Pin (a, c, e, g) and thrum (b, d, f, h) pollen grains of Primula
![Pin (a, c, e, g) and thrum (b, d, f, h) pollen grains of Primula](https://www.researchgate.net/publication/274826218/figure/fig2/AS:294729725038593@1447280450159/Pin-a-c-e-g-and-thrum-b-d-f-h-pollen-grains-of-Primula-vulgaris-comparatively.png)
![](https://www.researchgate.net/publication/256074629/figure/fig1/AS:340657668411415@1458230525549/P-allionii-measurements-detected-in-thrum-a-and-pin-b-flowers-according-to-Fey.png)
P. allionii measurements detected in thrum (a) and pin (b) flowers
![](https://www.treesandshrubsonline.org/site/assets/files/3471/forsythia.jpg)
Forsythia - Trees and Shrubs Online
![](https://media.springernature.com/lw685/springer-static/image/chp%3A10.1007%2F978-3-642-15518-5_9/MediaObjects/978-3-642-15518-5_9_Fig19_HTML.gif)
Evolution SpringerLink
![](https://www.researchgate.net/publication/10768651/figure/fig3/AS:374900800933891@1466394724612/a-f-Scanning-electron-micrograph-SEM-images-of-acetolysed-pollen-grains-of.png)
a–f. Scanning electron micrograph (SEM) images of acetolysed pollen
![](https://besjournals.onlinelibrary.wiley.com/cms/asset/258059ef-0495-452f-99be-3ef5bbdf5367/jec_1513_f3.gif)
Biological Flora of the British Isles: Primula vulgaris Huds. (P. acaulis (L.) Hill) - Jacquemyn - 2009 - Journal of Ecology - Wiley Online Library
![](https://www.researchgate.net/publication/225167156/figure/fig3/AS:669218777354250@1536565598442/Pollen-grains-on-and-pollen-tube-growth-within-a-LSstigma-and-pistil-in-Pulmonaria.png)
Pollen grains on, and pollen tube growth within a LSstigma and pistil
![](https://www.mdpi.com/ijms/ijms-19-01840/article_deploy/html/images/ijms-19-01840-g004-550.jpg)
IJMS, Free Full-Text
![](https://c8.alamy.com/comp/RR7MG8/the-abc-and-xyz-of-bee-culture-a-cyclopedia-of-everything-pertaining-to-the-care-of-the-honey-bee-bees-hives-honey-implements-honey-plants-etc-bees-fig-3cross-sections-ok-dimorphic-flower-primula-vulgaris-common-primrosi-order-pnmulaceai-a-long-styled-floweri-stigma-st-style-a-anther-o-ovary-pg-pollen-grains-more-magnified-b-short-styled-forma-anther-i-stigma-st-style-o-ovary-per-pollen-grains-more-magnifiedfrom-chcshirr-back-is-ruffled-up-the-wrong-way-ow-this-would-be-pretty-cer-tain-to-get-the-pollen-dusted-all-over-it-but-natu-RR7MG8.jpg)
Long stigma flower hi-res stock photography and images - Page 6 - Alamy
![](https://www.mdpi.com/ijms/ijms-19-01840/article_deploy/html/images/ijms-19-01840-g002b.png)
IJMS, Free Full-Text
![](https://www.mdpi.com/plants/plants-11-01047/article_deploy/html/images/plants-11-01047-g007.png)
Plants, Free Full-Text
![](https://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Hypericum_aegypticum_2.jpg/1200px-Hypericum_aegypticum_2.jpg)
Hypericum aegypticum - Wikipedia
![](https://www.researchgate.net/publication/10814028/figure/fig4/AS:669096601481236@1536536469578/Distribution-of-pollen-grains-in-the-bill-of-a-Copper-rumped-Hummingbird-adhered-to-it.png)
Distribution of pollen grains in the bill of a Copper-rumped
![](https://pennyphilcox.files.wordpress.com/2016/04/img_8200.jpg)
Pin-eyed and Thrum-eyed Primrose Sheffield city nature diary by Penny Philcox
![](https://nature.berkeley.edu/blackmanlab/Blackman_Lab/Lab_News/Entries/2017/1/23_Bloom_of_the_Week_-_files/shapeimage_1.png)
Bloom of the Week - The Heterostyly Supergene Identified