Sea-grasses

Common Neptune-grass Common Neptune-grass Dwarf Eelgrass Common Eelgrass



Neptune-grasses - Posidoniaceae

Common Neptune-grass      Posidonia oceanica

Native throughout the Mediterranean Region. A submarine, flowering plant that forms extensive colonies on the seabed but typically is only seen when plant fragments are washed ashore. Vast quantities of old leaf fragments wash up on beaches regularly, often being rolled up into tight balls, known locally as egagropili or 'Neptune's Balls'.

Common Neptune-grass Common Neptune-grass Common Neptune-grass Common Neptune-grass
Leaf fragments
'Neptune's Balls'
'Neptune's Balls'
Leaf bases and stem
Common Neptune-grass Common Neptune-grass Common Neptune-grass Common Neptune-grass
Leaf bases and stem
Washed up leaves
Fruit
Fruit


Eelgrasses - Zosteraceae

Common Eelgrass      Zostera marina

Native throughout coastal waters of the Atlantic and Pacific Oceans and the Mediterranean and Black Seas. A submarine, flowering plant that forms colonies on the seabed in inshore areas, typically just at the lowest low tide zone. Leaves 1-10mm wide. Flowers enclosed within a leaf sheath.

Common Eelgrass Common Eelgrass Common Eelgrass Common Eelgrass
Submerged plants
Submerged plants
Plant fragments
Plant fragments
Common Eelgrass Common Eelgrass Common Eelgrass Common Eelgrass
Leaves
Flower spike
Flower spike
Flower spike


Dwarf Eelgrass      Zostera noltii

Native throughout coastal waters of Europe and the Mediterranean Region, eastwards to the Caspian Sea. A submarine, flowering plant that forms colonies on the seabed in inshore areas, typically just at the lowest low tide zone. Leaves 0.5-1.5mm wide. Flowers separate from leaf sheaths.

Dwarf Eelgrass Dwarf Eelgrass
Exposed plants at low tide
Submerged plants
Dwarf Eelgrass Dwarf Eelgrass Dwarf Eelgrass
Leaves
Leaves
Flower spike


Pondweeds - Potamogetonaceae

Horned Pondweed      Zannichellia palustris

Native throughout temperate and warm temperate regions of the World. In lower reaches of rivers and in fresh and brackish water. Most readily told from other pondweeds by its mostly opposite leaves and its small clusters of flowers that are carried close to the stem rather than on long stalks. Fruits with a distinct, spike-like beak, longer than that typically found on other pondweeds and giving the species its English name.

Horned Pondweed Horned Pondweed Horned Pondweed Horned Pondweed
Habit
Leaf detail
Leaves and fruits
Fruit


Tasselweeds - Ruppiaceae

Beaked Tasselweed      Ruppia maritima

(Wigeongrass) Native throughout much of the World. In saltmarsh pools and brackish pools inland in high salt areas. Best told from the other pondweeds by its mostly alternate lower leaves and opposite upper leaves and its small clusters of flowers that are carried close to the stem at first, but which then elongate greatly as the fruits develop. The fruits thus appear singlely at the ends of long stalks, rather than in a tight cluster. Leaves have a midrib but no side veins.

Beaked Tasselweed Beaked Tasselweed Beaked Tasselweed Beaked Tasselweed
Habit
Habit
Habit
Flower spikes
Beaked Tasselweed Beaked Tasselweed Beaked Tasselweed Beaked Tasselweed
Early flower spike
Flowering spike
Developing fruits
Developing fruits