Digitaria bicornis
(Asian crabgrass)

Preferred Common Name

• Asian crabgrass

Other Scientific Names

• Digitaria barbata Willd.
• Digitaria barbulata Desv.
• Digitaria biformis Willd.
• Digitaria commutata Schult.
• Digitaria diversiflora Swallen
• Digitaria queenslandica Henrard
• Digitaria rottleri Roem. & Schult.
• Panicum adpressum Forssk.
• Panicum adpressum Willd.
• Panicum appressum Kunth
• Panicum barbatum (Willd.) Kunth
• Panicum bicorne (Lam.) Kunth
• Panicum biforme (Willd.) Kunth
• Panicum ciliare A.Rich.
• Panicum commutatum (Schult.f.) Nees
• Panicum glaucescens Nees
• Panicum macrostachyum Hochst. Ex T.Durand & Schinz
• Panicum neesii Kunth
• Paspalum bicorne Lam.
• Syntherisma barbata (Wild.) Nash

International Common Names

• English: Asia crab grass; crab grass; finger grass; hairy finger grass; large crab grass; southern crabgrass; tropical crabgrass
• Spanish: falsa pata de gallina; horquetilla; pata de gallina; zacate seleya
• French: herbe fine; zeb fin

Local Common Names

• Brazil: capim-colchão; capim-tinga
• China: yi ma tang
• Colombia: zacate guarda rocío
• Cuba: pata de gallina
• El Salvador: zacate seleya
• Honduras: pangola criollo
• Mexico: cangrejo; zacate guarda rocío; zacate pata de gallina
• Thailand: white birdfoot grass

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Cyperales
•                         Family: Poaceae
•                             Genus: Digitaria
•                                 Species: Digitaria bicornis

Digitaria is a genus in the Poaceae with about 220 species that are distributed in the tropical, subtropical and temperate regions of the world (Vega and Rugólo de Agrasar, 2007). The common name crabgrass is applied to many species in the genus. Digitaria comes from Digitus, the Latin word for "finger", referring to the long, finger-like inflorescences produced by the grasses. The species epithet bicornis means ‘forked’ or ‘two-horned’.

The following description is from Flora of China Editorial Committee (2016):

Annual, culms decumbent, rooting at lower nodes, 30–60 cm tall. Leaf sheaths glabrous or- lower sheaths papillose­pilose; leaf blades linear, 2.5–15 × 0.2–0.9 mm, usually scabrid on both surfaces, rarely sparsely pilose; ligule 1–3.5 mm. Inflorescence digitate or subdigitate; racemes 2– 5, 4–14 cm; spikelets paired, imbricate; rachis triquetrous, ca. 1 mm wide, winged. Spikelets lanceolate, ca. 3 mm, those of a pair usually different; lower spikelet glabrous, upper spikelet pubescent; lower glume very small, almost absent or up to 0.4 mm, triangular or bifid, veinless; upper glume lanceolate, ca. 2/3 length of spikelet, 3-­veined, pilose; lower lemma as long as spikelet, 7-­veined, lower spikelet with equidistant veins, upper spikelet with wider glabrous interspaces on either side of midvein, lateral veins crowded near margins, rows of silky hairs between lateral veins, usually also setose, the hairs spreading halo-­like at maturity; upper lemma yellowish, slightly shorter than spikelet.

Information about the introduction of the species to areas outside its native range and/or its spread is not readily available. Catasús Guerra (2015) lists the species as being dispersed by wind, humans and animals. Due to the small size of the seeds it is highly probable that the species has been dispersed unintentionally as a contaminant in imported agricultural products, through soil or transported by humans. Outside its native range, there are reports of D. bicornis in Brazil by the mid 1800’s and for North America, Central America and the Caribbean in the mid to late 1800’s (Missouri Botanical Garden, 2016; New York Botanical Garden, 2016). It was recorded for the first time in Honduras in 1979 (Nelson, 1979).

Soil drainage

• free
• impeded

Soil reaction

• acid
• neutral

Soil texture

• heavy
• light
• medium

Special soil tolerances

• saline

Natural Dispersal (Non-Biotic)

D. bicornis is wind dispersed (Catasús Guerra, 2015). The unit of dispersal reported for D. bicornis and other Digitaria species is the spikelet (Vega et al., 2010).

Vector Transmission (Biotic)

The species is reported by Catasús Guerra (2015) as being dispersed by animals, but without further details.

Accidental Introduction

Anthropochory is reported by Catasús Guerra (2015) as occurring for D. bicornis without further details.

D. bicornis is one of the weeds that has caused loss of productivity in soyabean fields in Brazil (Duarte et al., 2009).

• Proved invasive outside its native range
• Has a broad native range
• Highly adaptable to different environments
• Is a habitat generalist
• Pioneering in disturbed areas
• Has high reproductive potential

• Negatively impacts agriculture

• Hybridization

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant

D. bicornis is recommended as having potential for saline wastewater purification systems for organic matter and suspended soils removal (Klomjek and Nitisoravut, 2005). It is used as forage or as a fodder for livestock (Quattrocchi, 2006; Catasús Guerra, 2015). In Colombia, it is part of the diet of the capybara, Hydrochaeris hydrochaeris (Forero-Montaña et al., 2003).