Editing Birch (section)

==Description==
{{More citations|section|date=March 2023}}
[[File:Birch bark front rear.jpg|left|thumb|upright|The front and rear view of a piece of birch [[Bark (botany)|bark]]]]

Birch species are generally small to medium-sized [[tree]]s or [[shrub]]s, mostly of northern [[temperate]] and boreal [[climate]]s.<ref>{{Cite web |title=11 Birch Trees Common to North American Landscapes |url=https://www.thespruce.com/twelve-species-cultivars-of-birch-trees-3269660 |access-date=2022-04-27 |website=The Spruce |language=en}}</ref> The simple [[leaf|leaves]] are alternate, singly or [[doubly serrate]], feather-veined, petiolate and stipulate. They often appear in pairs, but these pairs are really borne on spur-like, two-leaved, lateral [[branchlet]]s.<ref name="Keeler-1900">{{cite book|last=Keeler|first=Harriet L.
|title=Our Native Trees and How to Identify Them|url=https://archive.org/details/ournativetreesa02keelgoog|publisher=Charles Scribner's Sons|year=1900|location =New York|pages=[https://archive.org/details/ournativetreesa02keelgoog/page/n324 295]–297}}</ref> The [[fruit]] is a small [[samara (fruit)|samara]], although the wings may be obscure in some species. They differ from the [[alder]]s (''Alnus'', another genus in the family) in that the female [[catkin]]s are not woody and disintegrate at maturity, falling apart to release the seeds, unlike the woody, cone-like female alder catkins.

The [[Birch bark|bark]] of all birches is characteristically marked with long, horizontal [[lenticel]]s, and often separates into thin, papery plates, especially upon the [[paper birch]].<ref>{{Cite web |last= |first= |title=Recognizing Trees Using Bark |website=Cowling Arboretum [[Carleton College]] |url=https://www.carleton.edu/arboretum/news/recognizing-trees-using-bark/ |access-date=2022-04-27 |language=en-US}}</ref>  Distinctive colors give the common names [[Gray birch|gray]], [[Paper birch|white]], [[black birch (disambiguation)|black]], [[Silver birch|silver]] and [[yellow birch|yellow]] birch to different species.<ref>{{Cite web |title=Trees of the Adirondacks: Yellow Birch {{!}} ''Betula alleghaniensis'' |url=https://www.adirondackvic.org/Trees-of-the-Adirondacks-Yellow-Birch-Betula-alleghaniensis.html |access-date=2022-04-27 |website=Visitor Interpretive Center [[Paul Smith's College]]}}</ref>

The [[bud]]s, forming early and full-grown by [[midsummer]], are all lateral, without a terminal bud forming; the branch is prolonged by the upper lateral bud. The wood of all the species is close-grained with a satiny texture and capable of taking a fine polish; its fuel value is fair.

===Flower and fruit===
The flowers are [[monoecious]], and open with or before the leaves. Once fully grown, these leaves{{clarification needed|reason=?missing text?? The leaves are much larger than stated and not borne witihin the inflorescence|date=October 2024}} are usually {{convert|3|–|6|mm|frac=8}} long on three-flowered clusters in the axils of the scales of drooping or erect [[catkin]]s or aments. Staminate catkins are pendulous, clustered, or solitary in the axils of the last leaves of the branch of the year or near the ends of the short lateral branchlets of the year. They form in early autumn and remain rigid during the winter. The scales of the mature staminate catkins are broadly ovate, rounded, yellow or orange colour below the middle and dark chestnut brown at apex. Each scale bears two bractlets and three sterile flowers, each flower consisting of a sessile, membranous, usually two-lobed, calyx. Each calyx bears four short filaments with one-celled anthers or strictly, two filaments divided into two branches, each bearing a half-anther. Anther cells open longitudinally. The pistillate segments are erect or pendulous, and solitary, terminal on the two-leaved lateral spur-like branchlets of the year. The pistillate scales are oblong-ovate, three-lobed, pale yellow-green often tinged with red, becoming brown at maturity. These scales bear two or three fertile flowers, each flower consisting of a naked ovary. The ovary is compressed, two-celled, and crowned with two slender styles; the ovule is solitary. Each scale bears a single small, winged nut that is oval, with two persistent stigmas at the apex.