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The grass genera of the world

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

Notodanthonia Zotov

From the Greek notos (south), thus the southern Danthonias.

~ Danthonia sensu lato; Rytidosperma

Type species: Type: N. unarede (Raoul) Zotov.

Excluding Rytidosperma

Habit, vegetative morphology. Perennial; caespitose. The flowering culms leafless. Culms 20–80 cm high; herbaceous; cylindrical; unbranched above; 2–7 noded. Culm nodes exposed; glabrous. Culm internodes solid. Young shoots extravaginal, or intravaginal. Leaves mostly basal; non-auriculate; without auricular setae. Sheath margins free. Leaf blades linear-lanceolate; neither leathery nor flimsy; narrow; 0.3–2 mm wide; flat; not pseudopetiolate; without cross venation; persistent. Ligule present; a fringe of hairs. Contra-ligule absent.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality; hermaphrodite. Not viviparous.

Inflorescence. Inflorescence many spikeleted; paniculate; open; more or less irregular; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes solitary. Spikelets solitary; not secund; pedicellate.

Female-fertile spikelets. Spikelets morphologically ‘conventional’; cuneate; green; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; hairless; the rachilla extension with incomplete florets. Hairy callus present. The callus hairs white. Callus short, or long (more or less equalling the rhachilla); blunt.

Glumes two; relatively large; more or less equal; exceeding the spikelets; long relative to the adjacent lemmas; hairless; scabrous (along veins, especially midrib); pointed; not subulate; awnless; carinate; similar. Lower glume much exceeding the lowest lemma; 3–7 nerved. Upper glume 3–7 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless. Spikelets without proximal incomplete florets.

Female-fertile florets 2–7. Lemmas similar in texture to the glumes; smooth; not becoming indurated; white in fruit; incised; 2 lobed (tapering into slender setae); deeply cleft; awned. Awns 1, or 3; median (if solitary), or median and lateral (if three); from a sinus; geniculate (while the lateral are non-geniculate); hairless; much longer than the body of the lemma; entered by several veins; persistent. Awn bases twisted; flattened. Lemmas hairy. The hairs not in tufts (the upper margin of the indumentum with much longer hairs than on the body, which is generally shortly felted with hairs); not in transverse rows. Lemmas non-carinate; without a germination flap; 9 nerved; with the nerves confluent towards the tip. Palea present; relatively long; not convolute; entire, or apically notched; awnless, without apical setae; thinner than the lemma; not indurated; 2-nerved; 2-keeled. Palea back glabrous, or scabrous, or hairy. Palea keels wingless; scabrous. Lodicules present; 2; free; fleshy; ciliate; not or scarcely vascularized. Stamens 3. Anthers 0.5–1.5 mm long. Ovary apically glabrous. Styles free to their bases; free. Style bases widely separated. Stigmas 2; white.

Fruit, embryo and seedling. Disseminule a caryopsis enclosed in but free of the lemma and palea. Fruit free from both lemma and palea; small; golden-brown; obovate; compressed dorsiventrally; glabrous; smooth. Hilum short (less than 1/3 of caryopsis length). Pericarp thin; fused. Embryo large; waisted.

Transverse section of leaf blade, physiology. C3; XyMS+.

Cytology. Chromosome base number, x = 6. 2n = 24. 2 ploid, or 4 ploid.

Classification. Watson & Dallwitz (1994): Arundinoideae; Danthonieae. Soreng et al. (2015): Danthonioideae; Danthonieae. 5 species.

Distribution, phytogeography, ecology. Australia and New Zealand.

Not commonly adventive. Mesophytic; shade species (light shade); glycophytic.

References, etc. Morphological/taxonomic: Notodanthonia as re-circumscribed by H.P. Linder, who provided this morphological description (1997). Leaf anatomical: studied by us - N. alpicola, N. caespitosa, N. carphoides, N. setacea.

Illustrations. • Lemmas (penicillata, pilosa = Austrodanthonia, semiannularis = Notodanthonia)

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: 11th December 2017.’.