Digitaria stenostachya

Digitaria stenostachya D. K. Hughes. Bull. Misc. Inform. Kew 1923: 311 (1923).

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

Basionym and/or Replacement Name:  Panicum stenostachyum Benth., Fl. Austral. 7: 470 (1878), non Thwaites (1864).

Type of Basionym or Protologue Information: HT: F.J.H. von Mueller s.n., May 1856, Australia: Northern Australia: upper Victoria River (K; IT: L, US-733552, W).

Key references (books and floras): [1878] G.Bentham, Flora Australiensis 7 (470 as Panicum stenostachyum), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.

Habit. Annual. Culms erect or geniculately ascending or decumbent, 30–50 cm tall, 3–10 -noded. Mid-culm internodes glabrous. Mid-culm nodes glabrous. Lateral branches sparsely branched. Leaf-sheaths antrorsely scabrous, glabrous on surface. Leaf-sheath auricles absent. Ligule an eciliate membrane, 0.6–1 mm long, truncate or acute. Leaf-blades flat or conduplicate, 5–12 cm long, 1–3 mm wide. Leaf-blade surface scabrous, glabrous or indumented.

Inflorescence. Inflorescence digitate or subdigitate, with racemose branches. Racemes 2–3, 3–9 cm long, bearing 20–30 fertile spikelets on each. Central inflorescence axis 0–1.5 cm long.

Spikelets. Spikelets pedicelled, 2 in the cluster. 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, oblong, dorsally compressed, 2.5–2.75 mm long. Rhachilla internodes brief up to lowest fertile floret.

Glumes. Glumes thinner than fertile lemma. Upper glume lanceolate, 1.7–1.9 mm long, membranous, without keels, 3 -nerved. Upper glume surface indumented. Florets. Basal sterile florets 1, barren, without significant palea. Lemma of lower sterile floret 100 % of length of spikelet, membranous, 7 -nerved.

Fertile lemma 2.5–2.75 mm long, without keel. Lemma apex muticous. Lodicules present.

Continental Distribution: Australasia.

Australian Distribution: Western Australia, Northern Territory.

Northern Territory: Darwin & Gulf, Victoria River.

Notes. A morphologically unusual species showing affinities to the sections Pennatae, Heteranthae and Monodactylae.

In tropical and subtropical sub-humid woodlands. Known from four collections in the N.T., on sandstone ridges and moist sandy areas in sub-humid woodlands. Flowers Feb.-Mar.



Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith