Common Crabgrass vs Laysan Duck

Digitaria ciliaris compared with Anas laysanensis

Key Differences

Common Crabgrass is Not Evaluated while Laysan Duck is Critically Endangered.

Taxonomic Classification

Rank	Common Crabgrass	Laysan Duck
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Chordata (Chordates)
Class	Liliopsida (Monocots)	Aves (Birds)
Order	Poales (Grasses)	Anseriformes (Anseriformes)
Family	Poaceae (Grass Family)	Anatidae
Genus	Digitaria	Anas
Species	Digitaria ciliaris	Anas laysanensis

Conservation Status

Common Crabgrass

NE — Not Evaluated

Laysan Duck

CR — Critically Endangered

Physical Characteristics

Attribute	Common Crabgrass	Laysan Duck
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Crabgrass

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Widely distributed across Africa (8 countries), Asia (8 countries), Europe (18 countries), North America (10 countries), Oceania and the Pacific (12 countries), and South America (5 countries).

Laysan Duck

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Belgium, France, Netherlands, Norway, and United Kingdom. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Crabgrass

<em>Digitaria ciliaris</em>, commonly known as common crabgrass or southern crabgrass, is an annual grass in the family Poaceae. It has a near-cosmopolitan distribution, occurring across tropical, subtropical, and warm temperate regions on multiple continents. This species typically colonizes disturbed habitats including lawns, gardens, roadsides, cultivated fields, and waste ground, making it one of the most widespread grass weeds in the world. Common crabgrass spreads rapidly via its sprawling, branching stems that root at the nodes when they contact moist soil. It produces slender, finger-like racemes bearing small, paired spikelets. The species thrives in warm weather and full sun, declining with the onset of cooler autumn temperatures. While it is considered a troublesome weed in many agricultural and horticultural contexts, it also provides ground cover and food for various seed-eating birds. Biological traits of this species remain poorly documented in the scientific literature.

Laysan Duck

Laysan Duck (Anas laysanensis) is classified as Critically Endangered (CR) on the IUCN Red List. Facing an extremely high risk of extinction in the wild due to severe population decline and habitat loss.