Blue star vs

Amsonia orientalis compared with Chrysosphaerella annulata

Key Differences

• Blue star is Critically Endangered while is Not Evaluated.

Taxonomic Classification

Rank	Blue star
Kingdom	Plantae (Plants)	Chromista (Chromista)
Phylum	Magnoliophyta (Flowering Plants)	Ochrophyta (Ochrophyta)
Class	Magnoliopsida (Dicots)	Chrysophyceae (Chrysophyceae)
Order	Gentianales (Gentianales)	Ochromonadales (Ochromonadales)
Family	Apocynaceae	Paraphysomonadaceae
Genus	Amsonia	Chrysosphaerella
Species	Amsonia orientalis	Chrysosphaerella annulata

Conservation Status

Blue star

CR — Critically Endangered

NE — Not Evaluated

Physical Characteristics

Attribute	Blue star
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Blue star

Habitat

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

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Blue star

The Blue star (Amsonia orientalis) is a species in the genus Amsonia. It is currently classified as Critically Endangered on the IUCN Red List. Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Chrysosphaerella annulata is a colonial freshwater chrysophyte microalga in the genus Chrysosphaerella, class Chrysophyceae. Unlike unicellular loricate chrysophytes, Chrysosphaerella species form spherical or ellipsoidal free-floating colonies in which individual cells are embedded in a common gelatinous matrix. The individual cells bear long siliceous scales with distinctive ring-like or annular structures — referenced by the species epithet annulata — projecting outward from the colony surface, giving the colony a spiny appearance under microscopy. These siliceous scales are species-specific and their morphology, as revealed through electron microscopy, is the primary character for identifying Chrysosphaerella species. C. annulata has been recorded from Norwegian and Swedish freshwater environments, consistent with the Scandinavian emphasis in chrysophyte research and the high diversity of chrysophytes in boreal freshwater systems. Chrysosphaerella colonies are planktonic, inhabiting the limnetic zone of oligotrophic to mesotrophic lakes where they may form locally conspicuous populations during favorable conditions. The species uses chlorophylls a and c with fucoxanthin for photosynthesis, contributing to primary production. Chrysosphaerella scales can accumulate in lake sediments, providing a record of past community composition and environmental conditions. C. annulata has not been assessed under IUCN criteria and is classified as Not Evaluated. Its documentation contributes to understanding the diversity of colonial chrysophyte forms in northern European freshwater ecosystems.