• keymus arenaria,
• peymus arenaria,
• oeymus arenaria,
• lwymus arenaria,
• lsymus arenaria,
• ldymus arenaria,
• lrymus arenaria,
• l4ymus arenaria,
• l3ymus arenaria,
• letmus arenaria,
• legmus arenaria,
• lehmus arenaria,
• leumus arenaria,
• le7mus arenaria,
• le6mus arenaria,
• leynus arenaria,
• leykus arenaria,
• leyjus arenaria,
• leymys arenaria,
• leymhs arenaria

The adjective form of the phrase "leymus arenaria" is "leymus arenaria". The phrase itself refers to a specific type of grass, commonly known as beachgrass or marram grass. In this case, "leymus arenaria" is used as a proper noun to indicate the specific species. Adjectives would typically be used to describe characteristics of the grass, such as "tall," "sturdy," or "coastal".

The plural form of "Leymus Arenaria" is "Leymus Arenaria" as it is a scientific name and is not typically pluralized.

The singular form of the word "Leymus Arenaria" is "Leymus Arenarius".