Amphibromus macrorhinus S.W.L.Jacobs & Lapinpuro, Telopea 2: 723 (1986).

T: On the Wangaratta road, 6 mi (10 km) from Whitfield, Vic., 1 Nov. 1960, T.B.Muir 1682; holo: NSW, iso: MEL, AD

Illustrated in: Fl. N.S.W. 4: 597 (spikelet and floret).

Vegetative form. Perennial, caespitose. Culms to 100 cm high, 2-4 noded. Mid-culm nodes glabrous, exposed, constricted. Mid-culm internodes hollow, glabrous or scabrous (slightly), terete or compressed (slightly). Leaves non-auriculate. Basal leaf sheaths not keeled, terete, glabrous or scabrous (at the base, the hairs sparse), with the veins equally striate. Ligule 6-17 mm long, membranous, acute, entire (becoming lacerated with age). Leaf blades flat or involute, linear, to 300 mm long, 1.5-4 mm wide; adaxially hirsute (the hairs short and spreading on the veins), channelled; abaxially scabrous, with the veins equally striate.

Reproductive organization. Plants bisexual. Incomplete spikelets absent. Inflorescence of cleistogamous spikelets, or chasmogamous spikelets (with cleistogamous and/or chasmogamous florets).

Inflorescence. Inflorescence a panicle, erect, open or contracted, symmetrical. Rachides to 400 mm long, terete (becoming angled toward the apex), glabrous (becoming scabrous toward the apex). Primary inflorescence branches glabrous or scabrous; solitary or clustered, spreading or appressed (to 8 cm long). Spikelets erect, spreading.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 10-17 mm long, laterally compressed, not disarticulating as a separate unit, disarticulating above the glumes. Pedicels to 20 mm long, erect, scabrous, straight. Glumes two per spikelet, dissimilar (the upper longer and broader), subequal to unequal in length (pale green), shorter than the florets, approximately half the proximal lemma in length (?). Lower glume c. 2/3s the length of the upper glume (?), narrowly ovate, 3.9-7 mm long, 1.3-1.6 mm wide, weakly keeled, acuminate to acute, muticous, margin hyaline; 3-4 veined (1-3 in Morris !); intercostal regions glabrous. Upper glume ovate, 4.2-7.5 mm long, 1.5-2.6 mm wide, weakly keeled, acute, muticous, margin hyaline; 5 veined, midvein glabrous or midvein papillose; intercostal regions glabrous. Rudimentary florets distal to the hermaphrodite florets (?). Incomplete florets absent (?). Hermaphrodite florets 4-5 per spikelet (cleistogamous and/or chasmogamous). Rachilla disarticulating between the florets, disarticulating directly below the florets, segments bearded at the apex, apically prolonged; terminated by a rudimentary floret (?). Callus present, blunt, hirsute (?). Lemma laterally compressed, 5.3-8 mm long, chartaceous (?), not keeled, dentate (the inner teeth 0.5-1.15 mm long, the outer teeth shorter), 4 -lobed; apex hyaline; awned. Lemma 7 veined. Lemma veins not confluent apically (and not extending to the margin), papillose, with the hairs on all the veins, with the hairs extending the length of the veins (except the apex); intercostal regions papillose, the hairs over the entire dorsal surface (except the apex). Awns 1, median. Median awn about as long as the body of the lemmas or much longer than the body of the lemmas, 10-19 mm long, 1 veined, dorsal, arising from the mid-point of the lemma (or just below), geniculate, column twisted, scabrous (pale green to darker brown). Palea fully developed, 2/3s the length of the lemma to slightly shorter than the lemmas (65-95% of the lemma length), 2-keeled, keels wingless, acute; 2 veined, veins ciliate (hairs dense); intercostal regions papillose. Lodicules 2, free, hyaline, acute, glabrous. Stamens 3. Anthers 2.7-3 mm long. Cleistogamous anthers 0.5-0.8 mm long.

Fruit. Fruit free from both lemma and palea, oblong, dorsiventrally compressed (dorsally), 1.5-2.25 mm long, glabrous (yellow-brown). Hilum 30-40% of the length of the caryopsis, linear (red-brown). Embryo 15-20% of the length of the caryopsis.

Distribution. Endemic. Tasmania, New South Wales, Victoria, Western Australia, and South Australia.

Ecology. Grows on floodplains and banks of inland and coastal rivers of southern Australia. Flowers in response to rain or flooding.

Vouchers. Specimens examined morphologically: Tas.: Epping Forest, Midlands Hwy, 16 Dec. 1968, W.M.Curtis (HO).

Classification. Pooideae; Poodae; Aveneae.

Similar to A. nervosus but distinguished by the awn which is inserted lower down, and the more drawn-out and chartaceous lemma apex.

References. Morphology: Jacobs & Lapinpuro 723-724 (1986); Morris 59 (1991). Taxonomy: Jacobs & Lapinpuro 723 (1986).

Cite this publication as:
C.M. Weiller, M.J. Henwood, J. Lenz and L. Watson (1995 onwards). `Pooideae (Poaceae) in Australia - Descriptions and Illustrations'. URL http://muse.bio.cornell.edu/delta/
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.

References and Acknowledgements