Leymus arenarius

Leymus arenarius
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
(unranked):	Commelinids
Order:	Poales
Family:	Poaceae
Genus:	Leymus
Species:	L. arenarius
Binomial name
Leymus arenarius (L.) Hochst.

Leymus arenarius (L.) Hochst. (syn. Elymus arenarius L.) is a psammophilic (sand-loving) species of grass in the family Poaceae, native to the coasts of Atlantic and Northern Europe. Leymus arenarius is commonly known as sand ryegrass,sea lyme grass, or simply lyme grass.

Leymus arenarius originated from the hybridization of L. racemosus and another unknown species in central Eurasia or from a polyploidization event. DNA analysis shows that inland and coastal plants are statistically not different from each other. L. arenarius is a recent cultivar, and has had little time to accumulate genetic differences.Leymus arenarius is much younger than its North American relative L. mollis, which has been around since the ice age. Icelandic L. arenarius is molecularly uniform. Polish L. arenarius is also reported to be molecularly uniform.

Leymus arenarius is native to the coasts of northern and western Europe. A closely related species Leymus mollis (previously Elymus arenarius ssp. mollis)is native to the northern coasts of North America.

Leymus arenarius can grow exponentially in terms of height and root growth in the presence of nitrogen. Leymus arenarius is known to take up nitrogen into its root system. Raising nitrogen concentrations can aid in growth as over time plant mass above to surface will not change, but will accumulate in the root system. The roots themselves also retain nitrogen as they come in contact with it and in the surrounding un-vegetated areas. This assists in primary succession with surrounding flora and fauna, and a decrease in soil erosion. After volcanic events L. arenarius causes dunes and their soil depth to grow exponentially over time. Nitrogen increases seed production, raising the yield of seeds as much as 70% in Icelandic L. arenarius. The seed density also increased with the addition of nitrogen, in comparison to phosphorus and potassium which only produce marginal increases for both seed yield and density. Leaf size and density are also influenced by nutrient additions. Removing nitrogen, phosphorus, or potassium resulted in a reduction of leaf mass up to 20%. Nitrogen usage is a cost effective tool to use to increase abundance and effectiveness of L.arenarius.

Leymus arenarius benefits from the presence of arbuscular mycorrhizal fungi. The presence of the fungi increases the ability of L. arenarius to have an extensive root system and to bind soil particles. When adding fungi in its natural habitat, more seeds survived and grew than without the fungi present.

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Wikipedia