Etymology
Tribulus from the Greek 'tribolos' meaning water-chestnut and translated into Latin as 'tribulos' which originally meant the caltrop, a 4-pointed military instrument, employed to lame advancing cavalry, and the name also applied to Tribulus terrestris. Micrococcus from Latin meaning small and spherical; possible referring to the small round fruit.
Distribution and status
Found in the far north-western part of South Australia, growing on clay and loam soils, and disturbed sites. Also found in the Northern Territory, Queensland and New South Wales. Native. Uncommon in South Australia. Uncommon in the Northern Territory. Common in the other states.
Herbarium region: North Western
NRM region: Alinytjara Wilurara
AVH map: SA distribution map (external link)
Plant description
Herb with prostrate to shortly ascending branches to more than 1 m long. Leaves opposite each other with 4-7 leaflets each. Flowers yellow with 5 petals to 15 mm long. Flowering possibly all year round depending on rainfall. Fruits are round hairy woody ball with 5 segments to 5 mm long, each with poorly developed spines, often with 2 short divergent spines pointing up. Seeds are contained within the woody fruit. Seed embryo type is spatulate fully developed.
Seed collection and propagation
Collect possibly all year round depending on rainfall events. Collect fruits that are hard and turning brown. Some fruits maybe split and laying on the ground. Be careful when collecting as the fruits are spiny. No further cleaning is required if only fruits are collected. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place. Seed viability is usually high. This species have physical and physiological dormancies that needs to be overcome for the seed to germinate.