Paspalum conjugatum P.J.Bergius
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Common name
Sour Grass
Hilo Grass
Johnson River Grass
Yellow Grass
Derivation
Paspalum L., Syst. Nat. 10th edn, 855 (1759); from the Greek paspalos
(a kind of millet).
conjugatum- from the Latin conjugo (yoke together). Inflorescence branches paired.
Published in
Acta Helv. Phys.-Math .7: 129 (1762).
Habit
Perennial. Cataphylls present. Stolons present, with alternating elongated and
bunched internodes. Culms erect, 20100 cm tall, 310-noded. Mid-culm
nodes glabrous. Lateral branches sparsely branched. Leaf-sheaths outer margin
glabrous. Leaf-sheath auricles absent. Ligule an eciliate membrane, 0.31.5
mm long. Leaf-blades linear or lanceolate, 420 cm long, 515 mm wide.
Leaf-blade surface smooth, glabrous or hairy.
Inflorescence
Inflorescence digitate, a panicle of racemes. Racemes 23, spreading, unilateral,
417 cm long, 0.81 mm wide, bearing 120250 fertile spikelets
on each. Rhachis wingless or narrowly winged or broadly winged, angular, 0.5
mm wide. Spikelet packing abaxial, regular, 2-rowed.
Spikelets
Spikelets solitary. Pedicels 0.150.3 mm long. Fertile spikelets 2-flowered,
comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla
extension, orbicular, dorsally compressed, plano-convex, obtuse, 1.21.8
mm long, falling entire.
Glumes
Glume 1 (the lower absent or obscure), thinner than fertile lemma. Upper glume
orbicular, 1.21.8 mm long, 100% of length of spikelet, hyaline or
membranous, yellow, 23-nerved. Upper glume surface glabrous. Upper glume
margins ciliate. Upper glume apex obtuse.
Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret
similar to upper glume, elliptic, 1.21.8 mm long, 100% of length of
spikelet, membranous, 2-nerved, obtuse. Fertile lemma orbicular, gibbous, 1.21.8
mm long, indurate, pallid or yellow, 3-nerved. Lemma surface striate. Lemma
margins involute. Lemma apex acute. Palea involute, cartilaginous or indurate.
Anthers 0.40.5 mm long.
Continental Distribution:
Africa, Temperate Asia, Tropical Asia, Australasia, Pacific, North America,
South America.
Australian Distribution:
Western Australia, Northern Territory, Queensland, New South Wales.
Western Australia: Gardner. Northern Territory: Darwin & Gulf. Queensland: Cook, North Kennedy, South Kennedy, Port Curtis, Wide Bay, Moreton. New South Wales: North Coast.
Classification. (GPWG
2001):
Panicoideae: Paniceae
Notes
Introduced. In tropical heaths, tropical and subtropical rain forests, and temperate
rain forests. Preferring wet roadsides or ditches and quickly spreading via
highly productive stolons. Flowers Apr.Aug.
Inflorescence (photo)
© Queensland Herbarium
Sharp 290 and Simon
by D.Sharp