Panicum trichoides* Sw. Prodr. Veg.
Ind. Occ. 24 (1788).
Classification. (GPWG 2001) : Subfamily
Panicoideae. Paniceae.
Type of Basionym or
Protologue Information: LT: O.P. Swartz s.n., left-hand specimen,
Jamaica (S; ILT: US-81153 (fragm. ex S)). LT designated by Hitchcock, Contr.
U.S. Natl. Herb. 12: 140 (1908).
Key references
(books and floras): [1878] G.Bentham, Flora Australiensis 7 (485),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.
Habit. Annual.
Rhizomes absent. Stolons present. Culms erect or geniculately ascending or
decumbent, stature slender to delicate, 15–100 cm tall, 3–11 -noded. Mid-culm
internodes pubescent. Lateral branches sparsely branched. Leaf-sheaths hairy.
Leaf-sheath auricles absent. Ligule an eciliate membrane or a fringed membrane,
a ciliate membrane. Leaf-blades lanceolate or ovate, 1.5–8 cm long, 5–20 mm
wide. Leaf-blade surface smooth, indumented.
Inflorescence.
Inflorescence compound, a panicle. Panicle oblong or ovate, 4–20 cm long,
evenly furnished.
Spikelets.
Spikelets pedicelled. Fertile spikelets 2-flowered, the lower floret barren
(rarely male), the upper fertile, comprising 1 basal sterile florets,
comprising 1 fertile floret(s), without rachilla extension, elliptic or ovate,
dorsally compressed, 1–1.5 mm long. Rhachilla internodes elongated between
glumes.
Glumes. Glumes
dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without
keels, 1 -nerved. Lower glume surface indumented. Lower glume apex muticous.
Upper glume elliptic or ovate, 1–1.3 mm long, membranous, without keels, 3–5
-nerved. Upper glume surface indumented. Florets. Basal sterile florets
1, barren, without significant palea. Lemma of lower sterile floret 100 % of
length of spikelet, membranous, 3–5 -nerved, muticous.
Fertile lemma 0.8–1.3
mm long, without keel. Lemma apex muticous.
Continental
Distribution: Africa, Temperate Asia, Tropical Asia, Australasia, Pacific,
North America, and South America.
Australian
Distribution: Western Australia, Northern Territory, Queensland, Christmas
Is.
Western Australia:
Gardner. Northern Territory: Darwin & Gulf. Queensland: Cook,
Leichhardt, North Kennedy, Burke, Port Curtis.
Notes.
Diagnostic features include spikelet length, the muricate upper floret, the
acute to rounded upper glume and lower lemma with recurved margins, and the
vestigial lower palea.
Native (?). Occurs in
the Americas from Mexico to Brazil. It is widespread in tropical Asia and
introduced into tropical Africa. In tropical and subtropical rain forests,
tropical and subtropical sub-humid woodlands, and coastal grasslands. Panicum
trichoides grows well in moist, shaded forested areas at lower elevations.
Flowers Feb.-Sept.
