Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Subfamily: Panicoideae
Tribe: Paniceae
Genus: Paspalum
Species: P. dilatatum
Botanical name: Paspalum dilatatum
Common name: Paspalum, Dallis grass, Dallisgrass, Sticky heads.
Paspalum dilatatum is a perennial broadleaf grass weed which has very short stout rhizomes, which join plants together and spreading outwards to form dense clumps. It grows decumbent in a mat or erect to well over 1 m tall. The leaves are mostly hairless, growing up to 35 cm long and one wide. The inflorescence is divided into a few branches lined neatly with bead-like pairs of green to purple spikelets.
It is native to Brazil and Argentina, but it is known throughout the world as an introduced species and at times a common weed. Its rapid growth and spreading rhizomes make it an invasive pest in some areas. It is present in the southern half of North America, southern Europe, much of Africa, Australia, New Zealand, and many tropical and subtropical areas. A very common weed of gardens, lawns, footpaths, parks, roadsides, disturbed sites, waste areas, closed forests, open woodlands, crops and pastures in tropical, sub-tropical and temperate regions. It is mainly a problem in turf, as it forms unsightly clumps in lawns.
A photo of individual flowers, or spikelets
In the picture below the items looking like black butterflies dangling on white threads are pollen-producing anthers, and the small black tree-like structures issuing from the tops of florets are pollen-catching stigmas.
Thanks to Wikipedia for text and information:
https://creativecommons.org/licenses/by-sa/3.0/