Another weed on the streets

In addition to the common and widespread weeds around Broome, e.g.
Neem (Azadirachta indica),
Coffee Bush (Leucaena leucocephala),
Merremia (Merremia dissecta & M. aegyptia),
Buffel Grass (Cenchrus ciliaris),
Birdwood Grass (Cenchrus setiger),
Caltrop (Tribulus terrestris),
Hyptis/Mint Weed (Hyptis suaveolens) and
Siratro (Macroptilium atropurpureum),

- there are some less common and not so obvious weeds, like Coffee Senna (Senna occidentalis).

This is a small shrub that has pointy leaves with a distinctive smell (described as acrid or foetid) when crushed. The seed pods are long and thin and each one contains a row of about 30 seeds. The yellow flowers have five petals.

Coffee Senna is a declared noxious weed in the Northern Territory. If we remove it now, maybe we can prevent it becoming a major problem in the Kimberley. It is a small plant so generally it is possible to just pull it out.

Around Broome it seems to be present mostly in the drains and ditches. The drains are a bit of a major artery for weeds and certainly should be a priority for any weed control campaign.

Senna occ weed cut lofi     Senna occ weed pods cut lofi

The leaves and seedpods of Coffee Senna.

 

A weed or not ??

Sometimes it is hard to tell if a plant is a weed or a native. There are some natives that are quite weedy, with the ability to colonise open spaces and disturbed areas, including road verges. An example is Tickweed (Cleome viscosa), which is a widespread herb or forb with yellow flowers. It has sticky-hairy leaves and stems and grows to about 80 cm in height. It has been doing particularly well this wet season.

Here are some pictures to help you identify it:

IMG_0309 Cleome cut lofi

IMG_0310 Cleome leaves cut lofi

IMG_0317 Cleome bits cut lofi