nfoto Posted July 15, 2014 Share Posted July 15, 2014 Rørslett, B. 2014. Cuscuta europaea L. (Convolvulaceae). Greater Dodder. Flowers photographed in visible and ultraviolet light. Cuscuta europaea L. (ssp. europaea)NO: Neslesniketråd; neslesnikjetrådSE: NässlesnärjaDK: Nælde-SilkeFI: HumalanvierasDE: Nessel-Seide EN: Greater Dodder This is a parasite entirely depending on its host(s) for all nutrients and water supply. Cuscuta has no chlorophyll on its own. The stem can be many metres long, is richly branched, and cover the host(s) with silk-like fine threads. Here and there the stems entwine with a series of tight coils and haustoria (suckers) penetrate the epidermis of the host to get nutrient supply. Depending on the race, the stems range from nearly white to deep red. The tiny flowers are borne in small, dense clusters. The nominal race (ssp. europaea) has four petals and white to yellow stems, the litoral race (ssp. halophyta) usually has red stems and flowers with five petals. In other aspects they are very similar. The vernacular names indicate C. europaea attack nettle (Urticaria dioica), but the nettle is just one out of a wide range of species that can be parasitized. When C. europea occurs in a meadow, all plants present are preyed upon, no matter what species they belong to. Thus, the specimen documented here had hosts such as grasses (Brachypodium pinnatum, Dactylites glomerata), and at least 15 widely different herbs. Image reference: CUSC_EUR_B407041602_VIS.jpgVisible light: Nikon D40X, Olympus OM 38 mm f/2.8 Zuiko, SB-21 ring flash, magnification m=2. The photographed section of the C. europaea plant preyed on Allium viennale (the Allium inflorescence is on the left hand side of the photo) and several grass species. Image reference: CUSC_EUR_14070419663_UV.jpgUltraviolet light: Nikon D40X (modified), UV-Nikkor 105 mm f/4.5 reversed plus extension, internal Baader U2" (Venus) filter, Broncolor studio flash with uncoated Xenon tube, magnification m=1.7. Link to comment
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now