Eriachne basalis M.
Lazarides. Austral. Syst. Bot.
8: 369 (1995).
Classification. (GPWG 2001) : Subfamily
Micrairoideae. Eriachneae.
Type of Basionym or
Protologue Information: Australia: Northern Teritory: Darwin and Gulf
District: on Nutwood Downs Station, 16.03S 134.18E, 2 MAy 1947, S.T. Blake
17597 (HT: CANB; IT: BRI, CANB).
Key references
(books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia.
Illustrations:
[2005] K.Mallet (ed.), Flora of Australia 44B: Poaceae 3 (Fig.
23A-B).
Habit. Annual.
Culms erect or geniculately ascending, 35–60 cm tall. Mid-culm nodes glabrous.
Lateral branches simple. Ligule a fringe of hairs, 0.3–0.6 mm long. Leaf-blades
involute or convolute, 10–20 cm long, 2–3 mm wide. Leaf-blade surface smooth,
glabrous or indumented.
Inflorescence.
Inflorescence compound, a panicle. Panicle oblong, 10–12 cm long, 3–5 cm wide.
Spikelets.
Spikelets pedicelled. Fertile spikelets 2-flowered, both fertile, comprising 2
fertile floret(s), without rachilla extension, ovate, laterally compressed,
5–5.5 mm long.
Glumes.
Glumes similar, thinner than fertile lemma. Lower glume elliptic or oblong,
membranous, much thinner on margins, without keels, 11–13 -nerved. Lower glume
surface glabrous. Lower glume apex muticous. Upper glume elliptic or oblong,
4.8–8 mm long, membranous, without keels, 11–13 -nerved. Upper glume surface
glabrous. Upper glume apex muticous.
Florets.
Fertile lemma 5–5.5 mm long, without keel, 5 -nerved. Lemma surface indumented.
Lemma apex awned, 1 -awned. Median (principal) awn 18 mm long overall. Palea 2
-nerved. Palea apex dentate. Anthers 3. Grain 2 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Northern Territory, Queensland.
Northern Territory:
Darwin & Gulf. Queensland: Cook.
Notes.
Distinguishing characters include vesicular leaf blades, the presence of
axillary spikelets and racemes, glabrous smooth many-nerved acuminate glumes,
florets shorter than glumes with appressed lemma and palea, bearded callus with
flattened glossy tip, grooveless thickly nerved lemmas, recurved scabrous
partly flattened and grooved awn, beaked bicuspidulate palea, and cuneate
truncate flattened caryopsis. E. basalis is allied to E. burkittii,
but differs by its annual (not perennial) habit, acuminately tapered (not
abruptly narrowed) glumes, the absence of a pseudo-articulation at the base of
the lemma awn, the absence of hyaline wings on the palea flaps and the presence
of reduced panicles and solitary spikelets in the basal axils. Although the
lemma in E. basalis may be depressed between the thick nerves, there is
no distinct groove near each margin as in E. burkittii. The dense cover
of vesicles on the leaf blades is also a distinctive feature, which is lacking
in E. burkittii except for a few specimens chiefly from Qld.
Endemic.
Near 16ºS in Qld and N.T. Seasonally wet depressions, pools and damp places,
often in heavy-textured soils, in association with open forests of Eucalyptus
and Melaleuca spp. Flowers and fruits Apr.-June (autumn and
early-winter).
