''Decurrent'' (sometimes decurring) is a term used in

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

and

mycology Mycology is the branch of biology concerned with the study of fungus, fungi, including their Taxonomy (biology), taxonomy, genetics, biochemistry, biochemical properties, and ethnomycology, use by humans. Fungi can be a source of tinder, Edible ...

to describe plant or fungal parts that extend downward. In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petiole and extend down along the stem. A "decurrent branching habit" is a plant form common for

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s and most

angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit ...

trees, contrasted with the excurrent or "cone-shaped crown" common among many

gymnosperm The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...

s. The decurrent habit is characterized by having weak

apical dominance In botany, apical dominance is the phenomenon whereby the main, central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; on a branch the main stem of the branch is further dominant over its own side twigs. P ...

that eventually produces a rounded or spreading tree crown. Examples of trees with decurrent habit are most

hardwood Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostl ...

trees:

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

hickory Hickory is a common name for trees composing the genus ''Carya'', which includes 19 species accepted by ''Plants of the World Online''. Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve ...

maple ''Acer'' is a genus of trees and shrubs commonly known as maples. The genus is placed in the soapberry family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated si ...

, etc.Claud L. Brown, Robert G. McAlpine, Paul P. Kormanik, "Apical Dominance and Form in Woody Plants: A Reappraisal", ''American Journal of Botany'', Vol. 54, No. 2 (February 1967), pp. 153–162, In mycology, the term is most often applied to the

hymenophore A hymenophore refers to the hymenium-bearing structure of a fungal fruiting body. Hymenophores can be smooth surfaces, lamellae, folds, tubes, or teeth. The term was coined by Robert Hooke Robert Hooke (; 18 July 16353 March 1703) was an ...

of a

basidiocarp In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

(such as the

lamellae Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...

or "gills" of a mushroom or the "pores" of a bracket fungus) when it is broadly attached to and extends down the stipe.

References

{{Reflist, refs= {{cite book , author=Ammirati J, Trudell S. , title=Mushrooms of the Pacific Northwest: Timber Press Field Guide (Timber Press Field Guides) , publisher=

Timber Press Workman Publishing Company, Inc., is an American Publishing companies, publisher of Tradebook, trade books founded by Peter Workman. The company consists of Imprint (trade name), imprints Workman, Workman Children's, Workman Calendars, Artisan ...

, location=Portland, Oregon , year=2009 , page=316 , isbn=978-0-88192-935-5 Claud L. Brown, Robert G. McAlpine, Paul P. Kormanik, "Apical Dominance and Form in Woody Plants: A Reappraisal", ''American Journal of Botany'', Vol. 54, No. 2 (February 1967), pp. 153–162, {{doi, 10.2307/2440793 {{cite journal , last=Harris RW. , title=Structural Development of Trees , journal=Journal of Arboriculture , volume=6 , issue=4 , pages=105–107 , publisher=International Society of Arboriculture , date=April 1980 Plant morphology Fungal morphology and anatomy