Rolf Nussbaumer / Flower head of Rattlesnake flower (Brazoria truncata) Fennessey Ranch, Refugio, Coastal Bend, Texas Coast, USA

Rolf Nussbaumer / Close up of Rattlesnake flower (Brazoria truncata)Fennessey Ranch, Refugio, Coastal Bend, Texas Coast, USA

Wild Wonders of Europe / Lilja / Flowering Henbit deadnettle (Lamium amplexicaule) and Poppy anemone (Anemone coronaria) covered in raindrops, Omalos, Crete, Greece, April 2009

Dietmar Nill / Bumblebee flies from Lamium flower (Spotted deadnettle) Germany

Nigel Cattlin / White dead-nettle (Lamium album) seedling with two cotyledons and two true leaves. A garden and arable agricultural weed.

Ernie Janes / Bluebells (Hyacinthoides non-scripta) and Yellow Archangel (Lamium galeobdolon) Blickling Great Wood, Norfolk, England, UK, May.

Ernie Janes / Bluebells (Hyacinthoides non-scripta) and Yellow Archangel (Lamium galeobdolon) Blickling Great Wood, Norfolk, England, UK, May.

Heather Angel / White dead nettle (Lamium album) with stamens protected from rain by overhanging upper lip. Pollinated by bumblebees. Naturalised in garden, Surrey, England, UK. May.

Ernie Janes / Ramsons (Allium ursinum) growing among Yellow Archangel (Lamium galeobdolon) in woodland, Norfolk, England, UK, May.

Gary K. Smith / White nettle (Lamium album) on white background.

Fabrice Cahez / Yellow archangel (Lamiastrum galeobdolon) close up of flower, Vosges, France, May.

Nick Upton / Red dead nettle (Lamium purpureum) flowering on a retaining wall, Bath, UK, March.