Thursday, September 18, 2014

Plant of the day is: Spartium junceum or Spanish broom

Plant of the day is: Spartium junceum or Spanish broom

Well it has a yellow flower and it is from Spain, so I like those things.  Invasive on the west coast, so I don't like that.  Not the plants fault though, I sometimes have to remind myself to not be annoyed AT a plant, and remind myself that it was just a dumb humans fault I have to contend with it.

Taxonomy, etc:  A member of the Fabaceae family, Spartium junceum is the sole member of the monotypic genus Spartium.  There are a whole slew of synonyms and unresolved listings for other species of Spartium, but the taxonomists apparently just aren't having it.  Sadly within the last few mintues I haven't found much else of taxonomic interest so I'll make a reference to the flower structure of legumes, because they are usually VERY identifiable by their flowers.  Here is a diagram showing one of their distinctive flowers.  NOT a Spartium ...just an illustrative picture.  The notable feature is the banner and keel of the flower.

Wisteria sinensis flower, to give credit to the plant.
Habitat:  Originally a native of the Mediterranean region and southewest Asia and and northwest Africa.  Now it exists in several places throughout the world, it is found here in the United States along the western seaboard and is listed as invasive and/or a noxious weed in most of those states.  Also listed in Hawaii as well, I don't think they want it.  Here is a fun map of California invasive info.  http://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Spartium+junceum

Description:  Alright, now to the fun part about the plant, because it is an interesting and beautiful plant.  It is one of 4 nonnative invasive species that occur in North America.  It is a perennial shrub that grows between 3-5m, usually more along the 3 side I should think.  Stems are long, slender, and erect with very little branching, making for a nice habit.  The stems are cylindrical which harkens back to its species designation as junceum means 'rush like' ...like rushes Juncus.  It's got Juncus in the trunkus.  Stems are green when young and eventually develop a more woody look.  Leaves are very small and ephemeral and tend to only remain on the plant for about 4 months or so.  Why you ask?  Well, it's a pretty drought tolerant plant and leaves are a big source of transpirational loss.  The solution, just go ahead and photosynthesize right out of that stem, they do that.  Flowers are yellow about 1-2cm across and fairly good sized seed pods of 8-10cm can open with an audible crack when mature.  Pods have around 10 to 15 seeds in them.  Neat.  I wanna hear one.  This of course helps eject the seed which remains present in the soil or soil bank, as it is called, for several years, making control of established areas difficult.  The roots, apparently change quite a bit dependent on the slope and type of soil, which is laudable.  

Culture:  Monrovia lists this as zone 7-10 while other sites list it as zone 8 hardy.  In all likelihood Saint Louis is still too cold for this plant to hang around as a perennial.  Any given year could produce a winter cold enough to really knock it back.  How well seeds handle exposed cold, I don't know.  They like it hot, dry, and sunny.  Situate appropriately.  Does not appreciate root disturbance and requires a bit larger container if you are wanting to start from seed.  Don't start in a seed tray, I'll say that.  

Great info from the forest service on this, as they've done some assessments for fire potential.  Dense colonies of this can form, and provide very good tinder for forest fires during periods of drought.


Fun (or not so fun) facts:
  • Originally planted in California in the ornamental trade in 1848 in San Francisco.  
  • In the 1930s it was planted along mountain highways in southern Californa.  Great idea!
  • Humans are, historically speaking, dumb when it comes to moving plants.
  • LESS of an invasive species than the other brooms, Scotch (Cytisus scoparius) and French (Genista monspessulana).
  • Branches can be made into brooms (ahhhh broom...there it is).
  • Yellow die can be made from the flower.
  • An oil from the flowers is used in perfumes.

That's it for now really I suppose, if you do try it, situate it in a protected but sunny position (tall order I know) and do keep an eye out for seedlings and by all means, let me know if you see any, I'm curious.
Great image of the habit.

Up close on the flowers, very leguminous

Even better shot of the flowers, a good one.
CC BY-SA 2.5 Photo Credit: שריף עסאקלה

I believe the above picture was taken from the Maghar village in Israel.  Neat.


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