4 replies to this topic

[nfoto]

Rørslett, B. 2014. Cymbalaria muralis P. Gaertn., B. Mey. & Scherb. (Schrophulariace; Plantaginaceae). Ivy-leaved Toadflax. UV signature with conical cells. Flowers photographed in visible and ultraviolet light.
http://www.ultraviol...-conical-cells/

Cymbalaria muralis P. Gaertn., B. Mey. & Scherb.
Syn. Antirhinnum muralis L.; Linaria muralis (L.)Mill.
NO: Murtorskemunn
SE: Murreva
DK: Vedbend-Torskemund
FI: Kilkkaruoho
DE: Zymbelkraut
EN: Ivy-leaved Toadflax: Kenilworth Ivy

This small creeping species is a native of southern Europe and widely used as an ornamental plant. It easily escapes from cultivation and may become naturalised even in colder climates such as in the Nordic countries.

Material was collected and photographed near Oslo, Norway 13 Aug 2010.


Image reference: CYMB_MUR_I1008131038_VIS.jpg
Visible light: Nikon D40X (modified), UV-Nikkor 105 mm f/4.5 lens, Baader UV/IR Cut filter, daylight, m=1.5.


Image reference: CYMB_MUR_I10081312423_UV.jpg
Ultraviolet light: Nikon D40X (modified), UV-Nikkor 105 mm f/4.5 lens, Baader U2" (Venus) filter, Broncolor studio flash with uncoated Xenon tube.

From the original file (CYMB_MUR_I10081312423_UV.tif), I made two 100% crops to show better the amazing level of detail of the epidermal structures contained therein.





The first published UV signature of C. muralis was by Blum (2013): http://www.ultraviol...aved-toadflax/. My results are in principle identical, but the higher magnification discloses more details.

All photographs captured with the exact same camera and lens, by the way (D40X/UV-Nikkor). Just to illustrate how much more detail UV brings with it.

[ Published 15 July 2014 ]

[DaveO]

Is the bright blue false-UV color indicative of conical cells? I am seeing it quite often on Australian native wildflowers and I think I always see the conical cell texture at the same time.

Dave

[nfoto]

The conical cells are actually specialised epidermal hairs (trichome cells). As hairs go, they are very short however, and their shapes may alter considerably even within a given flower.

With the resolution we currently have at hand, we mainly detect conical cells when they are fairly long. See the brighter stripes on the 100% detail of the lower corolla lip. We also see epidermal cell structures which are less easy to categorise, but fairly often the rugose or ridged shapes indicate these cells may contribute towards iridescence as well. We see such cells forms scattered all over the corolla of C. muralis. The long conical cells seen on the lower lip are virtually absent from the upper lips of the corolla, though.

When the conical cells are not resolved due to insufficient magnification (or resolving power), their presence may still be manifested as velvety or shining areas of the flower. The flower appearance in UV will then vary with incidence angle of the UV light source.

[Andrea B.]

Those are gorgeous conical cell photos. Wow !!


Conical cells don't always have trichomes??

Whitney HM, Bennett KM, Dorling M, Sandbach L, Prince D, Chittka L, and Glover BJ (2011) Why do so many petals have conical epidermal cells? Annals of Botany 108: 609-616
Full text: http://chittkalab.sb...20Ann%20Bot.pdf


Although conical cells and trichomes do have a common developmental pathway.

B.J. Glover, M. Perez-Rodriguez and C. Martin (1998) Development of several epidermal cell types can be specified by the same MYB-related plant transcription factor. Development 125: 3497-3508.
http://dev.biologist...7/3497.abstract

[DaveO]

You may well have found these refs to conical cells yourself:

http://floweringhigh...right-visitors/

http://www.australia...ick-to-flowers/
http://www.abc.net.a...flowers/4129484

Dave