Coastal Redwood: Sequoia sempervirens and Dawn Redwood: Metasequoia glyptostoboides

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Interactive Botanical tour

Point No. 11

Species: Sequoia sempervirens (Lamb. ex D. Don) Endl. & Metasequoia glyptostroboides Hu & W.C. Cheng

Family: Cupressaceae

Coastal redwood (Sequoia sempervirens) and Dawn Redwood (Metasequoia glyptostroboides) are part of the Cupressaceae family among over 130 other species [1]. Cupressaceae is a conifer family of evergreen trees and shrubs.

 

Sequoia sempervirens is found in the wild along the Western Coast of the USA. The tallest living tree on the planet is of this species and reaches over 110 metres in height. This specimen is found in California, USA and is likely between 600 - 800 years old [2]. The individual found at the University of Pretoria is much younger; it was likely planted in the early 1990s. However, S. sempervirens is an incredibly fast-growing tree and is therefore useful in the forestry industry.

 

Coastal redwood is monoecious, meaning it contains both male and female reproductive organs within one individual. Furthermore, the cones produced by S. sempervirens do not tend to attract attention and are rather small. After pollination, cones of both sexes are formed. Female cones will mature after fertilisation and produce roughly 200 seeds per cone [3]. In general, the tree forms a symmetrical canopy in a pyramidal shape. The needle-like leaves are arranged alternately in a spiral [4]. They do not change colour as the seasons change and do not fall in autumn. The wood formed by this tree is very light to bright red.

Figure 1: Coast redwood (Sequoia sempervirens) leaves (top left by  rosie1975,, iNaturalist), female cones (top right, by FreckLes, iNaturalist), total tree-span (bottom left by Daniel Das, iNaturalist) and tree bark (bottom right, by then, iNaturalist).

Its smaller relative, Metasequoia glyptostroboides, only grows up to 60 metres in height. This species was thought to have been extinct for 45 million years, and was described using fossils. The species may have lived in North America, but it is thought to have disappeared from the continent during the last Ice Age. It became a living fossil after it was rediscovered in the 1940s happily growing in China [5]. Dawn redwood is native to China, more specifically the region between the Hubei and Hunan provinces. M. glyptostroboides is the only living species left in the genus and is Critically Endangered. It was thought to be extinct until 1947 when a group of scientists found a living individual in Sichuan, China. The specimen on campus was planted in the 1960s and was propagated from a piece of a specimen from China.

 

This tree also forms a symmetrical canopy of pyramidal shape. However, the leaf arrangement in M. glyptostroboides is different from that of its relative. Leaves are linear in shape and show an opposite arrangement [6]. Furthermore, dawn redwood is deciduous, meaning that the leaves are lost in autumn [7]. Before they fall, leaves turn from green to an orange-yellow colour. The base of dawn redwood is red orange to brown in colour which makes this tree such a spectacular site to see [8].

 

Figure 2: Dawn redwood (Metasequoia glyptostroboides) leaves (top left, by tracy muller, iNaturalist), rounded immature female cones (top right, by Markus Krieger, iNaturalist), tree span (bottom left, by rambee, iNaturalist) and tree bark (bottom right, by  sue525, iNaturalist).

 

 

Text prepared by Sapphire de Zoete & Jordan Kyle Roux, BOT 366 class of 2022.

 

 

Cited sources:

1. The Editors of Encyclopaedia Britannica. (1998). Cupressaceae. Retrieved from Britannica: https://www.britannica.com/plant/Cupressaceae

 

2. Tallest tree living. (2019). Retrieved from Guinness World Records: https://www.guinnessworldrecords.com/world-records/tallest-tree-living

 

3. Boles, J. (n.d.). How Do Sequoia Trees Reproduce? Retrieved from eHow: https://www.ehow.com/about_6643082_do-sequoia-trees-reproduce_.html

 

4. Gilman, E. F., & Watson, D. G. (1994). Sequoia sempervirens Coast Redwood. Gainesville: University of Florida.
    

 

5.  Prance, G. T. (2004). BIODIVERSITY | Endangered Species of Trees. In J. Burley, Encyclopedia of Forest Sciences (pp. 44-51). Elsevier: Oxford.

 

6. Metasequoia glyptostroboides. (n.d.). Retrieved from North Carolina Extension Gardener Plant Toolbox: https://plants.ces.ncsu.edu/plants/metasequoia-glyptostroboides/

 

7. Metasequoia Genus (dawn redwood). (n.d.). Retrieved from American Conifer Society: https://conifersociety.org/conifers/metasequoia/

 

8. Gilman, E. F., & Watson, D. G. (1994). Metasequoia glyptostroboides Dawn Redwood. Gainesville: University of Florida.
    

‌Images: some rights reserved (CC BY-NC), iNaturalist

rosie1975, iNaturalist,  https://www.inaturalist.org/observations/179460321 

FreckLes, iNaturalist,  https://www.inaturalist.org/observations/175872969

Daniel Das, iNaturalist,  https://www.inaturalist.org/observations/174369622

then, iNaturalist, https://www.inaturalist.org/observations/174338619

tracymuller, iNaturalist, https://www.inaturalist.org/observations/179222385

Markus Krieger, iNaturalist, https://www.inaturalist.org/observations/179299849

rambee, iNaturalist, https://www.inaturalist.org/observations/178989004

sue525, iNaturalist, https://www.inaturalist.org/observations/169573734