Cyperus involucratus (CYPERACEAE) Umbrella Sedge

Weeds to Whack

An escaped garden plant native to Africa still favoured in gardens throughout the catchment as an attractive ornamental. It has become a fast-growing weed infesting damp areas, particularly creeks. It has leaves which are reduced to sheaths and stems to 120 cm. The seed heads have bracts (leaf-like growths) in a whorl, spreading like an umbrella, hence the common name. These large leafy bracts are often mistakenly assumed to be leaves. Hairless, rigid, slightly ridged stems to 5 mm thick are three-angled or almost cylindrical in cross-section. The seed head (inflorescence) has about eight stalks (5-10 cm long) radiating from the top of the stem. Flower spikelets are initially light green in colour, but turn reddish-brown as they mature. Yellowish, oval-shaped seeds are triangular in cross-section.
Photo: Matt Tomkins