Journal archives for March 2021

March 29, 2021

Resources for identifying dandelions to section

British Columbia paper cataloguing overlooked dandelion diversity:
https://cdnsciencepub.com/doi/10.1139/cjb-2018-0094

Key here: https://forum.inaturalist.org/t/overlooked-dandelion-diversity-in-bc-and-everywhere-in-north-america/3808/54 / https://cdnsciencepub.com/doi/pdf/10.1139/cjb-2018-0094#page=4

Terms:
Appressed: Laying flat against
Corniculate: Having a knob or horn (at the end of a bract)
Cyprela: Seed
Involucre: Bracts around the base of the flower
Glaucous: Pale greyish, maybe waxy or powdery coating
Hamate: Hooked at the tip
Crisped: Edge of leaf curled or ruffled
Rugose: Rough or wrinkled surface, e.g. creases from veins underneath the leaf
Oblanceolate: With a wide end of the leaf and tapering towards a thin base of the leaf (opposite of lanceolate)
Obovate: Egg-shaped, with the wide end at the end of the leaf
Capitula: Flower head
Ligule: The petal part of a ray flower's florets
Abaxial: On the underside or outside

More images of specimens examined for the paper here: https://morphobank.org/index.php/Projects/Media/project_id/3346

Going through the sections in the paper

More terms
arachnoid: Covered with thin soft hairs or fibres
strigillose: Covered with stiff thin bristles
sagittate: Shaped like an arrowhead
ampliate: Having a prominent outer edge
heterophyllous: Having multiple kinds of leaves
dentate: With toothlike projections


British dandelions (note that section Ruderalia is now considered section Taraxacum while what they refer to as Taraxacum is now Crocea I think)

Rest of Europe

Other
https://ueaecologyakane.wordpress.com/2020/04/14/identificaiton-of-a-dandelion-taraxacum/
Victoria, Australia https://vicflora.rbg.vic.gov.au/flora/taxon/6cfc234d-fbd2-4e23-8a3b-24b71daaeeff
1985 designation of new type specimen in section Crocea https://www.jstor.org/stable/1222201 then 2011 designation of new type in section Ruderalia https://www.jstor.org/stable/41059837 (causing changes of definitions where those sections are respectively renamed section Taraxacum)
FNA: http://floranorthamerica.org/Taraxacum
Section Palustria in Ontario... https://www.researchgate.net/publication/274251093


Basically you need good photos of the leaves from early in the year (April/May?), side/underside of the flower, and whether or not there is pollen on the stigmas. It seems helpful to measure the dimensions of the outer bracts (length and width).

Curious to see if anyone tries this stuff out. I don't have any good observation to try out yet since they're all from regularly mown grass or from in the summer...

Posted on March 29, 2021 11:29 AM by upupa-epops upupa-epops | 9 comments | Leave a comment