Electronic Flora of South Australia
Electronic Flora of South Australia
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Electronic Flora of South Australia genus Fact Sheet

Family: Poaceae

Citation: Nees, London J. Bot. 2:420 (1843).

Derivation: Greek amphi, about; Bromus, a grass genus; near the genus Bromus.

Synonymy: Not Applicable

Common name: Swamp wallaby-grasses.

Slender caespitose or stoloniferous perennials to 1.5 m tall; leaf blades linear, narrow, flat or inrolled; ligule membranous, elongated.

Inflorescence a narrow loose elongated panicle; branches slender, erect or flexuose; spikelets pedicellate, solitary, rhachilla disarticulating above the glumes and between the lemmas; florets 3-10, bisexual, 7-20 mm long (excluding the awns); glumes 2, obtuse or acute, more or less keeled; lemmas longer than the glumes, firm, 2-4-toothed or -lobed with the lobes aristate or obtuse, 5-7-nerved, with an awn arising from about the middle to just below the apex, the awn twisted or scarcely so, geniculate or scarcely so, recurved or scarcely so; callus prominent, hairy.

Grain glabrous.

Distribution:  Generally semi-aquatic plants of wet or periodically inundated habits. About 12 species; 10 in Australia (9 endemic), 1 in New Zealand and 2 in South America.

Biology: Cleistogamy (fertilisation in unopened florets) is fairly common, with cleistogamous florets intermixed with chasmogamous (opening florets) florets in the same spikelet or cleistogamous spikelets may remain in reduced inflorescences enclosed in the leaf sheaths.

Key to Species:
1. Lemma apex toothed, with the nerves of the teeth extended as bristles; inner teeth and bristles more than 2.5 mm long
A. archeri 1.
1. Lemma apex toothed, but nerves not extended as bristles
2. Lemma densely hispid, 4-5.2 mm long, with 4 teeth of more or less equal length; awn scarcely twisted
A. recurvatus 4.
2. Lemma scabrous or papillose, not hispid, 5-8 mm long; teeth 2-4, if 4 the outer generally shorter or poorly developed; awn twisted
3. Lemma with a drawn-out chartaceous apex, back very roughly papillose, awn arising 50-60% of the lemma length from the apex
A. macrorhinus 2.
3. Lemma apex evenly tapering from the body of the lemma, back smooth to scabrous, awn arising 40-55% of the lemma length from the apex
A. nervosus 3.

Author: Prepared by L. Lapinpuro

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