Lolium multiflorum Lam.
Lolium italicum A. Braun, L. perenne L. subsp. multiflorum (Lam.) Husnot
|Author: Alain Peeters|
Italian ryegrass (English), Ray-grass d'Italie (French), Italienisches Raigras (German).
There are 2 types of Italian ryegrass: the westerwoldicum type, the Westerwold ryegrass that is annual. The plants die after seed formation. And the multiflorum or italicum type, the typical Italian ryegrass that is a short living perennial. It persists usually 2 to 3 years.
Annual or perennial plant, very robust, rather big, hairless, cespitous. Stems erect, 20 - 100 cm high. Blade rolled when young, large (up to 10 mm), long (6 - 25 cm), flexible, pale green, shiny on the lower side, less than 16 well marked veins on the upper side (more than 16 veins in Festuca pratensis). Sheaths of the lower leaves purple-red. Ligule quite short, membranous. Auricles long, well developped. Spike-like inflorescence. Spikelets 10 - 14 flowered (up to 20 - 25) applied on the axis by one of their sides. One glume per spikelet except on the top spikelet where there are 2. Glume shorter than the spikelet. Lemma exceeds the glume and is usually aristate (see L perenne). The weight of 1000 seeds is Multiflorum diploid varieties: 2.0 to 2.5 g (average seeds), tetraploid varieties: 3.0 to 4.6 g (average to big seeds), Westerwold diploid varieties: 2.5 to 3.0 g (average seeds), tetraploid varieties: 3.7 to 5.1 g (big seeds). Chromosome number: 2n = 14 (diploid), 2n = 28 (tetraploid). Physiological peculiarities: Hybridizes with Lolium perenne: L. x hybridum Hausskn. Hybridizes very rarely with Festuca pratensis and F. arundinacea: x Festulolium. This opportunity of hybridization is used in artificial breeding to get hybrids more resistant to drought and more persistant.
Requires mild or warm climates. Very sensitive to winter cold. Tolerates heat providing that the water supply is sufficient. Can be cultivated in rather cold climates but its persistance is then reduced.
Sensitive to summer drought.
Optimum on normally drained soils. Dry or very wet soils are not suitable. Very sensitive to winter flooding. Needs nutrient rich soils, slightly acid to alkaline. Small requirements for soil texture.
Native to Central and Southern Europe, to North Africa and to SW Asia. Introduced in most temperate regions. From the lowlands to about 800 m in the Alps.