{{מיון|
|שם=מטסקוויה
250px
|ממלכה=צומח
|מערכה=מחטנאים
|מחלקה=מחטניים
|סדרה=מחטיים
|משפחה=ברושיים
|תת-משפחה=סקווים
|סוג='''מטסקוויה'''
|מין='''מטסקוויה'''
|שם_מדעי=Metasequoia glyptostroboides
|שימור=שימור CR
}}
'''מטסקוויה''' (מין של תת-משפחת הסקוויים, וגדל באזור סצ'ואן-הוביי שבסין.

==תיאור העץ==
הגזע והעלים דומים לאלו של ביצות. גזע העץ עשוי להיות בצורה מעוקלת אם מניחים אותו על קרקע לא ישרה. העץ גדל עד לגובה של כ-45 מטרים, כאשר קוטר הגזע הוא שני מטרים. כיום (2008) קיימים פרטים של מטסקוויה בני שישים שנה, המגיעים עד לגובה של 25-40 מטרים ולקוטר גזע של כ-1.3 מטרים. 

העלים מסודרים בסידור נגדי זה מול זה משני צידי הגבעול, אורכם 1 עד 3 ס"מ וצבעם הוא ירוק בהיר כשהם רעננים, ואדום-חום בתקופת הנשירה. הכדור-אליפסואיד בקוטר 1.5 - 2.5 ס"מ, ויש להם 16 - 28 קשקשים המסודרים בסידור נגדי של ארבע שורות שהזווית בין כל אחד היא 90 מעלות. אורכם של האצטברולים המואבקים הוא 5 - 6 ס"מ, והם מבשילים כ-9 חודשים לאחר ההאבקה. באזורים שבהם האקלים חם האצטרובלים מייצרים דורבנים ארוכים, אך רק בתחילת האביב.

==היסטוריה==
עד כה התגלו שלושה מינים של מטסקוויה: occidentalis, milleri ו-foxii. המין Metasequoia occidentalis גדל בחלק המערבי של דקוטה הצפונית, וניתן למצוא יערות נרחבים של מטסקוויה באי אקסל הייברג שבצפון קנדה.

שיגרו מיקי תיאר לראשונה את המטסקוויה כחי של הסוג מטסקוויה על ידי ואן צ'ון צ'נג ויו הסן הסו.

{{Taxobox
| fossil_range = Late Cretaceous to Miocene; recent
| status = CR
| status_system = iucn2.3
| image = SJSU Dawn Redwood.JPG
| image_width = 250px
| regnum = Plantae
| divisio = Pinophyta
| classis = Pinopsida
| ordo = Pinales
| familia = Cupressaceae
| genus = '''''Metasequoia'''''
| genus_authority = Miki, 1941
| species = '''''M. glyptostroboides'''''
| binomial = ''Metasequoia glyptostroboides''
| binomial_authority = Hu & W.C.Cheng, 1948
}}

'''''Metasequoia glyptostroboides''''' ('''Dawn Redwood''') is a fast growing conifer family Cupressaceae native to the Sichuan-Hubei region of China. ''Metasequoia'', along with ''Sequoia'', ''Sequoiadendron'' and several other genera, was transferred from the Taxodiaceae family to Cupressaceae using DNA analysis.<ref>Gadek, P.A., Alpers, D.L., Heslewood, M.M., and Quinn, C.J. (2000). Relationships within Cupressaceae ''sensu lato'': A combined morphological and molecular approach. ''American Journal of Botany'', 87(7): 1044-1057.</ref> It is the only living species in the ancient redwood genus '''''Metasequoia''''', but three fossil species are known.

==Appearance==
left|thumb|Dawn Redwood foliage - note opposite arrangement
While the bark and foliage are similar to another closely related redwood genus ''cones are globose to ovoid, 1.5-2.5 cm in diameter with 16-28 scales, arranged in opposite pairs in four rows, each pair at right angles to the adjacent pair; they mature in about 8-9 months after pollination. The pollen cones are 5-6 mm long, produced on long spikes in early spring; they are only produced on trees growing in regions with hot summers.

''Metasequoia'' was first described as a fossil from the Mesozoic Era by Shigeru Miki in 1941, but in 1944 a small stand of an unidentified tree was discovered in China in Modaoxi by Zhan Wang; due to World War II, these were not studied further until 1946 and only finally described as a new living species of ''Metasequoia'' in 1948 by Wan Chun Cheng and Hu Hsen Hsu. In 1948 the Arnold Arboretum of Harvard University sent an expedition to collect seeds and, soon after, seedling trees were distributed to various universities and arboreta worldwide for growth trials. 

In the late 1980s, it was discovered that many of the second generation trees in cultivation suffered from inbreeding depression (extremely low genetic variability) which could lead to increased susceptibility to disease and reproductive failure. This was because most of the trees were grown from seeds and cuttings derived from as few as three trees that the Arnold Arboretum had used as its source. More widespread seed-collecting expeditions in China in the 1990s sought to resolve this problem and restore genetic diversity to cultivated ''Metasequoia''.

''Metasequoia'' has proved an easy tree to grow in temperate regions, and is now widely planted as an ornamental tree. Planted specimens have already reached 25-40 m in height and 1-1.3 m in diameter, despite being in cultivation for under 60 years. This rapid rate of growth has led to consideration for using the tree in forestry plantations.

It has been discovered that ''Metasequoia'' will thrive in standing water, much like the baldcypress, and if left branched to the ground in full sun, will develop the large, contorted boles that have made it famous. Limbing at an early age will prohibit this formation later on.

==Paleontology==
''Metasequoia'' redwood fossils are known from many areas in the Northern Hemisphere; over 20 fossil species have been named (some were even identified as the genus ''Sequoia''), but are considered as just three species, ''M. foxii'', ''M. milleri'', and ''M. occidentalis'' (Farjon 2005). During the Paleocene-Eocene Thermal Maximum, extensive forests of ''Metasequoia'' occurred as far north as Axel Heiberg Island [http://edisk.fandm.edu/chris.williams/pubs/williams_etal_2003b.pdf] (northern Canada) at around 80°N latitude. Large petrified trunks and stumps of the extinct ''Metasequoia occidentalis'' (sometimes identified as ''Sequoia occidentalis'') also make up the major portion of Tertiary fossil plant material in the badlands of western North Dakota in the United States.

The trees are well known from late Cretaceous to Miocene strata, but no fossils are known after that. Before its discovery, the taxon was believed to have become extinct during the Miocene; when it was discovered , it was heralded as a "living fossil".