(Photos: E. Cousins, growth habit; http://www.dpi.nsw.gov.au/__data/assets/image/0007/199204/paspalum-190.jpg, seed head.)
This fairly common broad-leafed perennial from the Poaceae family is an exotic from South America. The plant will grow quite tall; some at Cape Jervis are up to 1m high. It grows in tussocks, with bright green, almost hairless leaves that tend to fold over near the bottom. The tussocks spread from short rhizomes underground, allowing the grass to recover quickly if grazed. Sadly for us, it is spreading into one of our good native patches at Cape Jervis. It is easily recognized from the seed heads. The purple-green seeds look like they are arranged in double rows very symmetrically along several branches, radiating out from the top of the flower stem. These are often sticky, which you will know if you play backyard cricket near them (in fact one common name for paspalum is sticky grass).
(Photos: E. Cousins; habit, closer view of leaves and fruit.)
This small creeping plant from the pea family can be used as a pasture crop, but it can become a weed in some habitats. It is a prostrate (flat to the ground) annual, though it can climb slightly through nearby plants. The multiple stems are green to slightly red, and can be up to 50cm long. The leaves occur in groups of 3 leaflets at the end of short stalks. The centre leaflet has the longest stalk (an identification key used for distinguishing medics from similar plants). Leaflets can be heart or wedge-shaped, as seen above, with finely toothed margins near the tip. Pea-like yellow flowers appear in spring, to be followed by the fruits. These are like little coiled pods, disc or barrel-shaped, 3-4mm wide, with hooked spines (see second photo) all over.
BUCKBUSH or ROLYPOLY
(Photo: E. Cousins, Cape Jervis; plant, close-up of a flower on a ridged stem)
This prickly little flowering annual can grow into a ball about knee high, bright green where a lot of the local plants are a duller colour. The hard stems are really ridged, as seen in the second photo. There you can also see the needle-like tips on the small, cylindrical leaves, making the plant feel spiky. Notice also the papery, cream disk there too? That is a fruit. It has a flattened wing all around, with 5 lobes; the fruit is protected by 3 leaves under it. The plant can break off at ground level and blow away like tumbleweed, dispersing the seeds in the fruit. These seeds then germinate from autumn to winter, with new plants flowering in spring-summer. Earlier called Salsola tragus, buckthorn has been renamed Salsola australis after some detective work by SA Herbarium experts. ‘Salsola’ itself is from the Latin word for ‘salty’.