Editing Liriodendron (section)

== Description ==

''Liriodendron'' trees are easily recognized by their [[leaf|leaves]], which are distinctive, having four lobes in most cases and a cross-cut notched or straight apex. Leaf size varies from 8–22&nbsp;cm long and 6–25&nbsp;cm wide. They are deciduous in the vast majority of cases for both species; however, each species has a [[semi-deciduous]] variety at the southern limit of its range in [[Florida]] and [[Yunnan]] respectively.<ref>{{Cite journal|doi=10.3390/f10010013|doi-access=free|title=RAD-Seq Data Point to a Distinct Split in Liriodendron (Magnoliaceae) and Obvious East–West Genetic Divergence in L. Chinense|year=2018|last1=Zhong|first1=Yongda|last2=Yang|first2=Aihong|last3=Liu|first3=Shujuan|last4=Liu|first4=Lipan|last5=Li|first5=Yanqiang|last6=Wu|first6=Zhaoxiang|last7=Yu|first7=Faxin|journal=Forests|volume=10|page=13}}</ref> The tulip tree is often a large tree, 18–60 m high and 60–120&nbsp;cm in diameter. The stoutest well-authenticated Tulip tree was the Liberty Tree in [[Maryland]] which was {{convert|21.5|ft|m|abbr=off|sp=us}} in circumference.<ref>{{cite web|  url= https://www.nativetreesociety.org/projects/middleton/middletonproj.htm | title= Middleton Oak SC and Sag Branch Tulip GSMNP Project| date= February 21, 2004 | access-date= April 24, 2008}}</ref> It died in 1999. The tree is known to reach the height of {{convert|191.8|ft|m|abbr=off|sp=us}},<ref>{{ cite web|  url= http://www.landmarktrees.net/spring%202011%20latest%20news.html | title= Landmark Trees | date= May 6, 2011 | access-date= December 20, 2011}}</ref> in groves where they compete for sunlight, somewhat less if growing in an open field. Its trunk is usually columnar, with a long, branch-free bole forming a compact, rather than open, conical crown of slender branches. It has deep roots that spread widely.<ref>Michigan Trees</ref>{{Full citation needed|date=May 2025}} 

Leaves are slightly larger in ''L. chinense,'' compared to ''L. tulipifera'', but with considerable overlap between the species; the [[Petiole (botany)|petiole]] is 4–18&nbsp;cm long. Leaves on young trees tend to be more deeply lobed and larger in size than those on mature trees. In autumn, the leaves turn yellow, or brown and yellow. Both species grow rapidly in rich, moist soils of temperate climates. They [[Hybrid (biology)|hybrid]]ize easily, producing ''L. x sinoamericanum'' cultivars.{{cn|date=June 2024}}

[[Flower]]s are 3–10&nbsp;cm in diameter and have nine [[tepal]]s — three green outer [[sepals]] and six inner [[petals]] which are yellow-green, with an orange flare at the base in ''L. tulipifera'' and ''L. x sinoamericanum''. They start forming after around 15 years and are superficially similar to a [[tulip]] in shape, hence the tree's name. Flowers of ''L. tulipifera'' have a faint [[cucumber]] odor. The [[stamen]]s and [[pistil]]s are arranged spirally around a central spike or [[gynaecium]]; the stamens fall off, and the pistils become the [[Samara (fruit)|samara]]s. The [[fruit]] is a cone-like aggregate of samaras 4–9&nbsp;cm long, each of which has a roughly tetrahedral seed with one edge attached to the central conical spike and the other edge attached to the wing.{{cn|date=June 2024}}
[[File:Tree Types and Barks 003.jpg|thumb|right|190px|Tulip tree bark]]
[[File:Liriodendron tulipifera flower.jpg|thumb|right|190px|Tulip tree flower]]
[[File:TinicumParkTuliptree.jpg|thumb|right|190px|Tuliptrees can be very large. This 130-footer in Pennsylvania with a 5-foot trunk dwarfs a group of mature oaks and maples.]]
===Cytology===
The chromosome count of ''Liriodendron chinense'' is 2n = 38.<ref name = "Flora of China a">''Liriodendron chinense'' in Flora of China @ efloras.org. (n.d.). Retrieved May 31, 2025, from http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200008462</ref>