Ginkgos (Order Ginkgoales, clade Spermatophyta) are represented at the present day by a single species, Ginkgo biloba, also known as the maidenhair tree. The leaves of this tree have a very characteristic shape, as illustrated in Figure 3 below. The order contains around 15 fossil genera (Encyclopaedia Britannica).
No phylogenetic trees of the Ginkgoales have been published recently. The time tree shown below is a combination of two trees, published in 2003 and 2004 respectively:
No phylogenetic trees of the Ginkgoales have been published recently. The time tree shown below is a combination of two trees, published in 2003 and 2004 respectively:
Figure 1. Summarized phylogenetic tree of the stem-Ginkgoales
The oldest known member of the stem-Ginkgoales is Trichopitys heteromorpha, described from Autunian (latest Carboniferous to Early Permian) sediments near Lodève in southern France (Florin, 1949; Zhou, 2003). Unfortunately, no images of this species are available in the public domain, but several other members of the stem group are illustrated below (for a larger view, click on image):
Figure 2. Images of stem-Ginkgoales
The above images are ordered from most basal to most crownward. The most obvious trend can be seen in the shape of the leaves, which in the most basal genera are quite unlike those of extant ginkgos. The basal genera are recognized as ginkgoaleans from their female reproductive organs as described by Zhou (2009), who provides a helpful review of ginkgoalean evolution.
The ginkgo crown group comprises only one species, the extant Ginkgo biloba (illustrated below and in the header above), which has also been found as fossils in Pliocene sediments in southwestern Japan (Uemura, 1997).
The ginkgo crown group comprises only one species, the extant Ginkgo biloba (illustrated below and in the header above), which has also been found as fossils in Pliocene sediments in southwestern Japan (Uemura, 1997).
Figure 3. Ginkgo biloba, photographed in Botanical Garden Jevremovac, Belgrade, Serbia
As indicated in Figure 1, the stem-to-crown transition of the Ginkgoales took place over a period of at least 290 million years, from latest Carboniferous (or Early Permian) to Pliocene time.
References
Doyle, J. A. (2006). Seed ferns and the origin of angiosperms. The Journal of the Torrey Botanical Society, 133(1), 169-209.
Florin, R. (1949). The Morphology of Trichopitys heteromorpha Saporta, a Seed-plant of Palaeozoic Age, and the Evolution of the Female Flowers in the Ginkgionae. Acta horti Bergiani, Band 15, No. 5.
Jin, B., Tang, L., Lu, Y., Wang, D., Zhang, M., & Ma, J. (2012). Temporal and spatial characteristics of male cone development in Metasequoia glyptostroboides Hu et Cheng. Plant signaling & behavior, 7(12), 1687-1694.
Uemura, K. (1997). Cenozoic history of Ginkgo in east Asia. In Ginkgo Biloba A Global Treasure: From Biology to Medicine (pp. 207-221). Tokyo: Springer Japan.
Zheng, S., & Zhou, Z. (2004). A new Mesozoic Ginkgo from western Liaoning, China and its evolutionary significance. Review of Palaeobotany and Palynology, 131(1-2), 91-103.
Zhou, Z. (2003). Mesozoic ginkgoaleans: phylogeny, classification and evolutionary trends. Acta Botanica Yunnanica, 25(4), 377-396.
Zhou, Z. Y. (2009). An overview of fossil Ginkgoales. Palaeoworld, 18(1), 1-22.
Florin, R. (1949). The Morphology of Trichopitys heteromorpha Saporta, a Seed-plant of Palaeozoic Age, and the Evolution of the Female Flowers in the Ginkgionae. Acta horti Bergiani, Band 15, No. 5.
Jin, B., Tang, L., Lu, Y., Wang, D., Zhang, M., & Ma, J. (2012). Temporal and spatial characteristics of male cone development in Metasequoia glyptostroboides Hu et Cheng. Plant signaling & behavior, 7(12), 1687-1694.
Uemura, K. (1997). Cenozoic history of Ginkgo in east Asia. In Ginkgo Biloba A Global Treasure: From Biology to Medicine (pp. 207-221). Tokyo: Springer Japan.
Zheng, S., & Zhou, Z. (2004). A new Mesozoic Ginkgo from western Liaoning, China and its evolutionary significance. Review of Palaeobotany and Palynology, 131(1-2), 91-103.
Zhou, Z. (2003). Mesozoic ginkgoaleans: phylogeny, classification and evolutionary trends. Acta Botanica Yunnanica, 25(4), 377-396.
Zhou, Z. Y. (2009). An overview of fossil Ginkgoales. Palaeoworld, 18(1), 1-22.
Image credits – stem-Ginkgoales
- Header (Ginkgo biloba photographed in Tyler Arboretum, Texas): Photo (c)2007 Derek Ramsey (Ram-Man), GFDL 1.2 <http://www.gnu.org/licenses/old-licenses/fdl-1.2.html>, via Wikimedia Commons
- Figure 2 (Yimaia recurva): Peter R. Crane, Pollyanna von Knorring, CC BY 4.0 <https://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons
- Figure 2 (Umaltolepis spp.): Open Access article Herrera, F., Shi, G., Ichinnorov, N., Takahashi, M., Bugdaeva, E. V., Herendeen, P. S., & Crane, P. R. (2017). The presumed ginkgophyte Umaltolepis has seed-bearing structures resembling those of Peltaspermales and Umkomasiales. Proceedings of the National Academy of Sciences, 114(12), E2385-E2391.
- Figure 2 (Umaltolepis mongoliensis): Open Access article Herrera, F., Shi, G., Ichinnorov, N., Takahashi, M., Bugdaeva, E. V., Herendeen, P. S., & Crane, P. R. (2017). The presumed ginkgophyte Umaltolepis has seed-bearing structures resembling those of Peltaspermales and Umkomasiales. Proceedings of the National Academy of Sciences, 114(12), E2385-E2391.
- Figure 2 (Schmeissneria sinensis, fossil): Open Access article Wang, X., Duan, S., Geng, B., Cui, J., & Yang, Y. (2007). Schmeissneria: a missing link to angiosperms?. BMC evolutionary Biology, 7, 1-13.
- Figure 2 (female structure of Schmeissneria sinensis): Open Access article Wang, X., Duan, S., Geng, B., Cui, J., & Yang, Y. (2007). Schmeissneria: a missing link to angiosperms?. BMC evolutionary Biology, 7, 1-13.
- Figure 2 (Ginkgo yimaensis): Ginkgob, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
- Figure 2 (Ginkgo apodes): Ginkgob, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
- Figure 2 (Ginkgo adiantoides, fossil): Ghedoghedo, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
- Figure 2 (Ginkgo adiantoides, life restoration): Ginkgob, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
- Figure 3 (Ginkgo biloba): Marija Gajić, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons