Hakea Invasions in Portugal and South Africa

General Scope of Project:

There has been much debate on iNaturalist about the identity of the Hakeas/Needlebushes invading Portugal and perhaps even South Africa. Historically we thought it was the Sillky Needlebush Hakea sericea, but there is increasing evidence that the Portuguese invader is Bushy Needlewood Hakea decurrens subsp. physocarpa.

This project hopes to involve Citizen Scientists to help sort out the issue. Briefly:

• What is the true identity of the Hakea sericea-like species in South Africa and Portugal?
• Is there only 1 invasive species in each country, or might there be some localized introductions of close relatives?

We require help from anyone interested. We need the following from as many populations as possible:
Please take observations from populations with the following photos (bold most important):

1. : flowerhead with open flowers - with mm rule (clearly showing flowerhead stalk, flower stalk, and pollen presenter, hairs on pollen presenter). Note the pollen presenter (pistil, style, gynoeceum) - the length from the base to the tip is the most important measurement of all. Close-up if possible to show hairs on the pistil.
2. : leaf on stem - with mm rule (clearly showing leaf stalk, and angle of leaves to stem, full leaf length, and leaf tip (mucro))
3. : close up of new/young branchlet to show the hairs
4. : follicle top view - with mm rule (showing the sculpturing on the surface, the size and shape of the horns)
5. : opened fruit if present showing the colors of the inside
6. : seeds if present (close-up)
7. : habit of plant (showing any resprouting tendencies)

The flowerhead photo has the most useful diagnostic characters (unfortunately, these involve size, which is why we need the rulers in the pictures), so please put this as the first picture on your observation. The order of the other pictures is not important.

Please feel free to record other information (for example, in South Africa you might include:

1. which biocontrols did you see? [Gummosis, Follicle Weevil, Follicle Moth, Girdling Weevil, other]. If you can photograph any of these - please do so as a separate observation, and include a link to the plant observation [use the "Interactions (s Afr)" project].
2. What proportion of plants are dying from Gummosis Fungus?
3. How old is the veld?
   
4. Habitat.)

Merely make observations: this project will collect the results and display them. You are welcome to do this for any Hakea species, but this project will focus mainly on these two species, plus any others in the Hakea sericea (Needlebush) group invasive in the Cape and Portugal (and New Zealand).
Other members of the group (predominantly from the eastern states of Australia. are
. Hakea actites,
. H. constablei,
. H. decurrens (P),
. H. gibbosa (C, NZ)
. H. kippistiana,
. H. leucoptera,
. H. lissosperma,
. H. macraeana,
. H. macrorrhyncha,
. H. ochroptera,
. H. sericea (C, NZ, P?)
. H. tephrosperma, .

Posted on June 16, 2021 07:23 AM by tonyrebelo