Digitaria orbata Hughes

Map

Spikelets

Description

Nodes on erect culm, 3–5. Mid-culm nodes glabrous (setaceous hairs occasionally present on lower nodes). Axillary inflorescences normally absent from lower nodes. Midculm leaf sheath glabrous. Mid-culm leaf blade 60–250 mm long. Mid-culm leaf blade 1.8–5.5 mm wide (average 3.0). Adaxial surface of leaf blade glabrous (nerves scabrous). Spicules well developed on leaf margins to poorly developed on leaf margins. Papillose Based hairs absent or rare in throat of collar region. Ligule 1.6–4 mm long (average 2.4). Lowermost primary branch 70–160 mm long. Pronounced spicules present on margins of primary branches. Lowermost pulvinus glabrous or hairs shorter than 0.4 mm long. Spikelets imbricate to not imbricate. Spikelets elliptic (approaching obovate). Spikelets 1.3–1.8 mm long (average 1.6). Spikelets 0.47–0.8 mm wide (average 0.70). First glume 0–0.15 mm long (mostly absent). Second glume 0.2–0.6 mm long (average 0.4). Second glume glabrous. Nerves on second glume, 0 (not distinctly nerved). Ratio of second glume length to spikelet length, 0.12–0.34 (mostly under 0.25). Lower lemma 1.1–1.6 mm long. Lower lemma shorter than upper lemma (tip of grain protruding). Nerves of lower lemma anastomosing apically. Nerves on lower lemma, 3–5 (mostly 3). Nerves of lower lemma of lowermost spikelet per node spaced to produce a relatively wide first interspace and narrow second interspace; or equidistant. Lower lemma with scattered fine pubescence to glabrous. Upper lemma muricate at maturity, papillae pronounced. Upper lemma acute.
(Description source: Webster, R.D. 1983. A revision of the genus Digitaria Haller (Paniceae: Poaceae) in Australia. Brunonia 6(2): 131–216. https://doi.org/10.1071/BRU9830131 )