Scientific name: Dipteris conjugata
A living fossil with Jurassic features, the broad-leaf fern is the only dipteridaceae plant in Taiwan. The plant usually spreads out with its two fan-shaped leaves along thin rock walls, looking like a broken umbrella. Thus, it is known as “the broken umbrella fern” in Mandarin. It is also called “the nature’s compass” because it likes to face the Sun.
Coupled Dipteris (Dipteris conjugata) in Taoyuan Valley
by Taiwan Ecotourism Association (TEA) 2022.6.23
Bumping into Coupled Dipteris (Dipteris conjugata) on the top of steep cliff facing east in Taoyuan Valley, and then I recalled it is also seen on the same cliff line in northern side, Caoling Historic Trail.
Evolution of Dipteridaceae reached its peak in Mesozoic Era (Middle Life Era, 225~65 million years ago ) and it spread around the world, from the Arctic Circle to the South Pole, across all the continents. As we can learn from fossil, there were about 6 genera and 60 species of Dipteridaceae, while only 1 genus and 6 species are left today. Currently, Dipteridaceae has limited distribution in South East Asia and its northern distributional limit is in northern Taiwan, Ishigaki Island and Iriomotejima Island. Distribution of Dipteridaceae is quite scattered nowadays, and it only grows on cliff, mountain ridges, clearings or under forest margins with sufficient light. Its ecological habit has not changed since Mesozoic Era. Mesozoic Era is commonly known as the age of dinosaurs. During this period, Gymnosperm such as Pinaceae (pine family), Taxodiaceae, Cupressaceae, and Cycadaceae were dominant tree species, and some tree ferns of Dicksoniaceae might occasionally stood there too. The landscape was like current savanna in Africa but with higher humidity. Dipteridaceae grew a lot in such well-lit environment. Broad-leaved tree within the group of Angiospermae started to evolve 100 million years ago, and it gradually dominated the earth 65 million years ago. Broad-leaved forests are multilayered with epiphytes and vines/climbers, thus Dipteridaceae which requires open and high relative humidity has to shrink back to a very limited area.
Through learning stories of Coupled Dipteris in Taoyuan Valley, we can tell environmental changes in recent 200~100 million years; and most important of all, it is ensured that Taiwan has environmental condition of that in 200~100 million years ago.