Also called the leaf stalk, the petiole is actually an expansion of the leaf in plants. It’s the structure which connects the leaf to the stem or trunk of vascular plants. The petiole is an integral player in plant work.
In vascular plants, phloem and xylem cells are organized in bundles, which form transportation systems which channel nutrients and water to nourish plants. The petiole serves as a bridge which permits carbohydrates, which are manufactured in the leaves, to move through a plant, and the petiole allows water and dissolved minerals, which can be consumed by the roots, to move into the leaves. In plants, the petiole is able to seal off the motion of water and carbohydrates in fall, and the leaves drop.
Petioles are numerous lengths, and lack petioles are left by some entirely. They’re called sessile or stalkless leaves — like the leaves of wood lily (Trillium sessile), which can be hardy in U.S. Department of Agriculture plant hardiness zones 4 through 8. Some petioles are very long, fleshy and edible, such as those of and rhubarb (Rheum x hybridum), a herbaceous perennial in USDA zones 3 through 8.
Unfortunately, the identical petiole pathway which eases water and nutrient transport may allow pests to feed on the carbohydrates within the petiole. Sawflies, that can be non-stinging wasps, feed on plant cells, burrow through the petiole and put eggs near the base of a petiole; larvae hatch out of the eggs. The maple petiole borer (Caulocampus acericaulis) feeds indoors petioles till they split, which causes those petioles’ leaves to collapse. All maple species (Acer spp.) Are vulnerable to petiole borer attacks, but some are especially susceptible, such as sugar maple (Acer saccharum), hardy in USDA zones 3 through 8, and red maple (Acer rubrum), hardy in USDA zones 3 through 9.
Petioles are a propagator’s fantasy for some plants, such as African violet (Saintpaulia Ionantha), a perennial in USDA zones 11 through 12, and peperomia (Peperomia obtusifolia), a perennial in USDA zones 10 through 11. If you add the petiole into a moist and remove a leaf , soilless medium, like peat moss a plant — or numerous plants — will type in the base of the petiole. After you remove each new plant and pot it individually, you may use if enough of this petiole stays the leaf cutting to propagate another plant.