Plantinvasivekruger - Poaceae - Paspalum urvillei Steud.

PASUR

Poaceae

Paspalum urvillei Steud.

P. urvillei is a perennial grass that grows in large clumps, rhizomatous, 60 to 250 cm high. Culm is erect and not hairy, little branched. The leaves are linear, 15 to 50 cm long. Only the base of the plant carries bristles. The ligule is membranous and fringed. Inflorescence formed by 10-20 upright spike like racemes, 5 to 12 cm long. The subsessile spikelets fit by pairs in 4 series on the underside of the rachis of the raceme. The spikelet is oval with acute apex, long hairy, 1.2 to 1.5 mm long .

Prefoliation is coiled (convolute). The first sheaths are generally of a purple color and very hairy. The ligule is membranous, acute and translucent. The leaf blade is linear lanceolate with a prominent midrib on the underside.

Upright grass. It is a plant from 90 to 250 cm in height that forms dense clumps, rhizomatous.

Roots fasciculate and fibrous with short rhizomes. It can go to 30 cm deep.

Culm cylindrical or slightly compressed 5 mm thick, almond green. It is glabrous, usually simple or sometimes branched. The nodes are dark and hispid, with short white hairs.

Leaves are alternate, simple. The base of the plant with numerous leaves. Lower sheaths are generally purple colored and covered with white hairs, while the sheaths of the top, are green and little hairy. Membranous ligule 8 mm in height is accompanied by a ring of hairs long and rigid. The blade is linear lanceolate, the apex acute, 80 cm long and 2 cm wide. It is glabrous on the underside. The midrib channeled on the upper surface and protruding on the lower surface. The lamina is green or with purple marks.

Inflorescence an erect panicle 14-45 cm long consisting of 6-25 racemes irregularly distributed at the top of the stem and raised vertically or obliquely. Lower racemes can measure 14 cm while the upper are shorter. The rachis is trigonous with finely scabrous edges.

The spikelets are shortly stalked and are arranged in pairs on four lines along the rachis. They are oval or lanceolate with acuminate apex. They are 2.7 mm long and 1.2 to 1.5 mm wide and the bristles are about 1 mm long. The lower glume is absent. The upper glume, covered with white hair, is oval and apiculate, with three ribs. The bottom flower is sterile and lemma is similar to the upper glume. The top flower is fertile, the lemma is oval, obtuse, glabrous, 2 mm long.

Caryopsis oval, 1.8 to 2 mm long. The tegument is smooth and shiny.

P. urvillei is a perennial plant that reproduces by seeds or by division of rhizomes.

Le Bourgeois T, Carrara A, Dodet M, Dogley W, Gaungoo A, Grard P, Ibrahim Y, Jeuffrault E, Lebreton G, Poilecot P, Prosperi J, Randriamampianina JA, Andrianaivo AP, Théveny F (2008) Advent-OI : Principales adventices des îles du sud-ouest de l'Océan Indien. V.1.0, Cirad, Montpellier, France,

http://idao.cirad.fr/SpecieSheet?sheet=adventoi/especes/p/pasur/pasur_fr.html