Andropogon

Andropogon* L.,. Sp. Pl. 1045 (1753).

Derivation:.
From Greek aner (man) and pogon (beard), alluding to the awns or
to the long hairs on the raceme internodes and pedicels.

Key references
(keys and floras):
. J.W.Vickery, Flora of New South Wales, Gramineae
19: 50–51 (1961); E.E.Henty, Manual Grasses New Guinea 28 (1969);
M.Lazarides, Tropical Grasses S.E.Asia 18 (1980); J.C.Tothill and
J.B.Hacker, Grasses of Southern Queensland 98–99 (1983); B.K.Simon, Key
to Australian Grasses
66 (1993); S.W.L.Jacobs and C.A.Wall, Flora of New
South Wales
4: 443–444 (1993); N.G.Walsh, Flora of Victoria 2:
623–624 (1994); E.Edgar and H.E.Connor, Flora of New Zealand 5: 600–601
(2000); D.Sharp and B.K.Simon, AusGrass (2002); S.W.L.Jacobs,
R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th Ed,
122 (2008).

W.D.Clayton &
S.A.Renvoize, Genera Graminum (1986), genus (606).

Naturalised. About 100
species, from tropical regions. 3 species in Australia, WA, NT, Qld, and NSW.
Also New Guinea and New Zealand.

Habit. Annual
or perennial, rhizomatous or tufted or decumbent. Leaf blades broad or narrow.
Ligule an unfringed membrane to a fringed membrane.

Inflorescence.
Inflorescence of spicate main branches or paniculate (usually with paired or
digitate racemes, these often spatheate and aggregated into false panicles), a
spatheathe panicle, usually spatheate, racemes paired or in clusters, not in
tight heads, a compound pseudo-inflorescence (often) or not a compound
pseudo-inflorescence. Spikelet-bearing axes racemes, with heteromorphic
spikelets, paired (nearly always), disarticulating at joints. Internodes
densely long-hairy (plumose) or somewhat hairy (ciliate) or glabrous (rarely).

Spikelets.
Spikelets laterally compressed or subterete or dorsally compressed, 2 flowered,
with 1 fertile floret, awned, paired, sessile and pedicelled, in
pedicelled/sessile combinations; sessile spikelet with lower incomplete floret.
Fertile spikelets falling with glumes.

Glumes. Glumes
more or less equal, long relative to adjacent lemmas, hairy or hairless, awned
or awnless (upper glume sometimes aristate), dissimilar (subleathery to
membranous, the lower flat, concave or canaliculate on the back, its margins
folded and 2-keeled, the upper naviculate, carinate above). Lower glume
two-keeled, flattened on back to sulcate on back, relatively smooth, 1–11
nerved (sometimes lacking the midnerve). Upper glume 1–3 nerved.

Florets. Lower
incomplete floret(s) sterile. Lemmas awnless, 2 nerved, more or less equalling
fertile lemmas to exceeding fertile lemmas, less firm than fertile lemmas to
similar in texture to fertile lemmas (hyaline), not becoming indurated. Fertile
florets 1. Lemmas less firm than glumes (hyaline to firm, sometimes
substipitate beneath the awn), not becoming indurated, incised (usually bifid),
awned, 1–3 nerved, hairy or glabrous (often ciliate or ciliolate). Awns 1, from
a sinus, geniculate, hairless (glabrous) or hairy (puberulous), about as long
as body of lemma to much longer than body of lemma. Palea very reduced
(hyaline), nerveless. Callus short, blunt. Lodicules 2. Stamens 1–3. Grain
small, compressed laterally or compressed dorsiventrally or terete (subterete
to planoconvex). Hilum short. Embryo large. Pedicels free of rachis. Pedicelled
spikelets present or absent, similar in shape to sessile spikelet, sterile or
male.

Kranz Anatomy.
C4, biochemical type NADP-ME (3 species).

2n = 20,
40, 60, 100, 120, and 180, 2–18 ploid, commonly adventive.

Habitat.
Mesophytic, xerophytic. Mostly savanna, some in tropical highlands.

Classification.
Panicoideae; Andropogoneae.

Notes. The
terete and often fairly long raceme-bases help to distinguish Andropogon
from its neighbours (Clayton and Renvoize, 1986).

Types Species. A.
distachyos
L.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

AVH 2011

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith