What Does It Look Like?
What is it?
Narrow Kernel Espartillo (Amelichloa brachychaeta) is a perennial (long lived) tussock forming grass with upright stems growing 40–100 cm tall. The leaf sheaths are hairless on the surface, with hairy outer margins. A small membranous structure (ligule) is present at the base of each leaf blade, which is 0.1–0.5 mm long, and has an abruptly flattened (truncate) or obtuse tip, with tufted hairs on each side. The leaf blades are 8–35 cm long, 0.5–3 mm wide, thread-like (filiform), and can be inwardly rolled (involute), flattened, or outwardly rolled (convolute). The leaf blade surface is rough and hairless, and its margins are lined with small hairs (ciliate) and hairy at the base (Sharp & Simon 2002).
Narrow Kernel Espartillo has two types of seed-head. The more obvious seed-heads are elongated clusters (panicles) found towards the top of the plant, that are 10–25 cm long, and consist of widely spaced few-flowered branches. The solitary spikelets are 6–8 mm long, and each produces a solitary seed with a hairy base and a long, twisted bristle-like structure (awn) 12–18 mm long. The florets are cylindrical, 4–5.5 mm long. At maturity, the spikelets break up, leaving the glumes (outer spikelet bracts, or modified leaves) attached to the flower stem. A second type of inflorescence is produced within the leaf sheaths, and this consists of widely spaced greenish spikelets. The flowers within these flower-heads are self-pollinated.
The seeds are yellow-brown and somewhat rounded or oblong, 2–3 mm long and 0.9–1 mm wide, with a hairy seed coat. The self-pollinated seeds (cleistogenes) occur in both the upper and lower sheaths (Parsons & Cuthbertson 2001; Sharp & Simon 2002; Navie 2004).
For further information and assistance with identification of Narrow Kernel Espartillo, contact the herbarium in your state or territory.
Flower colour
Brown, Green
Growth form (weed type/habit)
Grass
Where it currently grows? Preferred habitat
Narrow Kernel Espartillo occurs in temperate grasslands in the Southern Hemisphere and occurs as a weed of roadsides, grasslands, stream banks, disturbed sites, waste areas and disused pastures (Parsons & Cuthbertson 2001).
Are there similar species?
Narrow Kernel Espartillo can be difficult to distinguish from Broad Kernel Espartillo (Amelichloa caudata) [as Achnatherum caudatum], with the only distinguishing features being minor differences in floral structure (Parsons & Cuthbertson 2001). Broad Kernel Espartillo has broader grains, 1–1.4 mm wide, with partially hairy seed coats (lemma). In contrast, Narrow Kernel Espartillo has narrower grains, 0.9–1 mm wide, with more densely hairy seed coats. The self-pollinated seeds (i.e., those produced within the leaf sheaths) in Broad Kernel Espartillo are produced only in the lower leaf sheaths, while those of Narrow Kernel Espartillo are produced in both upper and lower sheaths (Navie 2004).
Narrow Kernel Espartillo is also similar to several native Speargrasses (Austrostipa spp.), but can be distinguished from these species by its membranous ligules. It is also similar to a number of introduced species including Needlegrasses (Nassella spp.), Uruguayan Ricegrass (Piptochaetium montevidense) and Plumerillo (Jarava plumosa). It can be distinguished from Mexican Feathergrass (Nassella tenuissima) and Serrated Tussock (Nassella trichotoma) by its generally broader leaves (1–7 mm wide, compared to 1 mm wide) and it can be distinguished from the Needlegrasses (Nassella spp.) as its seeds do not have a crown-like structure (corona) where the awn meets the seed. Narrow Kernel Espartillo can be distinguished from Uruguayan Ricegrass by its elongated grain and from Plumerillo by the lack of a plume of hairs on the lower part of the awn (Navie 2004).
