Urochloa occidentalis

Urochloa occidentalis (C.A.Gardner
& C.E.Hubb.) B.K.Simon ms. Hooker's Icon. Pl. 3363 (1938).

Classification. (GPWG 2001) : Subfamily Panicoideae. Paniceae.

Basionym and/or
Replacement Name:
C.A. Gardner & C.E. Hubb., Hooker's Icon. Pl. 4:
pl. 3363, p. 1 (1938).

Type of Basionym or
Protologue Information
: HT: Gardner
, Australia: Western Australia: Wandagee Station (K; IT: PERTH).

Recent synonyms: Urochloa gilesii subsp. occidentalis.

Key references
(books and floras):
[1952] C.A.Gardner, Flora of Western
1 Gramineae (236 as Brachiaria),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia
(as Brachiaria).

[1952] C.A.Gardner, Flora of Western
1 Gramineae (233, Pl.69 as Brachiaria).

Habit. Annual.
Culms decumbent, stature slender to delicate, 10–30 cm tall, 3–6 -noded.
Mid-culm internodes glabrous. Mid-culm nodes pubescent or bearded. Lateral
branches simple or sparsely branched. Leaf-sheaths glabrous on surface or
hairy. Ligule a fringed membrane, a ciliolate membrane, truncate. Leaf-blades
linear or lanceolate, 1.5–5.5 cm long, 4–9 mm wide. Leaf-blade surface glabrous
or indumented.

Inflorescence compound, a panicle of racemes. Racemes 3–5, erect, 3–5 cm long,
2–3 mm wide. Central inflorescence axis 2–4 cm long.

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, ovate, dorsally
compressed, 3–3.8 mm long.

Glumes. Glumes
dissimilar, thinner than fertile lemma. Lower glume ovate, hyaline, without
keels, 1–3 -nerved. Upper glume ovate, membranous, without keels, 7 -nerved. Florets.
Basal sterile florets 1, male or barren, with palea. Lemma of lower sterile
floret 100 % of length of spikelet, membranous, 5–7 -nerved.

Fertile lemma 2.3–2.5
mm long, without keel. Lemma apex mucronate. Median (principal) awn 0.2–0.4 mm
long overall. Palea without keels. Anthers 3. Grain 1.5 mm long.

: Australasia.

: Western Australia.

Western Australia: Dampier.
Fortescue, Carnarvon.

Notes. W.A. In
arid and semi-arid low woodlands, acacia shrublands, arid tussock grasslands,
and arid hummock grasslands. Flowers Feb.-Oct.

Infra-specific taxa: var. occidentalis, var. ciliata  .

Spikelets glabrous        U. occidentalis var. occidentalis    

Spikelets hairy              U. occidentalis var. ciliata      

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