Cyperus odoratus L.

Global description

Cyperus odoratus is a sedge growing in a large clump, the culm is trigonal, smooth with a bulbous base. The leaves are linear with a sheath as long as the blade. The inflorescence is a broad, simple or compound terminal umbel, subtended by 6-8 leafy bracts, the largest being up to 50 cm long. The inflorescence is composed of 5 to 20 primary rays which may bear a groupe spikes at the tip, or divide again into 5 to 12 shorter secondary rays bearing a small cluster of 1 to 5 spikes at the tip. The spikelet spike is oblong cylindrical with an axis of 1 to 2 cm bearing 20 to 60 filamentous, yellow, linear spikelets arranged perpendicular to the spike axis. The spikelet consists of 6 to 18 oval glumes. The style is trifid. The fruit is a trigonal obovoid achene.

General habit

Cyperus odoratus is a large sedge growing in clump, formed from 1 to a few culms and measuring 30 to 100 cm in height.

Underground system

When the plant is a vivacious, the underground system consists of short, fragrant rhizomes and fibrous fasciculated roots. When it is an annual, only the fibrous fasciculated roots are present.

Culm

The culm is trigonal, 2-5 mm in diameter, smooth with no sharp angles. It is 30 to 100 cm high. The base is widened into a pseudo-bulb.

Leaf

There are 3 to 4 leaves per culm. These have a closed sheath up to 30 cm high and a linear, flat blade with an acuminate apex, and are up to 30 cm long and 4 to 12 mm wide. Both sides are glabrous. The terminal part of the margin and the main vein on the lower side are slightly scabrous.

Inflorescence

The inflorescence is terminal, broadly corymbiform, single or multiple, and 5-20 cm in diameter. It is subtended by 6-8 leafy bracts, the largest of which are up to 50 cm long and longer than the rays of the inflorescence. At the base of the secondary rays there are also small linear leaf bracts of the same length as the secondary rays. The inflorescence consists of up to 12 rigid, slightly flattened primary rays of different lengths (up to 20 cm long). They bear a group of 3 to 5 spikelets at the top or a second level of 2 to 6 secondary rays up to 3 cm long with a small group of spikes at the top. The spike is oblong cylindrical, 2-3 cm long and 1.5 cm in diameter, consisting of 20-60 spikelets arranged perpendicular to the axis which is 1-2 cm long.

Spikelet

The spikelet is filiform, cylindrical, 10 to 25 mm long and 1 to 1.5 mm in diameter, consisting of 6 to 20 golden yellow glumes. The rachilla is articulated at the insertion of each glume and has winged edges. The glumes are oval or oval-elliptical, obtuse at the top, 2 to 3.5 mm long and 1 mm wide. They are cartilaginous with a hyaline margin. The carina is not very marked. Stamens 3, with anthers 1 mm long. Style trifid at the apex.

Fruit

The fruit is partially hidden by the winged edges of the spikelet rachilla, to which it remains attached. It is an obovoid, trigonal, cylindrical achene, 1.5-2 mm long and 0.5-0.7 mm in diameter, dark brown. The base is attenuated to a point and the apex is obtuse and apiculate, sometimes with a persistent style. The two ventral sides are identical and the dorsal side is wider. The angles are rounded.

Origin

Cyperus odoratus is a pantropical species native to tropical and subtropical regions of the American continent, the Caribbean, some African countries (especially along the West Coast from Mauritania to Angola), Madagascar, India, Southeast Asia to Queensland in Australia.

Worldwide distribution

This species has been introduced in some countries in Mediterranean Europe (Bulgaria, Spain, Italy, Romania, Yugoslavia), in Palestine and in the Pacific in the Society Islands

https://www.gbif.org/fr/species/2715219