title: Optical structure and function of the white filamentary hair covering the edelweiss bracts.
abstract: The optical properties of the inflorescence of the high-altitude Leontopodium nivale subsp. alpinum (edelweiss) is investigated, in relation with its submicrometer structure, as determined by scanning electron microscopy. The filaments forming the hair layer have been found to exhibit an internal structure which may be one of the few examples of a photonic structure found in a plant. Measurements of light transmission through a self-supported layer of hair pads taken from the bracts supports the idea that the wooly layer covering the plant absorbs near-ultraviolet radiation before it reaches the cellular tissue. Calculations based on a photonic-crystal model provide insight on the way radiation can be absorbed by the filamentary threads.
authors.affiliation: Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium. jean-pol.vigneron@fundp.ac.be
authors.forename: Jean Pol
authors.initials: JP
authors.lastname: Vigneron
authors.forename: Marie
authors.initials: M
authors.lastname: Rassart
authors.forename: Zofia
authors.initials: Z
authors.lastname: Vértesy
authors.forename: Krisztián
authors.initials: K
authors.lastname: Kertész
authors.forename: Michaël
authors.initials: M
authors.lastname: Sarrazin
authors.forename: László P
authors.initials: LP
authors.lastname: Biró
authors.forename: Damien
authors.initials: D
authors.lastname: Ertz
authors.forename: Virginie
authors.initials: V
authors.lastname: Lousse
mesh_terms: D019659:Asteraceae / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D003198:Computer Simulation; D006197:Hair / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D008027:Light; D008954:Models, Biological; D012031:Refractometry / Q000379:methods*; D013329:Structure-Activity Relationship