| # The grass genera of the world |

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

### Nardus L.

Indirectly from the Greek nardos, the classical name for Spikenard (Valerianaceae). This came to be applied to other aromatic plants including grasses (e.g. Cymbopogon nardus), then by other associations to non-aromatic grasses, and finally by Linnaeus to several grasses with spicate inflorescences (see Bor 1968).

Type species: Type: N. stricta L.

Including Natschia Bub.

Habit, vegetative morphology. Tough, wiry perennial; caespitose. Culms 10–50 cm high; herbaceous. Culm nodes glabrous. Culm internodes hollow. Young shoots extravaginal. Leaves mostly basal; non-auriculate. Smooth. Leaf blades linear (sharp pointed); narrow (about 0.5 mm in diameter, 4–30 cm long); setaceous; tightly rolled; without cross venation; persistent; rolled in bud. Ligule an unfringed membrane; not truncate (blunt); 2 mm long.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. Apomictic (non-pseudogamous), or reproducing sexually.

Inflorescence. Inflorescence a single spike (slender, one-sided). Inflorescence axes not ending in spikelets (terminating in a bristle up to 1 cm long). Rachides hollowed. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund; biseriate; sessile; loosely to closely imbricate.

Female-fertile spikelets. Spikelets 5–9 mm long (narrow); (the larger) more or less abaxial; compressed laterally; disarticulating above the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent. Callus short; blunt.

Glumes one per spikelet, or two; minute; very unequal; shorter than the adjacent lemmas (G1 a small scale, G2 minute or absent); joined (their rudiments joined with one another and with the rachis); hairless; awnless. Lower glume 0 nerved. Upper glume 0 nerved. Spikelets with female-fertile florets only.

Female-fertile florets 1. Lemmas linear-lanceolate or lanceolate-oblong; decidedly firmer than the glumes; not becoming indurated (papery); entire; pointed; awned. Awns 1; median; apical; non-geniculate; hairless; much shorter than the body of the lemma (1–3 mm long). Lemmas hairless; non-carinate (2–3 keeled); 3 nerved. Palea present; relatively long; entire; awnless, without apical setae; thinner than the lemma; 2-nerved. Lodicules absent. Stamens 3. Anthers 2.5–4 mm long; not penicillate. Ovary apically glabrous. Styles fused (assuming the ostensibly single style represents fusion of two). Stigmas 1.

Fruit, embryo and seedling. Fruit small. Hilum short (but linear). Embryo small; not waisted. Endosperm hard; without lipid; containing compound starch grains. Embryo with an epiblast; without a scutellar tail; with a negligible mesocotyl internode. Embryonic leaf margins meeting.

Seedling with a short mesocotyl; with a tight coleoptile. First seedling leaf with a well-developed lamina. The lamina narrow; erect; 3 veined.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; (68–)72–96(–105) microns long; 6.6–10.5 microns wide at the septum. Microhair total length/width at septum 9–15.6. Microhair apical cells (34–)42–52(–54) microns long. Microhair apical cell/total length ratio 0.45–0.61. Stomata absent or very rare, or common; when present, 25.5–30–33 microns long. Subsidiaries triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; in cork/silica-cell pairs (and solitary); silicified. Intercostal silica bodies tall-and-narrow and cubical. With abundant intercostal macrohairs. Costal short-cells neither distinctly grouped into long rows nor predominantly paired (mostly 1–5, but in a few places the intervening ‘long-cells’ are short). Costal silica bodies rounded, saddle shaped, and tall-and-narrow (intergrading, sometimes almost cubical); not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size. Midrib conspicuous; with one bundle only. Bulliforms not present in discrete, regular adaxial groups (small, variable in size, in the bases of the furrows). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.

Cytology. Chromosome base number, x = 13. 2n = 26–30 (the chromosomes ‘fairly large’). 2 ploid.

Classification. Watson & Dallwitz (1994): Stipoideae; Nardeae. Soreng et al. (2015): Pooideae; Nardeae. 1 species (N. stricta).

Distribution, phytogeography, ecology. Europe, western Asia.

Commonly adventive. Xerophytic; species of open habitats; glycophytic. Moorland.

Economic aspects. Very unpalatable to stock.

References, etc. Leaf anatomical: Metcalfe 1960, and studied by us.

Special comments. An isolated genus of uncertain taxonomic affinities, despite excellent descriptive data. Primitive numerical taxonomic analyses of Metcalfe’s leaf blade anatomical descriptions conducted in 1963 (Watson, unpublished) presented Nardus with Lygeum as an ‘outlying’ group, and this has been a consistent feature of most analyses performed subsequently in course of developing this data set. They seem closest to Stipeae, but are prime candidates for comparative DNA studies.

Illustrations. • General aspect (Nardus stricta): J. Curtis, 1824. • Nardus stricta, general aspect: Eng. Bot. 1872). • Nardus stricta, abaxial epidermis of leaf blade: this project.

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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