Flora & Fauna

Unable to exist without their host

Such is the life of Cistanches and Broomrapes

If you visit in the spring and explore either the Ria Formosa or the hills then you will almost certainly see this family as not only are they distinctive but they are the largest in number of all parasitic plant families.

Yellow Broomrape
This is a ‘holoparasite’ plant, totally reliant on its host

Orobanchaceae (Broomrape) attach themselves as seedlings to the roots of their host plants. Some are ‘holoparasite’ which means they lack chlorophyll and consequently totally rely on the host plant for all their nutrients. Others are ‘hemiparasite’ which means they have chlorophyll once mature and can photosynthesise. They do though also obtain water, with its dissolved nutrients, from their host. The way to tell which are which is by their stem colour – brown means ‘holoparasite’ and green is ‘hemiparasite’.

parentucellia-viscosa
Parentucellia viscosa is a ‘hemiparasite’. It is green!

Both the ‘holoparasite’ and the ‘hemiparasite’ can kill their hosts. It isn’t intentional, but the manner in which they attach themselves to the root weakens the roots of its hosts. In some areas around the world Orobanchaceae have become a major problem by attaching themselves to crops. An infestation can lead to the destruction of 20 to 100 percent of crops, and to make matters worse they are not easy to eradicate as their seeds can last for decades in the soil and each plant can produce between 10,000 to 1,000,000 seeds. Of course when I first saw them I wasn’t thinking about their killer instincts. I was just enjoying the colours, as some of the species do look incredibly pretty in spring!

My essential flower guide ‘Wildflowers of the Algarve’ is superb but one of the faults is that it doesn’t always tell you the English name and never advises as to the Portuguese names. This makes it doubly hard for me to remember the names of anything! So this next member of the orobanchaceae family is probably ‘Phelipanche nana’ but its English name could be ‘Nodding Broomrape’, ‘Branched Broomrape’, ‘Hemp Broomrape’ or even ‘Violet Dwarf Broomrape’. It all got very confusing when I looked on the internet.

Recent research has found that the Orobanchaceae family is monophyletic, ie they all share a common ancestor. No wonder some look very similar, and I am struggling with identification as well as names. I have yet to determine whether all of the following are ‘Cistanche phelypaea’ or whether some are ‘Orobanche foetida’. I’m not sure I am really interested enough to ever solve it as when out in the field I’m happy if I remember they are Broomrape!

7 comments on “Unable to exist without their host

  1. That last selection is positively sinister!

    Liked by 1 person

  2. So interesting! I have never heard of them before, so your post taught me something new!

    Liked by 1 person

  3. I remember being quite astounded seeing them growing in the water in the salt marshes. 🙂

    Liked by 1 person

    • I know they are extraordinary. Most of the ones in my final gallery were taken at low tide so at high tide not sure you’d even see some of them. I certainly couldn’t work out who their hosts were.

      Liked by 1 person

  4. They are beautiful flowers. The problem with names is, the Latin onesare long and hard to remember, but the commpn ones, even in the same country, vary from region to region. Keep on posting these lovely photographs.

    Like

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