Montag, 23. September 2013

Plant of the Day (23rd September, 2013) - Datura stramonium L.

The next “Plant of the Day” is Datura stramonium L.; a species from the Solanaceae family. The common German name of this plant is “Gemeiner Stechapfel”. In English, the plant is known as “Jimson weed” or simply “Datura”.

1) Description

D. stramonium - habitus

D. stramonium is an annual plant, which reaches heights between 30 and 120 centimeters. The bald, strong stalk is hollow and fork-like branched (two branches per node). The leaves are egg-shaped and have a long petiole. Their margin is irregular lobated and the ground of the leaf blade is a little bit wedge-shaped. There are no stipules. 

D. stramonium - leaf
 
The flowers are in the axils of the branches with one flower per axil. They are trumpet-like shaped and have five sepals and five petals. The bright-green sepals are fused and form a five angular tube. The petals are white and funnel shaped. An interesting feature is the flowering, because the flowers are closed at day and open at night. The reason for this is, that the primary pollinators of D. stramonium are moths, which are nocturnal. Flowering time is between June and October.

D. stramonium - flowers

However, the most distinctive feature of D. stramonium are the fruits. After successful pollination, the flower transforms into a large (between 4 and 6 centimeters), egg-shaped fruit with a spiky surface. This spiky fruit is also the reason for the German name “Stechapfel” (literally: “piercing apple”). Each fruit is a capsule with five flaps and contains over 400 black seeds.

D. stramonium - capsule, you can also see the seam
of the flaps

All parts of the plant, but especially seeds and roots, are very toxic due to the high content of Hyoscyamin and Scopolamin. Both belong to a a special group of Alkaloids: the Tropanes. The tropanes are typical for the nightshades and have a strong hallucinogenic effect. However, even small doses can cause respiratory paralysis and death.

the Tropanes of D. stramonium


Despite this, the seeds of D. stramonium are used as drug. This is however not recommend, because this is very dangerous due the high toxicity.

2) Distribution

Originally, D. stramonium was native to Mexico but today it can be found all other world as a neophyte. It was imported to Middle-Europe during the 16th century. The species grows on disturbed areas like ruderal wastelands, dumps but also in garvel pits and even roadsides. It prefers nutrient-rich places to grow and is also tolerant toward salt.

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