Osteospermum grandiflorum [Stinkbietou]

[nfoto]

Rørslett, B. 2015. Osteospermum grandiflorum DC. (Asteraceae). Stinkbietou. African flowers photographed in visible and ultraviolet light. http://www.ultravioletphotography.com/content/index.php/topic/1553-osteospermum-grandiflorum/

 

A small foetid shrub, found in fynbos on the Kamiesberg near Kamieskroon, North Cape province, South Africa. The large, yellow capitula occur in great profusion.

 

Image reference: OSTE_GRA_G1509066598_VIS

Visible light: Nikon Df, Voigtländer 125 mm f/2.5 APO-Lanthar lens, daylight.

 

Front view of the flower heads in UV,

 

Image reference: OSTE_GRA_I1509062790_UV

 

Rear view of the same, showing the involucre. Do note that the ray flowers when young have a different UV appearance on their lower side than as fully developed.

 

Image reference: OSTE_GRA_I1509062791_UV

 

Ultraviolet images captures with Nikon D3200, UV-Nikkor 105 mm f/4.5 lens, Baader U2" (Venus) filter (built-in), SB-140 flash.

 

References:

http://www.ultraviol...-r%C3%B8rslett/

 

[ Published 18 November 2015]

[Andrea B.]

We have seen that abaxial veining before in various Asteraceae. Very nicely delineated in this one.

Are those actual veins or simply some kind of pigmentation? Are they present on the visible abaxial surface?

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Don't think I have this requested view for O. grandiflorum, but other Osteospermum species show a similar vein pattern on the underside of the ligules. In visible light they are seen as raised nerves, but without any difference in appearance.

 

Do note that these nerves may arise from the fusing of individual corolla segments on the ray florets. Most composite species have 3, some 4 or 5, such elongated segments shown by the corresponding number of teeth on the tip of the ligule.