus cordiformis is a freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae. The species epithet cordiformis — heart-shaped — describes the characteristic lorica shape of this species, a lorica being the rigid or semi-rigid outer case secreted by the cell that gives Chrysococcus its distinctive appearance. The heart-shaped lorica of C. cordiformis provides a clear morphological character distinguishing it from species with spherical, ovoid, or otherwise shaped loricas. Chrysococcus species are unicellular, loricate golden algae that inhabit freshwater ecosystems, particularly the euphotic zones of oligotrophic to mesotrophic lakes and ponds. C. cordiformis has been documented from Norwegian and Swedish freshwater environments, which provide cold, clear-water habitats typical of Scandinavian highland and boreal lakes. Records also extend to Brazil, indicating a wide geographic range consistent with the passive dispersal capacity of small, light-weight planktonic microalgae. The cells of C. cordiformis possess one or two flagella that protrude through an opening in the lorica, enabling active swimming in the water column. Photosynthesis is conducted using chlorophylls a and c with carotenoid accessory pigments. Chrysococcus species may also feed phagotrophically on bacteria. C. cordiformis has not been formally evaluated under IUCN criteria and retains a conservation status of Not Evaluated. It represents a characteristic member of freshwater chrysophyte communities associated with cool, acidic, or nutrient-poor Scandinavian lake systems.