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Earliest rooting system and root : shoot ratio from a new Zosterophyllum plant
Author(s) -
Hao Shougang,
Xue Jinzhuang,
Guo Dali,
Wang Deming
Publication year - 2010
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2009.03056.x
Subject(s) - shoot , biology , botany , root (linguistics) , root system , horticulture , linguistics , philosophy
Summary• The enhanced chemical weathering by rooted vascular plants during the Silurian–Devonian period played a crucial role in altering global biogeochemical cycles and atmospheric environments; however, the documentation of early root morphology and physiology is scarce because the existing fossils are mostly incomplete. • Here, we report an entire, uprooted specimen of a new Zosterophyllum Penhallow, named as Z . shengfengense , from the Early Devonian Xitun Formation (Lochkovian, c. 413 Myr old) of Yunnan, south China. This plant has the most ancient known record of a rooting system. • The plant consists of aerial axes of 98 mm in height, showing a tufted habit, and a rhizome bearing a fibrous‐like rooting system, c. 20 mm in length. The rhizome shows masses of branchings, which produce upwardly directed aerial axes and downwardly directed root‐like axes. • The completeness of Z . shengfengense made it possible to estimate the biomass allocation and root : shoot ratio. The root : shoot ratio of this early plant is estimated at a mean value of 0.028, and the root‐like axes constitute only c. 3% of the total biomass. Zosterophyllum shengfengense was probably a semi‐aquatic plant with efficient water use or a strong uptake capacity of the root‐like axes.