Oriol Alamany / Spiti river and Dhar Chara Thang mountain sen from Malling in Spiti valley, Cold Desert Biosphere Reserve, Himalaya mountains, Himachal Pradesh, India, February

Willem Kolvoort / Ditch with Chara algae (Chara sp), North Holland. May.

Nick Upton / Delicate stonewort (Chara virgata) on the left without sporangia and on the right with sporangia. Red (male) antheridia and brown, flask shaped (female) archegonia, Marlborough Downs, Wiltshire, UK, S...

Nick Upton / Delicate stonewort (Chara virgata) on the left without sporangia and on the right with sporangia. Red (male) antheridia and brown, flask shaped (female) archegonia, Marlborough Downs, Wiltshire, UK, S...

Nick Upton / Week old Common frog tadpoles (Rana temporaria) grazing Delicate stonewort (Chara virgata) algae in a freshwater pond, Wiltshire, UK, June.

Nick Upton / Week old Common frog tadpole (Rana temporaria) grazing Delicate stonewort (Chara virgata) algae in a freshwater pond, Wiltshire, UK, June.

Nick Upton / Duck Leech (Theromyzon tessulatum) waiting and ready to crawl up the nostrils of a duck to suck blood from its respiratory tracts, reaching out from a Delicate stonewort (Chara virgata) alga in a shal...

Willem Kolvoort / Stonewort algae {Chara vulgaris} in freshwater lake, Lake Naarden, Holland

Willem Kolvoort / Stonewort algae {Chara vulgaris} with male fertilised cells, Lake Naarden, Holland

Willem Kolvoort / Stonewort algae {Chara vulgaris} Lake Naarden, Holland

Jean E. Roche / Pondweeds - orange (Chara) and (Callitriche sp.) oxygen production. Camargue, France, Europe