Thursday 10 July 2014

AGERATUM

Ageratum houstonianum (flossflower, bluemink, blueweed, pussy foot, Mexican paintbrush) syn. Ageratum mexicanum Hort. is a cool-season annual plant often grown as bedding in gardens. The plant grows to 0.3–1 m high, with ovate to triangular leaves 2–7 cm long, and blue flowers (sometimes white, pink, or purple). The flower heads are borne in dense corymbs. The ray flowers are threadlike, leading to the common name.

The plant is native to Central America and adjacent parts of Mexico, but has become an invasive weed in other areas. Ageratum has evolved an ingenious method of protecting itself from insects; it produces a precocene compound which interferes with the normal function of the corpus allatum, the organ responsible for secreting juvenile hormone in insects. This chemical triggers the next moulting cycle to prematurely develop adult structures, and can render most insects sterile if ingested in large enough quantities.

Ageratum houstonianum is toxic to grazing animals, causing liver damage. It contains pyrrolizidine alkaloids. It is prone to becoming a rampant environmental weed when grown outside of its natural range. It has become an invasive weed in the eastern USA, Australia, Europe, Africa, China, Japan and New Zealand.

This post is part of the Floral Friday Fotos meme.


10 comments:

  1. Wow! I have never seen these before!

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  2. Wow! I have never seen these before!

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  3. Another neat color. Tom The Backroads Traveller

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  4. I can learn a great deal about flowers viewing your blog. Thanks for the education.

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  5. this is kind of a nostalgic plant to me, I remember it in gardens as a young child

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  6. Super!Never seen this flower before. Thanks!

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  7. Never seen before .... I think we have a similar plant here, but I'm Not sure.
    There are great captures for FFF !

    Heidrun from Germany

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  8. A very beautiful flower! Thank you also for the interesting facts!

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  9. I get this weed every year on a corner of my garden. And I let it grow, because the blue flowers are so pretty. Here in Virginia it blooms in the fall. I'm glad to know it's name now!

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