Grass Genera of the World

L. Watson and M. J. Dallwitz


Koeleria Pers.

Named for early German agrostologist, G.L.Koeler.

Including Aegialina Schult., Aegialitis Trin., Airochloa Link, Brachystylus Dulac, Ktenosachne Steud., Leptophyllochloa Cald., Lophochloa Reichenb., Poarion Reichenb., Rostraria Trin., Wilhelmsia Koch

Excluding Avellinia

Habit, vegetative morphology. Annual (Lophochloa, Rostraria), or perennial; caespitose (usually), or rhizomatous (rarely). Culms 5–120 cm high; herbaceous; tuberous, or not tuberous. Culm nodes glabrous. Culm internodes hollow. Leaves non-auriculate; without auricular setae. Sheath margins free. Leaf blades linear; narrow; 0.5–6 mm wide; flat, or folded, or rolled (convolute); without cross venation; persistent; ligule present; an unfringed membrane (sometimes puberulent and ciliolate); truncate, or not truncate.

Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets; outbreeding and inbreeding.

Inflorescence. Inflorescence paniculate; contracted (not interrupted); more or less ovoid, or spicate; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.

Female-fertile spikelets. Spikelets (2.7–)4–7 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairy, or hairless. Hairy callus present, or absent. Callus short.

Glumes two; very unequal, or more or less equal; shorter than the spikelets, or about equalling the spikelets; shorter than the adjacent lemmas (rarely), or long relative to the adjacent lemmas (the G2 usually equalling the first lemma); pointed; awnless; carinate; very dissimilar (sometimes, e.g. K. pumila), or similar. Lower glume 1–3 nerved. Upper glume 3 nerved, or 5 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets distal to the female-fertile florets. Spikelets without proximal incomplete florets.

Female-fertile florets 2–4. Lemmas similar in texture to the glumes; not becoming indurated; entire (usually), or incised (e.g. in Lophochloa); blunt; awnless, or mucronate, or awned (but then the awns relatively inconspicuous, by contrast with Trisetum). Awns 1; median; from a sinus, or dorsal; from near the top; non-geniculate; much shorter than the body of the lemma to about as long as the body of the lemma; entered by one vein. Lemmas hairy, or hairless; carinate; 3–5 nerved. Palea present; relatively long (usually), or conspicuous but relatively short (e.g. K. cristata, K. pumila); gaping; apically notched; thinner than the lemma (hyaline or membranous); not indurated; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; glabrous; toothed. Stamens 3. Anthers 0.3–0.7 mm long (Rostraria), or 1.3–3 mm long; not penicillate. Ovary glabrous; without a conspicuous apical appendage. Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit small; slightly compressed laterally. Hilum short, or long-linear. Embryo small; not waisted. Endosperm liquid in the mature fruit; with 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, or with a long 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 similar in shape costally and intercostally, or markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally (thin walled). Intercostal zones with typical long-cells, or exhibiting many atypical long-cells. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata absent or very rare, or common. Subsidiaries low dome-shaped, or parallel-sided. Guard-cells overlapped by the interstomatals. Intercostal short-cells absent or very rare; in cork/silica-cell pairs, or not paired (some solitaries, and abundant prickles); silicified (when paired), or not silicified. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous to horizontally-elongated smooth, or rounded, or saddle shaped (occasionally).

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Leaf blade with distinct, prominent adaxial ribs, or ‘nodular’ in section; with the ribs more or less constant in size. Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups (between the vascular bundles), or not present in discrete, regular adaxial groups (e.g. K. cristata, K. pumila); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.

Phytochemistry. Leaves without flavonoid sulphates (1 species).

Special diagnostic feature. Panicle dense, cylindrical, ovoid, not interrupted: awns if present straight, subterminal, inconspicuous in the inflorescence.

Cytology. Chromosome base number, x = 7. 2n = 14, 26, 28, 40, 42, 43, 56, 70, 84, 112, and 126. 2, 4, 6, 8, 10, 12, 16, and 18 ploid (and aneuploids). Chromosomes ‘large’.

Taxonomy. Pooideae; Poodae; Aveneae.

Distribution, ecology, phytogeography. About 60 species; north and south temperate. Commonly adventive. Mesophytic, or xerophytic; mostly species of open habitats. In dry grassland and rocky places.

Holarctic, Paleotropical, Neotropical, Cape, and Antarctic. Boreal, Tethyan, and Madrean. African. Arctic and Subarctic, Euro-Siberian, Eastern Asian, and Atlantic North American. Mediterranean and Irano-Turanian. Sudano-Angolan and West African Rainforest. Pampas, Andean, and Fernandezian. New Zealand and Patagonian. European and Siberian. Canadian-Appalachian and Southern Atlantic North American. Sahelo-Sudanian, Somalo-Ethiopian, and South Tropical African.

Hybrids. Intergeneric hybrids with Trisetum: ×Trisetokoeleria Tsvelev.

Rusts and smuts. Rusts — Puccinia. Taxonomically wide-ranging species: Puccinia graminis, Puccinia coronata, Puccinia striiformis, Puccinia poarum, Puccinia hordei, Puccinia recondita, and Puccinia monoica. Smuts from Tilletiaceae and from Ustilaginaceae. Tilletiaceae — Entyloma, Tilletia, and Urocystis. Ustilaginaceae — Ustilago.

Economic importance. Significant weed species: K. phleoides, K. pyramidata. Important native pasture species: e.g. K. cristata.

References, etc. Leaf anatomical: Metcalfe 1960 and this project.

Special comments. The taxonomic situation around Koeleria and Trisetum (involving Trisetaria, Graphephorum, Rostraria, Lophochloa and Peyritschia) is hopelessly unsatisfactory, and demands either a world monograph of the approximately 150 species involved, or critical assessment via extensive worldwide sampling and an adequate character list. This sensu lato version of Koeleria reflects the impossibility of preparing adequate descriptions for segregate genera, and is poorly separable from that of Trisetum.

Illustrations. • General aspect. • Spikelet. • General morphology. • Inflorescence. • Spikelets. • General aspect. • Inflorescence. • Spikelets


Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘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.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).

Index