This Australian tree fern is producing a new frond by the process of circinate vernation

Vernation (from vernal, since that is when leaves "spring forth" in Temperate regions) is the formation of new leaves or fronds. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. A frond is a large Leaf with many divisions to it and the term is typically used for the leaves of palms Ferns or Cycads A frond is In plant anatomy, it is the arrangement of leaves in a bud.

In pine trees, new leaves are short and encased in sheaths. This article is about the tree For other uses of the term "pine" see Pine (disambiguation. Each leaf bundle consists of 2 to 5 needles. All the leaves on one section of branch grow in length together. In the cabbage, new leaves are folded over, each covered by the previous leaf. The cabbage ( Brassica oleracea var capitata) is a leafy garden plant of the Family Brassicaceae (or Cruciferae used as a

Circinate vernation

Circinate vernation is the name given to the manner in which new fern fronds emerge. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta As a new fern frond is formed, it is tightly curled so that the tender growing tip of the frond (and each subdivision of the frond) is protected within a coil. At this stage it is called a crozier (after the shepherd's crook) or fiddlehead (after the scrollwork at the top of a violin). Fiddlehead ferns refers to the unfurled fronds of a young Fern harvested for food consumption As the lower parts of the frond expand and toughen up, they begin to photosynthesize, supporting the further growth and expansion of the frond. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. In the case of many fronds, such as that of the Australian tree fern in the picture at right, long hairs or scales provide additional protection to the growing tips before they are fully uncoiled.

Circinate vernation may also be observed in the extension of pinnae, or leaflets, in the compound leaves of the Cycads (Division Cycadophyta). A leaflet in Botany is a part of a compound Leaf. A leaflet may resemble an entire leaf but it is not borne on a stem as a leaf is but rather Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk.