Andrea B. Posted March 3, 2021 Share Posted March 3, 2021 Blum, A.G. (2021) Xanthisma spinulosum (Pursh) D.R. Morgan & R.L. Hartman (Asteraceae) [spiny Goldenweed] Flowers photographed in ultraviolet and visible light. https://www.ultravio...eed/#entry43270 SET 1Found along Rodeo Drive, Santa Fe, New Mexico, USA24 Oct 2019Wildflower Other Common Names:Cutleaf GoldenweedLacy Sleepy DaisyLacy TansyasterWooly GoldenweedYellow Spiny DaisySynonyms:Amellus spinulosus PurshDiplopappus pinnatifidus HookerHaplopappus spinulosus (Pursh) de CandolleMachaeranthera pinnatifida (Hooker) ShinnersThis is the most recent previous name for X. spinulosum.Many more synonyms are listed in the SEINet entry[4]..Comment:The white bristle at the end of each leaf and phyllary gives the plant its genus name. Those bristles also help to identify the plant given that there tends to be some morphological variations in plant size, number of rays, ray length, hairiness and other features amongst the Xanthisma subspecies. I have enjoyed seeing the X. spinulosum clear yellow stars on the roadsides in my area where the plant is very common. Like many UV-absorbing Asteraceae, this flower shows some iridescent striping along its rays. References: 1. Allred, Kelly W., Jercinovic, Eugene M., Ivey, Robert DeWitt (2021) Flora Neomexicana III: An Illustrated Identification Manual, Second Edition, Part 2, Taxon Key, page nnn. Print on demand at lulu.com.2. Finley, Willa F., Nieland, Lashara J. (2013) Land of Enchantment Wildflowers. Xanthisma spinulosum, page 83. Texas Tech University Press, Lubbock, Texas.3. SEINet Arizona-New Mexico Chapter (acc nn mmm 2021) Xanthisma spinulosum.This is a southwestern biodiversity organization making use of the Symbiota portal software.4. Southwest Colorado Wildflowers (acc nn mmm 2021) Xanthisma spinulosum.Website published and maintained by Al Schneider and hosted by Rocky Mountain Biological Laboratory.5. Wildflowers of New Mexico (acc nn mmm 2021) Xanthisma spinulosum.Website published and maintained by George Oxford Miller. Equipment [Nikon D610-broadband + Nikon 105mm f/4.5 UV-Nikkor] Visible Light [f/11 for 1/20" @ ISO-800 under Ambient Skylight with Baader UVIR-Block Filter]I don't know why those petals are wrinkled. Maybe they did not completely unfold when blooming. Visible Light [f/11 for 1/8" @ ISO-800 in Sunlight with Baader UVIR-Block Filter]Note the bristles at the tips of the pinnatifid leaves. Ultraviolet Light [f/11 for 4" @ ISO-800 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]The iridescent striping does not vary much by location on the rays (edges and along grooves),but it does turn off/on depending on the angle of the UV illumination. Visible Light [f/11 for 1/20" @ ISO-800 with Onboard Flash and Baader UVIR-Block Filter]The pappi are about 4-6mm long and quite evident here. Ultraviolet Light [f/11 for 4" @ ISO-800 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]The ray iridescence is more pronounced abaxially and not confined to striping. Ultraviolet Light [f/16 for 1.3" @ ISO-800 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]These two flowers are from the same plant as the preceding example. SET 2El Dorado at Santa Fe, Santa Fe, New Mexico, USANear Avenida El Dorado & Avenida Torreon 10 June 2020 Visible Light [f/8 for 1/500" @ ISO-125 with D850 + Micro-Nikkor 60/2.8G ED AFS]A typical X. spinulosum along the roadside. Equipment [Nikon D610-broadband + Nikon 105mm f/4.5 UV-Nikkor] Visible Light [f/16 for 1/2.5" @ ISO-200 with Onboard Flash and Baader UVIR-Block Filter] Ultraviolet Light [f/16 for 20" @ ISO-200 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]Two flashes were made in the 20" interval for better illumination. Link to comment
Andy Perrin Posted March 3, 2021 Share Posted March 3, 2021 I like the colors on the UV here. Link to comment
Andrea B. Posted March 3, 2021 Author Share Posted March 3, 2021 Me too. The false blue pollen is always nice in a dark flower. That first flower seemed newer than the last two, so I think that's why the blue is stronger in the first flower? Of course, there's always some variation in the conversions due to amount and angle of lighting. Link to comment
Cadmium Posted March 18, 2021 Share Posted March 18, 2021 Andrea, I like that visual group photo (#7), would like to see that one in UV+Blue+Green. Link to comment
Andrea B. Posted March 18, 2021 Author Share Posted March 18, 2021 Thx. I will try to make some UV+B+G photos this spring and summer. Link to comment
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