Runcinate: Pinnatifid with the lobes pointed and sloping toward the petiole; e.g., the leaves of dandelion (Taraxacum officinale)* Pinnatifid leaves have lobes that are divided halfway or more toward the central …

Hypogeal germination: Seed germination in which the cotyledons remain below the soil surface.* The cotyledons (seed leaves) of peas stay below ground. The first thing to emerge from the soil are …

Epigeal germination: Seed germination in which the cotyledons (seed leaves) are raised above the soil surface.* These arugula seedlings raise their heart-shaped cotyledons above the soil surface to begin photosynthesis before …

Cotyledon: A primary leaf of the embryo; a seed leaf.* This cauliflower seedling has two cotyledons. Cotyledons are not true leaves, they are part of the original embryo inside the seed. …

Signal: (in Irises) A patch of contrasting colour that surrounds or forms a flare on the falls (lower petals) and functions as a signal for pollinating insects.* These irises, blooming …

Ensiform: Lance- or sword-shaped with the widest point toward the base. Synonyms: gladiate, lanceolate.* Ensiform leaves are common in plants in the iris family (Iridaceae), such as the crocus pictured above. …

Pedate: Palmately divided leaf with the lower leaflets further split in two.* The hellebores are beginning to bloom all over the garden this week. Many hellebores have pedate leaves. *Pell, S.K., Angell, …

Spine: Sharp, pointed modified leaf, leaflet, bract, sepal, or stipule.* These Berberis (barberry) spines are actually modified leaves. Botanically, they’re different from thorns or prickles which are derived from other plant …