Paspalum mandiocanum Trin., Poaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Risk assessment results:  Risk assessment of Paspalum mandiocanum from the Government of Queensland, Australia (PDF format)

Common name(s): [more details]

English: broad-leafed paspalum

Habit:  grass

Description:  "Perennial; caespitose. Culms decumbent; 45-125 cm long; without nodal roots, or rooting from lower nodes. Culm-internodes distally glabrous. Leaf-sheaths keeled. Ligule an eciliate membrane. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 10-30 cm long; 8-17 mm wide. Leaf-blade surface glabrous. Leaf-blade margins ciliate. Leaf-blade apex acute.  Inflorescence composed of racemes. Racemes 4-6; borne along a central axis; unilateral; 3-9 cm long. Rhachis angular; 1 mm wide. Spikelet packing 4 -rowed. Spikelets in pairs. Fertile spikelets pedicelled. Pedicels oblong. Fertile spikelets: Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; plano-convex; 2-2.1 mm long; 1.5 mm wide; falling entire. Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute. Florets: Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma elliptic; 2-2.1 mm long; indurate; pallid; without keel. Lemma margins involute. Palea involute; indurate. Flower: Anthers 3. Fruit: Caryopsis with adherent pericarp"  (Clayton et al., 2002).

Habitat/ecology:  "Broad-leafed paspalum is an unpalatable, introduced grass which invades cattle and horse pastures by out-competing and replacing palatable native pasture species. It can out-compete the native pasture grasses because it is a hardy, adaptable plant. It tolerates both dense shade and drought conditions, grows quickly (particularly after rainfall), smothers less competitive grasses by spreading horizontally, produces a large number of seeds and has a high rate of germination.  Plants grow in open pasture, along roadside verges, in bush margins but also in deeply-shaded sections of forest." (Queensland Government, 2008 [see also later [2016] version])

Propagation:  Seed

Native range:  Southern Brazil; Argentina, Paraguay and Uruguay (GRIN).

Presence:

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Queensland	introduced invasive	Queensland [Australia] Government (2008)

Control: 

Physical:  "Seedlings and smaller plants can be hand-pulled, bagged and composted or disposed of at the local garbage dump. Wear gloves, as the leaves and seed heads can cause skin irritation."

Chemical:  "Chemical control, such as foliar spray, may be required for larger infestations of broad-leafed paspalum. In this case, we recommend using a glyphosate 360 g/L herbicide (e.g. Weedmaster Duo®) at a rate of 10 ml per 1 L of water. Take care however, as the herbicides will damage other plants (not broad-leafed paspalum) if they are accidentally sprayed. Spray in spring when the plants are actively growing." (Queensland Government, 2008 [see also later [2016] version])