Yakirra nulla Lazarides &
R.D.Webster. Brunonia 7: 295
(1985).
Classification. (GPWG 2001) : Subfamily
Panicoideae. Paniceae.
Type of Basionym or
Protologue Information: Australia:
Northern Territory:
Darwin & Gulf District: ca. 8 mi NE of Adelaide River township, 17 Mar
1965, Lazarides & Adams 262 (HT: CANB; IT: K, L, NT).
Derivation:
from the Latin nullus (nothing). Apex of the stipe lacks appendages.
Habit. Annual
or perennial. Culms erect or decumbent, 50–60(–100) cm tall, 4–6 -noded.
Mid-culm internodes hollow, glabrous or hirsute. Mid-culm nodes glabrous or
pubescent. Lateral branches sparsely branched. Leaf-sheaths hairy. Ligule a
fringe of hairs, 0.5–2 mm long. Leaf-blades 3–8(–17) cm long, 2–10 mm wide.
Leaf-blade surface scabrous, glabrous or indumented.
Inflorescence.
Inflorescence compound, a panicle. Panicle ovate, 5–23 cm long, 4–12 cm wide,
contracted about primary branches or with spikelets clustered towards branch
tips.
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
oblanceolate, dorsally compressed, 3.8–5.1 mm long. Rhachilla internodes
elongated between glumes.
Glumes. Glumes
dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without
keels, 3–5 -nerved. Upper glume elliptic, 4.1–5.1 mm long, membranous, without
keels, 7 -nerved. Florets. Basal sterile florets 1, barren, with palea
or without significant palea. Lemma of lower sterile floret 100 % of length of
spikelet, membranous, 5 -nerved.
Fertile lemma 2.5–3.8
mm long, without keel, 7 -nerved. Lodicules absent or vestigial. Anthers 3.
Grain 1.7 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Northern Territory.
Northern Territory: Darwin &
Gulf.
Notes.
Similar to the typical form of Y. pauciflora but easily distinguished by
the absence of lateral appendages at the apex of the swollen rachilla.
Restricted to a
relatively small area E and SE of Darwin. N.T. In tropical and subtropical
sub-humid woodlands and coastal grasslands. Flowers Feb.-May.
