Visions from nature

Alpine bistort and vivipary

By Anders L Kolstad

Alpine bistort (Bistorta vivipara) is a well know plant for many. It if found throughout Norway and in many diverse habitats, from road verges to meadows. It’s characteristic and doesn’t closely reassemble any other plant. In the summer the bistort produces lots of flowers along a narrow spike. I don’t know how much the plant gains from this extravagant show – it rarely develops seeds. On the other hand it spreads willingly though dispersal of so called bulbils, small clones of the plant that superficially resemble seeds. These bulbils are nurtured by the mother plant far into the autumn as if it doesn’t want to see its clone babies go. Sometime it goes so far as that the bulbils start growing while still attached to the mother plant. The reason for all this is that the alpine bistort is trying to prepare the (clonal) offspring for the world by letting them complete the first and most dangerous part of their life whilst still enjoying the benefits of the mother’s root system. The flip side of this strategy is that the bistort becomes highly attractive to plant eating animals like grouse and geese, who enjoy the energy condense bulbils and also root nodules.

Harerug blomstrer rikt om sommeren, men setter sjelden frukt.
Alpine bistort produce lots of flowers, but rarely set seeds. Photo: Anders L. Kolstad NTNU University museum. CC BY-SA 4.0.
Mot høsten dannes det yngleknopper. Disse ser ut som frø, men er i realiteten kloner av morplanten.
Towards the autumn bulbils are formed. These may look like seeds, but are in fact identical clones of the mother plant. Photo: Anders L. Kolstad NTNU University museum. CC BY-SA 4.0.

Other examples of vivipary in the Norwegian flora are found in the family of grasses, such as Poa vivipara, Festuca vivipara, and Deschampsia alpina. You can see a pattern in that this strategy of parental care is more common in stressful or marginal environments, such as alpine/arctic habitats, and brackish meadows and mangroves. This is likely due to the fact that seedling survival and germination percentages are so low here that the mother plants must help their young ones with a head start to their though life.


What is vivipary?

Vivipary actually means to give birth to life young ones, like what humans do. Birds lay eggs (equivalent to plant seeds), but these don’t qualify as ‘alive’ by this definition. In the case of alpine bistort, the specific epithet vivipara refers to the bulbils who may germinate or start to grow whilst still attached to the mother plant, so that when they are released, they are already ‘alive’. About half the cases of vivipary in plants is of this type, and the other half is ‘true vivipary’ with real seeds that germinate inside the flower (common for mangroves).


Read more about vivipary here.

This post is part of a series of shorter plant stories.

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