vs Common corncockle

Cocconeis placentula compared with Agrostemma githago

Key Differences

is Not Evaluated while Common corncockle is Critically Endangered.

Taxonomic Classification

Rank		Common corncockle
Kingdom	Chromista (โครมิสตา)	Plantae (พืช)
Phylum	Ochrophyta (Ochrophyta)	Magnoliophyta (Flowering Plants)
Class	Bacillariophyceae (Bacillariophyceae)	Magnoliopsida (พืชใบเลี้ยงคู่)
Order	Achnanthales (Achnanthales)	Caryophyllales (อันดับคาร์เนชัน)
Family	Cocconeidaceae	Caryophyllaceae
Genus	Cocconeis	Agrostemma
Species	Cocconeis placentula	Agrostemma githago

Conservation Status

NE — Not Evaluated

Common corncockle

CR — Critically Endangered

Physical Characteristics

Attribute		Common corncockle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Asia and Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, Portugal, Sweden, and Taiwan.

Common corncockle

Habitat

Found across multiple habitat types including montane grasslands and shrublands, tropical and subtropical moist broadleaf forests, and temperate coniferous forests, among 13 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Lesotho), Asia (7 countries), Europe (24 countries), North America (Canada, Mexico, United States), Oceania and the Pacific (Australia), and South America (Brazil, Chile). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Cocconeis placentula is among the most ubiquitous and widely studied freshwater and brackish-water diatoms worldwide, serving as a model organism for periphyton ecology and a key species in biological assessment of water quality. A member of the family Cocconeidaceae, this adnate epiphyte produces a characteristic ovoid frustule with fine transapical striae, a well-developed raphe system on one valve, and an elaborate pattern of areolae visible under electron microscopy. The species complex encompasses several morphological varieties (var. placentula, var. lineata, var. euglypta, var. acuta) that differ in fine structural details of the valve ornamentation. Cocconeis placentula colonizes the surfaces of aquatic plants, algae, rocks, and sediment particles in rivers, lakes, and ponds across a vast global range spanning Europe, the Americas, Asia, Africa, and beyond, tolerating a wide range of water temperatures, pH values, and moderate nutrient enrichment. Its abundance varies dramatically with substrate type, light availability, and water chemistry, making community composition data involving this species valuable in diatom-based paleolimnological reconstructions and modern bioassessment indices. As a benthic primary producer, C. placentula contributes substantially to the productivity of the photic benthos and serves as a dietary component for invertebrate grazers. Its remarkable cosmopolitan distribution and ecological flexibility make it one of the defining species of freshwater periphyton communities globally. Conservation status is not formally assessed.

Common corncockle

<em>Agrostemma githago</em>, commonly known as common corncockle, is an annual flowering plant in the family Caryophyllaceae. Once a widespread weed of cereal crops across Europe, Asia, and beyond, this species is now Critically Endangered on the IUCN Red List due to the dramatic decline caused by modern agricultural practices, particularly improved grain cleaning and herbicide use. Corncockle is a tall, slender plant covered in silky white hairs, bearing large, solitary pink to purple flowers with distinctive dark veining. Its seeds contain toxic saponin compounds called githagins, which historically contaminated grain supplies. The species now survives primarily in wildflower conservation areas, seed banks, and traditional farmland conservation schemes. It typically grows in open, disturbed arable soils with full sun exposure. Biological traits of this species remain poorly documented in the scientific literature.