View source for Liriodendron tulipifera

{{SPlantbox
|familia=Magnoliaceae
|genus=Liriodendron
|species=tulipifera
|taxo_author=L.
|common_name=Tulip tree, American tulip tree, tuliptree, tulip poplar, yellow poplar
|name_ref=Wikipedia
|habit=tree
|habit_ref=Complete Landscaping - ISBN 9780376009272
|Min ht box=60
|Min ht metric=ft
|Max ht box=90
|Max ht metric=ft
|height_ref=Complete Landscaping - ISBN 9780376009272
|lifespan=perennial
|life_ref=Complete Landscaping - ISBN 9780376009272
|exposure=sun
|water=moist
|water_ref=Complete Landscaping - ISBN 9780376009272
|features=deciduous, flowers, fall color
|flower_season=late spring
|Temp Metric=°F
|min_zone=4
|usda_ref=Complete Landscaping - ISBN 9780376009272
|max_zone=9.5
|image=Liriodendron tulipifera (arbre) - Laeken.JPG
|image_width=200
}}
'''''Liriodendron tulipifera''''', commonly known as the '''tulip tree''', '''American tulip tree''', '''tuliptree''', '''tulip poplar''' or '''yellow poplar''', is the [[Western Hemisphere]] representative of the two-[[species]] [[genus]] ''[[Liriodendron]],'' and the tallest eastern [[hardwood]]. It is native to eastern North America from [[Southern Ontario|Southern]] [[Ontario]] and [[Illinois]] eastward across southern [[New England]] and south to central [[Florida]] and [[Louisiana]]. It can grow to more than 50 m (165&nbsp;feet) in virgin cove forests of the [[Appalachian Mountains]], often with no limbs until it reaches 25–30 m (80–100&nbsp;feet) in height, making it a very valuable [[timber]] tree. It is fast-growing, without the common problems of weak [[wood]] strength and short lifespan often seen in fast-growing species. April marks the start of the flowering period in the southern USA (except as noted below); trees at the northern limit of cultivation begin to flower in June. The flowers are pale green or yellow (rarely white), with an orange band on the [[tepals]]; they yield large quantities of [[nectar]].  The tulip tree is the [[list of U.S. state trees|state tree]] of [[Indiana]], [[Kentucky]], and [[Tennessee]]. 

The tulip tree is one of the largest of the native trees of the eastern United States, known to reach the height of {{convert|190|ft|m|0}}, with a trunk {{convert|10|ft|m|0}} in diameter; its ordinary height is {{convert|70|ft|m|0}} to {{convert|100|ft|m|0}}. It prefers deep, rich, and rather moist soil; it is common, though not abundant, nor is it solitary. Its roots are fleshy.  Growth is fairly rapid, and the typical form of its head is conical.<ref name=Keeler>{{cite book
  | last =Keeler
  | first =Harriet L.
  | title =Our Native Trees and How to Identify Them
  | publisher =Charles Scriber's Sons
  | year =1900
  | location =New York
  | pages =14–19 }}</ref>

The bark is brown, and furrowed. The branchlets are smooth, and lustrous, initially reddish, maturing to dark gray, and finally brown.  Aromatic and bitter.
The wood is light yellow to brown, and the sapwood creamy white; light, soft, brittle, close, straight-grained.  Sp. gr., 0.4230; weight of cu. ft., 26.36&nbsp;lbs.
* Winter buds: Dark red, covered with a bloom, obtuse; scales becoming conspicuous stipules for the unfolding leaf, and persistent until the leaf is fully grown.  Flower-bud enclosed in a two-valved, caducous bract.
The alternate leaves are simple, pinnately veined, measuring five to six inches long and wide. They have four lobes, and are heart-shaped or truncate or slightly wedge-shaped at base, entire, and the apex cut across at a shallow angle, making the upper part of the leaf look square; midrib and primary veins prominent.  They come out of the bud recurved by the bending down of the [[Petiole_(botany)|petiole]] near the middle bringing the apex of the folded leaf to the base of the bud, light green, when full grown are bright green, smooth and shining above, paler green beneath, with downy veins.  In autumn they turn a clear, bright yellow.  [[Petiole_(botany)|Petiole]] long, slender, angled.
[[File:Liriodendron tulipifera 'Mediopictum' JPG1c.jpg|thumb|''Liriodendron tulipifera'' 'Mediopictum' leaves (autumn).]]
* Flowers: May.  Perfect, solitary, terminal, greenish yellow, borne on stout [[Peduncle_(botany)|peduncles]], an inch and a half to two inches long, cup-shaped, erect, conspicuous.  The bud is enclosed in a sheath of two triangular bracts which fall as the blossom opens.
* Calyx: Sepals three, imbricate in bud, reflexed or spreading, somewhat veined, early deciduous.
* Corolla: Cup-shaped, petals six, two inches long, in two rows, imbricate, hypogynous, greenish yellow, marked toward the base with yellow.  Somewhat fleshy in texture.
* Stamens: Indefinite, imbricate in many ranks on the base of the receptacle; filaments thread-like, short; anthers extrorse, long, two-celled, adnate; cells opening longitudinally.
* Pistils: Indefinite, imbricate on the long slender receptacle.  Ovary one-celled; style acuminate, flattened; stigma short, one-sided, recurved; ovules two.
* Fruit: Narrow light brown cone, formed by many samara-like [[carpel]]s which fall, leaving the axis persistent all winter.  September, October.<ref name=Keeler />

[[File:Liriodendron tulipifera flower.jpg|thumb|''Liriodendron tulipifera'' flower]]

A description from ''[[Our native trees and how to identify them]]'' by [[Harriet Louise Keeler]]<ref name=Keeler />:

{{quote|The leaves are of unusual shape and develop in a most peculiar and characteristic manner.  The leaf-buds are composed of scales as is usual, and these scales grow with the growing shoot.  In this respect the buds do not differ from those of many other trees, but what is peculiar is that each pair of scales develops so as to form an oval envelope which contains the young leaf and protects it against changing temperatures until it is strong enough to sustain them without injury.  When it has reached that stage the bracts separate, the tiny leaf comes out carefully folded along the line of the midrib, opens as it matures, and until it becomes full grown the bracts do duty as stipules, becoming an inch or more in length before they fall.  The leaf is unique in shape, its apex is cut off at the end in a way peculiarly its own, the petioles are long, angled, and so poised that the leaves flutter independently, and their glossy surfaces so catch and toss the light that the effect of the foliage as a whole is much brighter than it otherwise would be.

The flowers are large, brilliant, and on detached trees numerous.  Their color is greenish yellow with dashes of red and orange, and their resemblance to a tulip very marked.  They do not droop from the spray but sit erect.  The fruit is a cone two to three inches long, made of a great number of thin narrow scales attached to a common axis.  These scales are each a carpel surrounded by a thin membranous ring.  Each cone contains sixty or seventy of these scales, of which only a few are productive.  These fruit cones remain on the tree in varied states of dilapidation throughout the winter.}}

{{Inc|
Liriodendron tulipifera, Linn. Tall tree, to 150, rarely to 190 ft., with a trunk to 10 ft. diam., often destitute of branches for a considerable height, glabrous: lvs. about as broad as long, with 2 lobes at the truncate and notched apex and 2-4 lobes at the base, bluish green above, pale or glaucous beneath, 5-6 in. long: fls. greenish yellow, marked orange within at the base, 1 ½-2 in. long; petals ovate or oval; fertile carpels acute. May, June. Mass, to Wis., south to Fla. and Miss.Var. pyramidale, Lav. (var. fastigiatum, Hort.). With upright branches, forming a narrow pyramid. Var. integrifolium, Kirchn. Lvs. rounded at the base without lobes. Var. obtusilobum, Pursh. Lvs. with only 1 rounded lobe on each side of the base. Var. contortum, Goeschke. Lvs. with 2 lobes on each side, twisted so that the upper lobes often form a right angle to the lower ones. There are also several vars. with variegated lvs., of which var. aureomarginatum, Hort. (var. panache, Hort.), with lvs. edged yellow, is one of the best. F.S. 19:2025; 20:2081.—In the Middle West, liriodendron is universally known as whitewood. To lumbermen in the East it is known as poplar and tulip poplar.
}}