''Digitaria insularis'' is a species of

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

commonly known as sourgrass. It is native to Central and South America and the southern parts of the United States and has been introduced into other parts of the world. It was first described by the German botanist

Friedrich Karl Georg Fedde Friedrich Karl Georg Fedde (30 June 1873, Breslau (now Wrocław) – 14 March 1942, Berlin-Dahlem) was a German botanist. Biography Fedde studied natural sciences, commencing in 1892 and graduating in 1896 in Breslau. He was a teacher in schools ...

in 1904.

Description

''Digitaria insularis'' is a tufted perennial

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennial ...

with very short, swollen rhizomes. The stems reach a height of 80–130 cm and are erect, branched from the lower and middle nodes, swollen bases, with woolly bracts, glabrous internodes and nodes. Sheaths papillose - pilose in their majority, ligule 4–6 mm long, blades linear, 20–50 cm long and 10–20 mm wide. Inflorescence 20–35 cm long, numerous clusters, 10–15 cm long, solitary triquetrous rachis of clusters, 0.4-0.7 mm wide, scabrous; spikelets lanceolate, 4.2-4.6 mm long, paired, caudate, densely covered with trichomes up to 6 mm long, brown or whitish, ranging up to 5 mm from the apex of the spikelet; lower glume triangular to ovate, to 0.6 mm long, enervate, membranous; upper glume 3.5-4.5 mm long, acute, 3-5 nerved, ciliated; inferior lemma as long as spikelet, acuminate, 7-nerved, covered with silky hairs, upper lemma 3.2-3.6 mm long, acuminate, dark brown; anthers 1-1.2 mm long.

Distribution and habitat

''Digitaria insularis'' is native to the tropical and sub-tropical Americas. It is a common species found in disturbed areas and on beaches, at an altitude of up to above sea level. In its native Brazil, Paraguay, Bolivia and Venezuela it is a pervasive

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

out of its natural habitats. It has been introduced in tropical Asia and some Pacific islands and elsewhere. In some countries into which it has been introduced such as Hawaii and Papua New Guinea, it is considered an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

References

*''This article contains material translated from the Spanish Wikipedia.'' {{Taxonbar, from=Q14834635 insularis Bunchgrasses of North America Bunchgrasses of South America Flora of Central America Grasses of Argentina Grasses of Brazil Neotropical realm flora