The grass genera of the world
Including L. phleoides (Vill.) Reichenb., Koeleria phleoides (Vill.) Pers., Rostraria cristata (L.) Tsvelev, Trisetaria phleoides (Vill.) Nevski
Habit, vegetative morphology. Annual; caespitose. Culms 5–60 cm high; herbaceous; unbranched above. Culm nodes glabrous. Young shoots intravaginal. Leaves not basally aggregated; non-auriculate. Sheaths hairy. Leaf blades linear; apically cucullate, or apically flat; narrow; 1.2–8 mm wide; flat; without cross venation; persistent; rolled in bud. Ligule an unfringed membrane (ciliolate); not truncate. Contra-ligule absent.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence paniculate; contracted; more or less ovoid to spicate (in specimens seen), or more or less irregular. Primary inflorescence branches borne distichously. Inflorescence espatheate; not comprising partial inflorescences and foliar organs. Spikelets not secund; pedicellate; imbricate.
Female-fertile spikelets. Spikelets 3–7.5 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with distinctly elongated rachilla internodes between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; shortly hairy; the rachilla extension with incomplete florets. Hairy callus present. Callus short.
Glumes two; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; hairy (on their keels); pointed; awnless; carinate; similar (glabrous, apart from the ciliate keel, the lower smaller and narrower). Lower glume 0.6–0.75 times the length of the upper glume; considerably shorter than the lowest lemma; 1 nerved. Upper glume 3 nerved. Spikelets with female-fertile florets only (if the terminal floret, which is well developed in some of the material seen, is ever complete), or with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped; awnless.
Female-fertile florets 3–6 (in material seen). Lemmas complanate; similar in texture to the glumes (thinly membranous); not becoming indurated; incised; briefly 2 lobed; not deeply cleft; awned. Awns 1; median; dorsal; from near the top; non-geniculate (and not twisted); hairless (scabrous); much shorter than the body of the lemma; entered by one vein. Awn bases not twisted. Lemmas hairy to hairless (the lowest lemma pubescent on the back, the others scabrous); carinate; without a germination flap; 5 nerved; with the nerves non-confluent. Palea present; conspicuous but relatively short (about two thirds to three quarters of the lemma length); gaping; apically notched; with apical setae (by short continuation of the keel nerves); thinner than the lemma (hyaline); not indurated; 2-nerved; 2-keeled. Palea keels wingless; scabrous. Lodicules present; 2; free; membranous; glabrous; not or scarcely vascularized. Stamens 3. Anthers 0.2–0.5 mm long (oblong); not penicillate; without an apically prolonged connective. Ovary apically glabrous. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit small. Hilum short. Embryo small. Endosperm liquid in the mature fruit.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally to markedly different in shape costally and intercostally (the costals mostly narrower); of similar wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata common (but mostly bordering the costae). Subsidiaries parallel-sided. Guard-cells overlapped by the interstomatals. Intercostal short-cells absent or very rare. Costal zones with short-cells. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies poorly developed (and scarce, in the material seen); horizontally-elongated crenate/sinuous to horizontally-elongated smooth (mostly ill defined, in the material seen); not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs to nodular in section; with the ribs more or less constant in size (round topped). Midrib not readily distinguishable; with one bundle only. The lamina symmetrical on either side of the midrib. Bulliforms not present in discrete, regular adaxial groups (or with a slight tendency to simple fans in the furrows). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the major bundles, the minor bundles with strands only); forming figures (sometimes with ill-defined Is), or nowhere forming figures.
Cytology. Chromosome base number, x = 7. 2n = 14, 21, and 28. 2, 3, and 4 ploid. Chromosomes large.
Classification. Watson & Dallwitz (1994): Pooideae; Poodae; Aveneae. Soreng et al. (2015): cf. Pooideae (? - as a synonym); Poodae; Poeae; Aveninae.
Distribution, phytogeography, ecology. Mediterranean and southwest Europe to western France and eastern Bulgaria.
Commonly adventive. Mesophytic to xerophytic. Cultivated ground and dry sandy grassland.
References, etc. Leaf anatomical: this project.
Illustrations. • L. cristata: Gardner, 1952. • Inflorescence. • Spikelets
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: 13th November 2017. delta-intkey.com/grass’.