Unknown weed

[Hoy]

Nobody has been able to identify this weed.

http://www.biologforeningen.org/enbiolog/topic.asp?TOPIC_ID=46214


Any sugestions?

[Maggi Young]

Sure looks like something I should be able to  recognise!   Quite tall though - it was making me think of something smaller - related to sea samphire ( can't remember the proper name of that now!!) but this is shrubby and much too tall 

[Jupiter]

I know a lot of weeds from around here but that's nothing I've ever seen before. You need someone to go through the keys and use the floral formulas to get it down to family, and then pull up a list of genera and work through them. SHouldn't be too hard if you have good clear pictures of the flowers.

[Afloden]

Iit looks a lot like Amaranthaceae (including Chenopodiaceae).  And since the inquirer says it has a sweetish odor I am inclined to think it is Dysphania (formerly Chenopodium). A species D. ambrosioides is used in Mexican cooking and imparts a distinctive flavor. In my area it is a weed that can persist in disturbed dry areas.

[Jupiter]

I didn't know Chenopodium ambrosioides had been reclassified... interesting. I disagree with that guess though... I don't see the resemblance.

[Afloden]

My first guess is still Amaranthaceae (the former Chenopodiaceae part of it). I agree it does not look typical, or much like ambrosioides though.

A nice image of the perianth would be great, but what is there looks like its just a calyx and an immature single-seeded (?) fruit forming.

[Maggi Young]

A few suggestions :

Neokochia americana
Salsola kali
Henonia scoparia
Bassia laniflora

[Hoy]

Thanks for your suggestions although I don't think any quite fits.
The "seedpods" forming are actually very tiny flower buds, probably too late to open before winter. I have not seen it myself though.

Look at the leaves. They consist of 5 "threads".

[Jupiter]

possibly asteraceae .. tagetes?

[GordonT]

Thanks for your suggestions although I don't think any quite fits.
The "seedpods" forming are actually very tiny flower buds, probably too late to open before winter. I have not seen it myself though.

Look at the leaves. They consist of 5 "threads".

The leaves suggest to me that it might be a species of Galium. It is only a guess, hopefully someone will be able to narrow it down for you

[johnralphcarpenter]

Haven't a clue really, but as it is aromatic, could it be an Artemisia?

[Tiggrx]

It could be one of the various forms of Artemisia campestris.

[Hoy]

Artemisia campestris is not a bad idea. One of the better suggestions has been Artemisisa abrotanum.

[Anthony Darby]

Any ideas what this weed growing on the local football pitch is? A neighbour, in bare feet, walked his dog to the middle of one of the pitches last week and then realised he could walk no further due to the thorny nature of the plants' seeds. He eventually managed to get to the edge by walking on the white pitch lines. The pitches are lined for touch (and tag) rugby, and many players go barefoot. Not this season, I suspect, but fall and you know about it! I have never seen anything resembling a flower. I gently pressed my hand onto a plant and the thorny seeds took a while to remove, some leaving their thorns behind! 

[Anthony Darby]

A little bit of research has answered my own question It is Onehunga weed (Soliva sessilis). Named after the locality in Auckland where this weed was first seen, Onehunga weed is a annual weed with a very small root system. The seeds are very distinctive with their sharp spines (prickles) which readily attach to bare feet(!) in summer. Onehunga weed is generally found throughout the North Island. It often invades in autumn in turf which has bare patches following hot dry summer. It produces seeds and dies the following spring – summer. It's also called bindi weed and is native to South America.