A portrait of the bearded Crassula (C. barbata)

It would be hard to come up with a more apt name for this interesting little gem which is not just beautiful, but also interesting in an ecological sense.
The following pictures show how dramatically the appearance of the plants changes between late autumn and late spring. Please bear in mind that the plants occur in the southern hemisphere, and also that they only grow in the cooler and wetter months (autumn to early spring). They  are almost always found in shade, under shrubs or rocks.

Crassula barbata
Mid May (late autumn)

crasbarb06-05-23_lzn1.1res.jpg
Late May

crasbarbDSC_3417_lzn-1res.jpg
Early August

crasbarb2009_09_27_067_lznres.jpg
Late September

crasbarb_DSC0245_lznres.jpg
Early October

crasbarb_DSC0533_lznres.jpg
End of  October (late spring)
Now that summer is approaching, the rosettes have closed to minimize transpiration.  As a result of this, the cover of long hairs at the same time acts as insulation against strong light and desiccating winds.

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2 Responses to A portrait of the bearded Crassula (C. barbata)

  1. Geoff Wyatt-Goodall says:

    Why do certain succulents change colour from green to red when exposed to bright sunlight?

    Like

    • fransnoltee says:

      Hi Geoff,

      Thanks for your question; it is always good to get a response from readers. I hope the following is of some use.

      The discolouration is caused by anthocyanins. It is believed to act as a kind of sunscreen by absorbing blue-green and ultraviolet light, so that photosynthetic tissues are protected from high-light stress.
      It is good to remember that the accumulation of anthocyanins can be induced by a host of other stress conditions as well: very high or low temperatures, wounding, infection, lack of nutrients or water.
      Apart from that it is also often seen in young seedlings, where the protective tissues in the epidermis have not been developed enough.
      The exact mechanisms involved in all this are not yet fully understood, as a quick tour of the internet will make clear.

      Like

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