Micraira adamsii

Micraira adamsii M. Lazarides. Brunonia 2: 71 (1979).

Classification. (GPWG 2001) : Subfamily Micrairoideae. Micraireae.

Type of Basionym or Protologue Information: Australia: Northern Territory: Darwin & Gulf Distr.: 12.45S 133.20E, 20 Feb 1973, Craven 2328 (HT: CANB).

Key references (books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.

Illustrations: [2005] K.Mallet (ed.), Flora of Australia 44B: Poaceae 3 (Fig. 21G-I).

Habit. Perennial. Culms prostrate, 4–5 cm tall, 0.5 mm diam. Leaves cauline. Leaf-sheaths glabrous on surface. Ligule a fringed membrane or a fringe of hairs, a ciliate membrane, 0.3–0.5 mm long. Leaf-blades 0.7–1.6 cm long, 0.5–1.5 mm wide. Leaf-blade surface scaberulous or scabrous, glabrous or indumented.

Inflorescence. Inflorescence compound, a panicle. Panicle ovate, 1–1.5 cm long, 0.7–1.5 cm wide.

Spikelets. Spikelets pedicelled. Fertile spikelets 2-flowered, both fertile, comprising 2 fertile floret(s), without rachilla extension, oblong, laterally compressed, 0.5–1 mm long.

Glumes. Glumes similar, firmer than fertile lemma. Lower glume oblong or ovate, membranous, keeled, 1-keeled, 1 -nerved. Upper glume oblong or ovate, 0.5–1 mm long, membranous, keeled, 1-keeled, 1 -nerved. Upper glume apex entire or erose.

Florets. Fertile lemma 0.3–0.5 mm long, keeled, 0–5 -nerved. Lemma apex muticous or mucronate. Palea 2–4 -nerved. Palea apex divided to base. Lodicules absent or vestigial. Anthers 2. Grain 0.3–0.5 mm long.

Continental Distribution: Australasia.

Australian Distribution: Northern Territory.

Northern Territory: Darwin & Gulf.

Notes. Superficially, M. adamsii resembles M. subulifolia, but differs in its divided palea, fewer-nerved lemma and palea and shorter florets relative to the glumes. Like M. subulifolia, its spikelet varies in morphology (viz. glume shape and relative size, relative length of the florets, and shape, relative size and surface texture of the caryopsis), its floral bracts vary in nervation and its leaves in indumentum. When present, the lateral nerves of especially the lemma vary in number, prominence and symmetry. In indumentum, the blades of Martensz and Schodde AE 705 are almost glabrous, but bristly along the margins and densely scabrous on both surfaces. In contrast, the holotype is pubescent on the margins and lower surface of the blades, Adams 3032 is ciliate on the mouth and nearby margins of the sheaths, and Lazarides 7768 is almost entirely glabrous. Also, Adams 3032 is spikelike in its panicle, which resembles the compact spikes of M. compacta and M. subspicata.

Occurs in Kakadu National Park, N.T.; grows on rocky or gravelly, sandstone slopes, platforms, outliers, outcrops and sandy soil flats, often in shallow depressions, and moist, rock sheltered and shady sites, and occasionally on low, lateritic hills. Flowers-fruits February, April.


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