Tag Archives: Flowers

Ghost flowers in the nettle family

Boehmeria-zollingeriana-AM7498 15-05-07_103123_M=A_R=8_S=4 v4
A pickled Flower of Boehmeria zollingeriana, 1.2 mm in length viewed under a Zeiss Axioskop microscope. You can clearly see the two stigmas (ling filament like structures) and if you look carefully the two overlapping eggs within the ovary (dark egg-shaped structures)

Nettles are characterised, amongst other things, by having flowers with a single egg in their ovary and a single stigma, the structure which conducts the pollen to its target. Work by developmental biologists almost a century ago suggested that the ancestor of nettles probably had two eggs per ovary after discovering that at a very early stage of development nettle ovaries contain two eggs one of which disappears as the flower develops resulting in the single egged flower which characterises the family. It was therefore a great surprise when plant collections from Costa Rica examined in the 1990s were found to have flowers with two or three eggs and stigmas per ovary. These very unusual plants were described as a new species: Boehmeria burgeriana  by colleagues Melanie Wilmot-Dear and Ib Friis. Continue reading Ghost flowers in the nettle family

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