Cliff Mining Bee vs Coastal Arrowhead

Andrena thoracica compared with Sagittaria graminea

Key Differences

Cliff Mining Bee is Extinct while Coastal Arrowhead is Not Evaluated.

Taxonomic Classification

Rank	Cliff Mining Bee	Coastal Arrowhead
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Liliopsida (Monocots)
Order	Hymenoptera (Ants, Bees & Wasps)	Alismatales (Alismatales)
Family	Andrenidae	Alismataceae
Genus	Andrena	Sagittaria
Species	Andrena thoracica	Sagittaria graminea

Conservation Status

Cliff Mining Bee

EX — Extinct

Coastal Arrowhead

NE — Not Evaluated

Physical Characteristics

Attribute	Cliff Mining Bee	Coastal Arrowhead
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cliff Mining Bee

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Denmark, Luxembourg, Norway, and Sweden.

Coastal Arrowhead

Habitat

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

Range

Widely distributed across Asia (China, Japan), Europe (6 countries), and North America (United States).

Cliff Mining Bee

The Cliff Mining Bee, Andrena species in the family Andrenidae, is a solitary ground-nesting bee that excavates tunnels in cliff faces, earthen banks, and compacted sandy or loamy soils, where the loose or friable substrates exposed in cliff profiles provide ideal nesting conditions. Mining bees in the genus Andrena are among the most species-rich solitary bee genera in the world, with hundreds of species across the Holarctic region, many narrowly specialized in their choice of pollen host plants. Female cliff mining bees construct vertical or angled burrows in cliff faces, with lateral cells off the main shaft, each containing a pollen ball and a single egg. Males are typically smaller and emerge before females to establish territories near nesting sites. Many Andrena species are oligolectic, collecting pollen from only a small number of plant species, making their populations sensitive to the availability of specific flowering plants in the landscape surrounding nesting areas. Cliff and bank nesting habitats provide well-drained, sun-warmed substrates essential for brood development. The loss of natural cliff faces and earthen banks to development, vegetation succession, and quarrying reduces available nesting habitat for cliff mining bees.

Coastal Arrowhead

Sagittaria graminea, the coastal arrowhead or grass-leaved arrowhead, is an aquatic or semi-aquatic perennial herb in the family Alismataceae native to wetland habitats across a wide geographic range including eastern North America, parts of Asia including China and Japan, and isolated populations in Europe. The species inhabits shallow water margins, muddy shores, freshwater marshes, slow-moving streams, ditches, and pond edges, where it often forms dense emergent colonies. Sagittaria graminea is distinguished from other arrowheads by its narrow, grass-like submerged and emergent leaves that lack the pronounced arrowhead shape characteristic of the genus when leaves are fully emergent, though aerial leaves may have small basal lobes. The plant produces white three-petaled flowers arranged in whorls on tall flowering stems, with male flowers above and female flowers below. It is assessed as Not Evaluated by the IUCN. The tubers of arrowheads have historically been consumed as a starchy food by Indigenous peoples across North America. The species provides important habitat structure for aquatic invertebrates and waterfowl, and waterfowl consume the seeds and tubers. The name Sagittaria derives from the Latin for arrow, reflecting the classic arrowhead leaf shape seen in other species of the genus.