Setaria apiculata (Scribn. & Merr.) K.Schum.

Poaceae

Schumann, K.M. (1902) Botanischer Jahresbericht [Just] 28(1): 417.

Pigeon Grass

Tufted annual with erect or geniculately ascending or decumbent, slender culms, 25-80 cm tall, firm or wiry. Nodes blackish purple and glabrous. Lateral branches branched.

Leaf-blades flat, 8-24 cm long and 2-6 mm wide, light green or glaucous, adaxial surface with very long silky hairs 3 mm lontg. Leaf-sheaths longer than adjacent culm internode, smooth or scaberulous, with glabrous outer margin. Ligule a fringe of hairs.

Inflorescence a spiciform panicle, linear in outline, 2-5 cm long. Primary panicle branches not whorled to whorled at most nodes, bearing 1 fertile spikelet on each lower branch, but sterile at the tips. Panicle axis pubescent. Peduncle scaberulous above. Spikelets subtended by 4-5 scabrid bristles. Involucral bristles persistent, 4-8 in a principal whorl, 8-12 mm long, flexible, antrorsely scaberulous, glabrous. Pedicels reduced to a stump with a cupuliform tip. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, elliptic or obovate, slightly dorsally compressed, gibbous, 3-3.4 mm long, falling entire. Glumes thinner than fertile lemma. Lower glume ovate, 1.5-2.7 mm long, more than half the length of the spikelet, membranous, 3-5-nerved. Lower glume apex acute or acuminate. Upper glume elliptic or ovate, 2.3-3.8 mm long, nearly as long as the spikelet, membranous, 5-7-nerved. Upper glume apex acuminate. Basal sterile floret 1, with palea. Lemma of lower sterile floret ovate, 2.9-4 mm long, same length than the spikelet, membranous, 5-7-nerved, with nerves meeting and uniting at apex, glabrous, acute. Fertile lemma ovate, dorsally compressed, 2.5-4 mm long, indurate, yellow or dark brown, 5-nerved. Lemma surface rugose, margins involute, apex acute or apiculate, mucronate. Palea involute, indurate, surface rugose.

Caryopsis with adherent pericarp, ovoid or orbicular, flettened on one side1.5 mm long, greenish yellow, with many transverse ridges. Hilum punctiform.

Features not available.

Occurs in WA, NT, CYP, NEQ and CEQ. Altitudinal range from near sea level to 480 m. Grows in swampy areas, damp places and along creeks in Eucalypt forest, woodland and grassland.

Chaetochloa apiculata Scribn. & Merr., United States Department of Agriculture, Division of Agrostology. Bulletin 21: 9(1900), Type: Australia. Type specimen collected by F. von Mueller, Victoria River, Queensland.