Arctic avens (Dryas integrifolia)

Description

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Arctic avens fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
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Arctic avens description

The Arctic avens (Dryas integrifolia) is an evergreen dwarf shrub with multiple large, solitary flowers ^{(2) (3) (5)}. The flowers are composed of 8 to 11 creamy-white oval petals, with between 40 and 70 stamens in the centre. The stamens have hairless stalks and yellow anthers ^{(3) (4) (6)}. The flowers are supported by an erect stem which has flaky bark ⁽⁷⁾. The stems of the Arctic avens intertwine to form the flat, dense mats created by populations of this species ^{(3) (6)}.

The leaves of the Arctic avens are leathery, with a dark green, hairless upperside and a white underside, which has dense, matted hairs on the surface ^{(4) (7) (8)}. The smooth outline of the leaves is reflected in the scientific name integrifolia, which means ‘entire leaves’ ⁽⁹⁾. The lance-shaped leaves have prominent, indented veins on the surface, as well as rolled edges and a pointed tip ^{(3) (7) (8) (9)}. The leaves of the Arctic avens are arranged in a dense rosette at the base of the stem ⁽²⁾.

The petals inside the scaled buds of the Arctic avens can occasionally appear black due to the dense hairs within. However, these may not always be present and the petals within the bud sometimes appear grey-green ^{(6) (7)}.

The single-seeded fruit of the Arctic avens is brown and has long hairs on its surface ^{(3) (6)}.

Size

Height: 8 - 10 cm ⁽²⁾

Leaf length: c. 1 cm ⁽³⁾

Flower diameter: up to 3 cm ⁽²⁾

Arctic avens biology

The Arctic avens is a long-lived, perennial plant ⁽¹¹⁾, which usually flowers between June and July ⁽⁷⁾, with the buds beginning to develop the autumn before the flowering season ⁽³⁾. The bud opens in one day, followed by the opening of the anthers ⁽³⁾.

The flowers of all of all Dryas species are ‘heliotrophic’ meaning they show directional growth towards the sun ⁽⁶⁾. As an adaptation to help the Arctic avens develop faster in the cold Arctic the corolla of the flower tracks the movements of the sun ⁽⁵⁾, reflecting the heat energy onto the reproductive organs in the centre of the flower ⁽¹²⁾. The flowers are attractive to many insect species ⁽⁵⁾.

There are also many other adaptations of the Arctic avens which enable it to exist in the Arctic. The formation of rosette and cushion structures by Arctic plants enables them to function while remaining low and close to the ground, where there is more favourable growing conditions ⁽²⁾. The root system of the Arctic avens is very limited, develops slowly and is functional for many years, relying recycling as a source of nutrients rather than uptake from the nutrient-poor Arctic soil ⁽⁵⁾. The long hairs of the achenes enable the Arctic avens to spread its seeds by wind dispersal ⁽³⁾.

Arctic avens range

The Arctic avens has a wide distribution, ranging from Alaska in the east to Greenland in the west, including Canada and many North American Arctic Islands ^{(4) (6) (10)}. In Canada, the Arctic avens is found in Newfoundland, Quebec, Labrador, Gaspé, Hudson Bay, Alberta and the northern shore of Lake Superior ^{(7) (11)}.

Arctic avens habitat

The Arctic avens inhabits Arctic tundra ^{(4) (6)}, where it is usually found growing on slopes in neutral to alkaline soils among rocks and gravel ^{(2) (9) (11)}.

Arctic avens status

The Arctic avens has yet to be classified by the IUCN.

Arctic avens threats

There are not currently known to be any major threats to the Arctic avens.

Arctic avens conservation

There are not known to be any specific conservation measures currently in place for the Arctic avens.

Find out more

Find out more about plant conservation:

• Plantlife International:
  http://www.plantlife.org.uk/international

Find out more about the habitat of the Arctic avens and its conservation:

• ARKive - Arctic:
  http://www.arkive.org/eco-regions/arctic/

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Achene

A simple single-seeded fruit that falls from the plant in one piece. Achenes usually in occur in clusters.

Alkaline

Having a pH greater than 7.0. Soil is regarded as alkaline if it has a pH between 8.0 and 10.0. Alkaline soils are usually rich in calcium ions.

Anther

Part of the stamen (the male reproductive organ of a flower) that produces pollen.

Corolla

A collective term for all the petals of a flower.

Evergreen

A plant which retains leaves all year round. This is in contrast to deciduous plants, which completely lose their leaves for part of the year.

Genus

A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

Perennial

A plant that normally lives for more than two years. After an initial period, the plant usually produces flowers once a year.

Stamen

The male reproductive organ of a flower. Each stamen is comprised of an anther (the pollen-producing organ) and a filament (stalk).

Tundra

Treeless, grassy plains characteristic of Arctic and sub-Arctic regions. They are very cold and have little rainfall.

References

1. Integrated Taxonomic Information System (ITIS) (February, 2012)
   http://www.itis.gov/
2. Chernov, Y.I. (1985) The Living Tundra. Cambridge University Press, Cambridge.
3. Philipp, M., Böcher, J., Mattsson, O. and Woodell, S.R.J. (1990) A quantitative approach to the sexual reproductive biology and population structure in some arctic flowering plants: Dryas integrifolia, Silene acaulis and Ranunculus nivalis. Bioscience, 34: 1-61.
4. Brayshaw, T.C. (1996) Trees and Shrubs of British Colombia. Royal British Columbia Museum, Canada.
5. Bliss, L.C., Heal, O.W. and Moore, J.J. (Eds.) (1981) Tundra Ecosystems: A Comparative Analysis. Cambridge University Press, Cambridge.
6. Aiken, S.G. et al. (1999 onwards) Dryas integrifolia. In: Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version 29th April 2003. Canadian Museum of Nature, Ottowa. Available at:
   http://www.mun.ca/biology/delta/arcticf/_ca/www/rodrin.htm
7. Petrides, G.A. (1972) Trees and Shrubs. Houghton Mifflin Company, New York.
8. Cody, W.J. (2000) Flora of the Yukon Territory. Second Edition. National Research Council of Canada, Ottawa, Canada.
9. Hallworth, B. and Chinnappa, C.C. (1997) Plants of Kananaskis Country in the Rocky Mountains of Alberta. University of Alberta Press, Alberta.
10. Levere, T.H. (1993) Science and the Canadian Arctic. A Century of Exploration 1818-1918. Cambridge University Press, Cambridge.
11. Tremblay, N.O. and Schoen, D.J. (2002) Molecular phylogeography of Dryas integrifolia: glacial refugia and postglacial recolonization. Molecular Ecology, 8: 1187-1198.
12. Huggett, R.J. (1998) Fundamentals of Biogeography. Second Edition. Routledge, Oxfordshire.