Strophanthus divaricatus
This plant has a very distinctive flower.   When the flower is a bud, its 5 tepals unite and their tips become strings which are intertwined to form one string.   At the beginning, the bud is light green, and gradually turns to deep yellow.   The flower blooms during this process.   The tepal has a reddish purple pattern and each string unravels and hangs down.   Capturing this characteristic, the genus name "Strophantus" comes from the Greek words, "strophos" meaning a twisted string and "anthos" meaning a flower.   In the Sun Gallery, there is another similar flower which is called Strophanthus preussii.
The fruit of this plant is also distinctive.   The fruit divides to form two fruits which look like two spindles combined horizontally.   Capturing this characteristic, the epithet, "divaricatum" comes from the word "divaricate" which is a term used to describe the pattern of roughly horizontal branching.   When the fruit ripens, it becomes wooden.   Many thin and long seeds are packed into the fruit.   The tip of this seed is elongated and has long silky hairs.
This plant contains a cardiac glycoside, strophantin in the whole plant and there is especially high content in the seed.   Somali people in Africa used this seed as a raw material for the poisoned arrow.
Strophantin is a mixture of glycosides of strophantidin.   Strophantin is strong drug for increasing Cardiac Contractile Force, and G-strophantin has medical use.   This compound is highly water soluble, very rapid acting and quite transient and so is used for medical experiments (a specific blocking agent for Na+,K+-ATPase) and pharmaceutical experiments.   However it does not often have a clinical use as it is poorly absorbed from the gastrointestinal tract.   It is used as a cardiac stimulant in Germany and France.
Note:
This compound has a depressant action for Na+,K+-ATPase but it is not clear whether the depressant action is the mechanism of the action of increasing Cardiac Contractile Force.
Classification Apocynaceae Strophanthus
Scientific name Strophanthus divaricatus (Lour.) Hook. et Arn.
Japanese name Kinryuka
English name ---
Native locality Southern Part of China, Vietnam, Laos
Ecological description Evergreen climbing shrub
RDB ---
Planting place Sun Gallery
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