Potentilla crantzii [Alpine Cinquefoil]

[nfoto]

Rørslett, B. 2013. Potentilla crantzii (Crantz) Beck ex Fritsch (Rosaceae). Alpine cinquefoil. Flowers photographed in visible and ultraviolet light. http://www.ultraviol...ine-cinquefoil/

 

Potentilla crantzii (Crantz) Beck ex Fritsch.

Syn. Potentilla verna auct. non L.

NO: Flekkmure

SE: Vårfingerört; fläckfingerört

DK: Guld-Potentil

FI: Keväthanhikki

IS: Gullmura

DE: Zottiges Fingerkraut

EN: Alpine Cinquefoil

 

A small prostrate plant native to Eurasia and also occurring in Northern America, P. crantzii is regarded as an alpine species in continental Europe. However, in the Nordic countries it is frequently found in lowland regions often on calcareous soils, plus occurring on alpine sites with sparse vegetation cover, again on richer soils. Taxonomy in this genus is difficult and the taxon has been confused with other close relatives over the years. P. crantzii flowers early in the lowlands, often late April or early May, while in the mountains it commences flowering in June.

 

Plants collected near Oslo, Norway 5 May 2009. This population had less prominent red spots on the petals than usually encountered for P. crantzii, but keyed to that species in all other aspects. This species is regarded as a regular component of the plant communities on the alvar-like biotopes typical for the islands of the inner Oslo Fjord.

 

Image reference: POTE_CRA_I0905058430_VIS.jpg

Visible light: Nikon D200, Coastal Optics 60 mm f/4 lens, Baader UV/IR Cut filter, daylight

 

Image reference: POTE_CRA_I0905058431_UV.jpg

Ultraviolet light: Nikon D200, Coastal Optics 60 mm f/4 lens, Baader U2" (Venus) filter, Broncolor Minicom studio flash (uncoated Xenon tube)

 

Many Potentilla species have dark UV guides on the basal part of their petals, but P. crantzii is obviously not one of these. However, there are indications of darker basal areas. Interestingly these are much larger than the visible red spots at the petal base.The petals have conical cells profusely developed near the tip. Tracers of iridescence are also seen. The pollen tends to fluoresce and appears rather bright on this photograph. Bracts are almost shiny UV-white as well.

 

[Published 29 Apr 2013]