| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### Austroderia N.P. Barker & H.P. Linder

~ Cortaderia

Habit, vegetative morphology. Perennial; tough, caespitose (usually), or caespitose. Culms 50–600 cm high. Leaf blades broad (with several wide, strongly sclerified veins as well as smaller indistinctly sclerified ones); not pseudopetiolate; shiny, white, persistent. Ligule present; a fringe of hairs (sometimes with several rowed).

Reproductive organization. Plants bisexual, all with bisexual spikelets, or dioecious (gynodioecious); with hermaphrodite florets, or without hermaphrodite florets. The spikelets hermaphrodite, or female-only.

Inflorescence. Inflorescence paniculate; open to contracted (plumose); espatheate. Spikelets pedicellate.

Female-sterile spikelets. The male spikelets less hairy than the female-fertile ones. The male spikelets similar to the others, with glumes; 2–7 floreted (?). The lemmas awnless. Male florets 2–5 (?); 3 staminate.

Female-fertile spikelets. Spikelets 10–50 mm long; cuneate; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla probably prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus present (villous). Callus blunt (shorter than the internode).

Glumes present; two; more or less equal; about equalling the spikelets to exceeding the spikelets; long relative to the adjacent lemmas; hairless; glabrous, or scabrous (or finely scaberulose); pointed; awnless (setaceously attenuate); carinate; linear, hyaline, similar. Lower glume much exceeding the lowest lemma; 1 nerved. Upper glume 1 nerved. Spikelets with incomplete florets (probably), or with female-fertile florets only (ambiguous descriptions ...). The incomplete florets if present, distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awned.

Female-fertile florets (2–)3–7 (?). Lemmas similar in texture to the glumes; not becoming indurated; slightly entire, or incised; pointed (attenuate); if incised, 2 lobed (sometimes with long setae); not deeply cleft; awned. Awns 1; median; from a sinus, or apical; non-geniculate; straight, or flexuous (?); much shorter than the body of the lemma to much longer than the body of the lemma (?). Awn bases not twisted. Lemmas hairy (dorsally pilose). The hairs not in tufts; not in transverse rows. Lemmas non-carinate; 3 nerved. Palea present; not indurated; 2-nerved; occasionally hair-tufted on the margins. Palea keels ciliolate or not. Lodicules present; 2; rhomboid to fleshy; ciliate, or glabrous (usually with microhairs and bristles). Stamens 3, or 0. Ovary apically glabrous.

Fruit, embryo and seedling. Disseminule a free caryopsis. Fruit free from both lemma and palea; lorate, elliptical, turbinate or obovate; not grooved. Hilum long-linear (about half the fruit length). Pericarp fused. Embryo large (about half the length of the caryopsis).

Transverse section of leaf blade, physiology. Presumably C3.

Cytology. 2n = 90.

Classification. Watson & Dallwitz (1994): genus not recognised. Soreng et al. (2015): Danthonioideae; Danthonieae. 5 species.

Distribution, phytogeography, ecology. Australia and New Zealand.

Australian and Antarctic.

References, etc. Morphological/taxonomic: N.P. Barker & H.P. Linder, (2010) Ann. Missouri Bot. Gard. 97: 343 (2010); Grassbase (2016); E.A. Kellogg (2015) in Kubitzki XIII.

Special comments. Sexuality of the plants is described and qualified using the same ambiguous wording in all the descriptions seen; viz., "gynodioecious ("male", in this context, indicating the bisexual state", = ?). Anatomical data wanting.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 15th June 2025. delta-intkey.com’.

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