Unwelcome Strangers

Unwelcome Strangers. . , What is a weed?, A weed is a plant considered to be growing 'out of place', generally with detrimental consequences. Environmental weeds invade native ecosystems, usually adversely affecting indigenous plants and animals. Weeds are also a significant problem in horticulture, agriculture and forestry., Mother's Day menace, Mother's Day 2008 an officer from the Department of Primary Industries noticed plants labelled as ornamental grasses at a major retail outlet. Suspecting they were the serious environmental weed Nassella tenuissima (Mexican Feather Grass), he purchased some plants and obtained material from the seed supplier. Plants were brought to the Herbarium to confirm their identity. Using herbarium collections and literature, RBG botanist Val Stajsic verified the plants in flower as Nassella tenuissima. However, he wasn't able to confirm the identity of plants not in flower., Enter RBG molecular systematist Dan Murphy and colleagues. They developed a DNA fingerprinting recipe to reliably distinguish Nassella tenuissima from related species of stipoid grasses. Analyses were based on herbarium specimens identified by international stipoid grass experts. After much experimentation, a new method was developed that requires only a small sample of leaf material. It is now being used to investigate other invasive grass species., This work will help to protect Australia's most threatened indigenous grasslands and will also benefit Australia's grazing industries Preventing Nassella tenuissima from becoming established in Australia will potentially save $39 million over the next 60 years.