Cyperus amabilis Vahl

Global description

Cyperus amabilis is a small tufted plant with short filiform linear leaves in the shape of a flared gutter. The inflorescence develops into umbellules umbel. Each ray carries at the top a bundle of filiform and flat spikelets of golden brown to ferruginous red color. The glume, 1.5 mm long, is mucronate. The achene is an elongated and trigonal, shorter than the glume and surmounted by a trifid style beyond the glume.

First leaves

The first leaves develop in small tuft. They are linear and measure 2 to 5 cm long and 1 mm wide. At the base of the limb is a short sheath. The limb is gutter-shaped with slightly flared edges. The tristic arrangement of the leaves is not always easily visible at the level of the seedling.

General habit

Cyperus amabilis has a tufted habit. It does not exceed 25 cm in height and 20 cm in diameter. It is composed of many flowering axes bearing at their base short linear leaves.

Underground system

The roots are fasciculate. They are very numerous, simple and filiform.

Stem

The stems correspond to the flowering axes. They are slender, full and of triangular section with rounded corners. They are perfectly hairless and measure 10 to 20 cm high and 1 mm in diameter.

Leaf

The leaves are filiform linear. They are arranged tristically at the lower part of the flowering axes. The blade is 3 to 10 cm long and 1 to 2 mm wide. The section is gutter with slightly flared edges. Both sides are totally glabrous and bright green in color. The margin is entire. At the base of the limb is a triangular sheath 1 to 2 cm high surrounding the stem.

Inflorescence

The flowers are assembled in linear spikelets flattened 5 to 20 mm long and 1 mm wide. These spikelets are themselves grouped together in groups of 4 to 20, forming a semicircular head. At the top of the flowering axes is a cluster of spikelets surrounded by several rays 2 to 10 cm long, carrying a bundle of spikelets and possibly another level of branching. Thus, the inflorescence develops into a primary umbel carrying secondary and sometimes tertiary umbels. These rays develop at the armpit of linear bracts 1 to 4 cm long.

Spikelet

The spikelets are golden brown to ferruginous red. They carry 10 to 40 flowers arranged along the rachis alternately couplet. The glume is 1.2 to 1.5 mm long and 0.5 mm wide, it is carinated and mucronate at the top. It is crossed by a clear rib on both sides of the hull. The ovary is surmounted by a long trifid style beyond the glume.

Fruit

The fruit is a trigene achene, obpiriform elongated 0.5 mm long and 0.2 mm wide. It is reddish in color. It is surmounted by a trifid style.

https://www.gbif.org/species/2716444