Wednesday, November 7, 2012

Bitterweed - Helenium amarum



Bitterweed (Helenium amarum) gets little respect with regard to its common name - or the common name of the genus - sneezeweed, but despite this, it is an attractive little wildflower that occurs throughout much of Florida in open fields, disturbed sites and open woodlands.  It also is widely distributed outside of Florida, occurring in nearly every state east of the short grass prairie states and also in California.  Throughout its range, it is generally regarded as a weed, because it rapidly colonizes disturbed ground.
Bitterweed is an annual that reseeds heavily in open soil.  Growth is rapid in the spring, and by late summer it stands between 2-3 feet tall.  The foliage is finely dissected - hence one of its other common names, yellow dogfennel.  The main stem does not branch much unless it is injured early in its growth stage, so it is upright and not very wide in aspect.
Flowering occurs at the top of each main stem in late summer to very early fall.  The bright yellow ray petals surround a rounded central disc and are attractive.  These look a bit like a yellow blanketflower (Gaillardia spp._ and it has been placed in this genus in the past.
Because of its tendency to spread, bitterweed is not a good candidate for most landscape settings. In open expansive dry sites, however, it could make an attractive addition.  It would be controlled by lack of open space in a well-planted landscape and the addition of taller perennials.  It is not currently propagated by any nursery affiliated with FANN - the Florida Association of Native Nurseries and it is unlikely to be any time in the future.  Seed collected from dry spent flower heads germinates easily if you want to try it yourself.

2 comments:

  1. I had a bit of Helenium amarum in the garden, that I encouraged...
    after I saw what it was capable of... due to those stolons, I declared war. I wiped it out by hand-pulling it!
    Very surprising that a plant with that amount of stoloniferous activity could be eradicated that easily.
    Was actually thinking about re-introducing it... when I discovered seedlings in another part of the garden a couple of years later.... will be keeping a close watch.

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  2. Helenium amarum is now available as seed from the Florida Wildflowers Cooperative (www.floridawildflowers.com). I bought a small packet, which I haven't yet sown. Now I'm wondering if I should!

    I've spent years trying to keep Spanish Needles (Bidens alba) under control, after sowing some wild-collected seed (from a disturbed area near a road). I don't want to get rid of it since pollinators like it, but it is a challenge. (Do you know that it can get 4-5' high, with a stem 1.5" wide?)

    I'll probably sow the Bitterweed, but at least now I know what I'm getting into and I'll pick its spot carefully.

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