SafePlants

Understanding Leaf Folding in Grasses and Other Plants

This information explores the phenomenon of leaf folding, particularly in grasses, and touches on its broader botanical significance. Leaf folding is a characteristic observed in various plant species and is related to environmental adaptation, species identification, and even artistic applications.

Considerations for Pets

• Some grasses mentioned form dense sod and spread by rhizomes.
• Undigested leaves of grass were found in a study, though this is not necessarily a danger to all species.

Considerations for Children

• Mimosa pudica, also known as the sensitive plant, folds its leaves when touched, making it a popular plant for its curiosity value.

Key Concepts

• Vernation: This term refers to the arrangement of leaves in a bud. It can be rolled, folded, or triangular.
• Leaf Sheath: The part of a grass leaf that encircles the stem.
• Bulliform Cells: Large epidermal cells on the upper surface of grass leaves. Loss of turgor pressure causes leaves to roll or fold.

Leaf Folding: An Adaptive Trait

• Leaf folding or rolling is an adaptive trait studied in various grass species.
• Folded leaves offer reduced exposure to sunlight, decreasing evaporation and conserving water.
• Some grasses have permanently rolled or folded leaves.
• Sapphire buffalo grass's leaf folds at tight angles when mature.

Taxonomic and Morphological Considerations

• Fabaceae: Mimosa pudica belongs to the pea family, Fabaceae.
• Leaves can be greyish to dark green and often folded or rolled.
• Creeping Soft-grass has grey/green leaves.

Identifying Grasses by Leaf Characteristics

• Correct grassweed identification is vital for effective management.
• The shape of an egg, the colour blue, the smell of a leaf?
• Keying out grasses involves observing whether leaves are rolled, folded, or bristle-like.
• Themeda australis is vegetatively similar, but has folded new leaves.

Specific Grass Examples

• Annual meadowgrass: A common grassweed with folded leaves.
• Reed canarygrass (Phalaris arundinacea L.): Some varieties exhibit a folded leaf trait, potentially related to seed retention.
• Common Salt-marsh-grass (Puccinellia maritima): Leaves are often folded or rolled.
• Bermudagrass: Exhibits folded leaf vernation.
• St. Augustinegrass: long leaf blades that remain folded.
• Goosegrass: Has folded leaves in the bud.
• Perennial ryegrass: Has a folded vernation.

Quirky Facts

• Leaves of Grass (First edition 1855 final edition 1892) is a book of poetry by Walt Whitman, which includes the verse: "forth to them folded my love, (dear mariners, for you I fold it here in every leaf)"