Brachiaria plantaginea

Scientific Name	Brachiaria plantaginea (Link) Hitchc.
Synonyms	Urochloa plantaginea (Link) R.D. Webster,
Common Names	English: Alexandergrass, Plantain signalgrass; Portuguese: Capim-marmelada; Spanish: Braquipará
Description	Annual grass.

Characteristic Features

The leaf blades narrower than Panicum adspersum (Broadleaf Panicum) lighter colored, leaf margins not "wavy".

Stems

20-100 cm (7.87 - 39.37 inch), decumbent, geniculate, branching and rooting at the lower nodes; nodes glabrous.

Leaves

Sheaths mostly glabrous, except the margins ciliate, with papillose-based hairs.
Ligules 0.5-1.5 mm (0.019 - 0.059 inch).
Blades 3-21 cm (1.18 - 8.27 inch) long, 6-20 mm (0.24 - 0.78 inch) wide, glabrous, bases subcordate to cordate, clasping the stems.
Margins sometimes ciliate basally.

Flowers

Inflorescence composed of racemes. Racemes 2-8; borne along a central axis; unilateral; 2-11 cm (0.78 - 4.33 inch) long. Central inflorescence axis 10-20 cm (3.93 - 7.87 inch) long.
Rhachis broadly winged; with sharp-edged midrib; 1-2 mm (0.039 - 0.078 inch) wide; scabrous on margins.
Spikelet packing adaxial; regular; 2 -rowed. Spikelets ascending; solitary.
Fertile spikelets pedicelled.
Pedicels oblong; 0.5 mm (0.019 inch) long.
Fertile spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; compressed slightly; acute; 4-5.5 mm (0.16 - 0.22 inch) long; falling entire.
Rhachilla internodes elongated between glumes.
Glumes dissimilar; reaching apex of florets; thinner than fertile lemma.
Lower glume ovate; clasping; 0.25-0.33 times length of spikelet; membranous; without keels; 3-5 -veined. Lower glume apex obtuse, or acute.
Upper glume ovate; 1 times length of spikelet; membranous; without keels; 5-7 -veined. Upper glume apex acute.
Basal sterile florets barren; with palea.
Lemma of lower sterile floret similar to upper glume; ovate; 1 times length of spikelet; membranous; 5 -veined; acute. Fertile lemma ovate; 3.5-5 mm (0.14 - 0.19 inch) long; indurate; without keel. Lemma surface granulose; unwrinkled or rugulose. Lemma margins involute. Lemma apex obtuse.
Palea involute; indurate; without keels. Palea surface granular, or rugose.

Flowering Period

Summer.

Fruit

Caryopsis.

Seeds

Germination in spring.

Viability Of Seeds

Short lived seed bank, seeds viability less than 5 years.

Propagation

By seeds.

Habitat

Agricultural sites, disturbed areas.

Soil

Loose sand and loam soils.

Agricultural Importance

B. plantaginea is a major weed of soybean in Brazil mainly grown under reduced tillage practices. It is very competitive and a prolific seed producer.

Integrated Crop Management

Deep tillage practices and dense crop stands efficiently suppress this weed.