Order: Poales Family: Cyperaceae
Water grass, highland nut sedge, papyrus, yellow nut sedge, purple nut sedge
Clove Pyrethrum Sisal hemp Strawberry
Geographical Distribution in Africa
Geographical Distribution of Dodder in Africa (red marked). Updated on 10 July 2019. Source CABI.
General Information on Disease and Damage
It is a perennial sedge that is widespread in the highlands (1200-3350 m) of East Africa. It can be a problem in pastures, and for pyrethrum and other crops, especially where there is little or no cultivation. It is propagated by rhizomes (a root-like underground stem) and tubers.
A perennial sedge localized in the uplands of Kenya and Tanzania. It is also present in Ethiopia. It is a weed of crops in the highlands. It is propagated byrhizomes and seed.
It is a stately aquatic member of the sedge family. It is a herbaceous perennial native to Africa. This tall, robust, aquatic plant can grow 4 to 5 m (13 to 16 ft) high. It forms a grass-like clump of triangular green stems that rise up from thick, woody rhizomes. Each stem is topped by a dense cluster of thin, bright green, thread-like stems around 10 to 30 cm (4 to 10 in) in length, resembling a feather duster when the plant is young. Greenish-brown flower clusters eventually appear at the ends of the rays, giving way to brown, nut-like fruits. Papyrus sedge (and its close relatives) has a very long history of use by humans, notably by the Ancient Egyptians'. It is the source of papyrus paper, parts of it can be eaten, and the highly buoyant stems can be made into boats. It is now often cultivated as an ornamental plant.
Distribution and ecology
C. esculentus is a light green perennial sedge growing to about 1 m in height with solitary stems growing from a tuber. The stems are triangular in section, and bear slender leaves 3-10 mm wide. The flowers of the plant are distinctive, with a cluster of flat oval seeds surrounded by four hanging leaf-like bracts (modified leaves from where flowers arise) positioned 90 degrees from each other. The plant foliage is very tough and fibrous, and is often mistaken for a grass.
Distribution and ecology
Host range and damage
C. rotundus (Coco-grass, Purple Nut Sedge or Red Nut Sedge):
C. rotundus is a perennial plant that may reach a height of up to 40 cm. The names "nut grass" and "nut sedge" (shared with the related species Cyperus esculentus) are derived from its tubers, that somewhat resemble nuts, although botanically they have nothing to do with nuts.
As in other Cyperaceae, the leaves sprout in ranks of three from the base of the plant. The flower stems have a triangular cross-section. The flower is bisexual, reddish-brown to purplish-brown. The fruit is a three-angled achene (small, dry, not opening when ripe, one-seeded).
The root system of a young plant initially forms white, fleshy rhizomes. Some rhizomes grow upward in the soil, and then form a bulb-like structure from which new shoots and roots grow, and from the new roots, new rhizomes grow. Other rhizomes grow horizontally or downward, and form dark reddish-brown tubers or chains of tubers.
Secondary hosts: Syzygium aromaticum (clove), Cocos nucifera (coconut), Allium cepa (onion), Capsicum annuum (bell pepper), Fragaria sp. (strawberry), Agave sisalana (sisal hemp), Sorghum, Glycine max (soybean), Camellia sinensis (tea),Lycopersicon esculentum (tomato), Triticum (wheats).
Biology and Ecology of Sedges
Life Cycle of Purple Nut Sedge (Cyperus rotundus)
Pest and Disease Management
Pest and disease management: General illustration of the concept of Infonet-Biovision
Further below you find concrete preventive and curative methods against Sedges.
Cultural and mechanical control of C. esculentus
Mechanical control of C. rotundus
Biological pest control
Information Source Links
- CAB International (2005). Crop Protection Compendium, 2005 edition. Wallingford, UK www.cabi.org
- Haines, R.H. and Lye, K.A. (1983). The Sedges and Rushes of East Africa. East African Natural History Society, Nairobi, Kenya
- Terry, P.J. and Michieka, R.W. (1987). Common Weeds of East Africa. Food and Agriculture Organization of the United Nations (FAO). ISBN: 92-5-002426-6
- Wikipedia: www.wikipedia.org/Cyperus
- www.wikipedia.org/Cyperus rotondus
- www.wikipedia.org/Cyperus esculentus
- www.wikipedia.org/Cyperus papyrus