RESUMEN
Lycopsids are a minor component of current terrestrial herbaceous floras. However, lycopsid fossil diversity shows a great diversity and disparity including heterosporous woody plants, e.g. the giant isoetaleans that populated the extensive Pennsylvanian wetlands. The earliest known isoetaleans come from late Devonian localities from China. Here, we describe Lilingostrobus chaloneri gen. et sp. nov., a new isoetalean lycopsid from the Upper Devonian (Famennian) Xikuangshan Formation of China (Hunan Province, South China), which adds to the already impressive diversity of the Devonian lycopsids from China. Lilingostrobus shows an unusual combination of characters. This new plant is pseudoherbaceous, with a possible tufted habit, and consists of narrow axes with rare isotomies. The stem includes small quantities of secondary xylem. Each fertile axis bears one terminal strobilus comprising sporophylls ending in a very long upturned lamina. Microspores and putative megaspores have been found, but whether the plant has mono- or bisporangiate strobili is unknown. Importantly, our cladistic analysis identifies Lilingostrobus as a direct precursor of Isoetales, which provides new insights into the early evolution of lycopsids.
Asunto(s)
Lycopodiaceae/anatomía & histología , Filogenia , Tallos de la Planta/anatomía & histología , Xilema/anatomía & histología , Evolución Biológica , China , Extinción Biológica , Fósiles/historia , Historia Antigua , Lycopodiaceae/clasificación , Lycopodiaceae/fisiología , Tallos de la Planta/clasificación , Tallos de la Planta/fisiología , Humedales , Xilema/fisiología , Xilema/ultraestructuraRESUMEN
Seven species were reported as new records of Jiangxi province, which collected from Wugongshan region, including Huperzia kunmingensis(Lycopodiaceae), Hydrangea mangshanensis(Saxifragaceae), Itea glutinosa(Saxifragaceae), Stellaria monosperma var. japonica(Lycopodiaceae), Youngia pratti(Compositae), and Calanthe henryi(Orchidaceae), Collabium formosanum(Orchidaceae). Among these species, H. kunmingensis, H. mangshanensis, I. glutinosa, Y. pratti and C. henryi are endemic in China. C. henryi is stenotopic distribution in China and regarded as vulnerable endangered plant by IUCN. The report is of great significance to the plant diversity and floristic composition in Jiangxi. All the specimens examined are preserved in Jishou University (JIU) and Sun yat-sen University (SYS).
Asunto(s)
Asteraceae/clasificación , Lycopodiaceae/clasificación , Orchidaceae/clasificación , Plantas Medicinales/clasificación , Saxifragaceae/clasificación , ChinaRESUMEN
The genus Diphasiastrum includes at least 23 species distributed primarily across the northern temperate and subarctic areas of the world. These plants produce an array of lycopodium alkaloids, and some species such as Diphasiastrum complanatum have been used in traditional medicine for ages for various conditions. Hybridization is common in this group of plants and they have always been a challenge for taxonomists and other scientists studying them. To date, 11 Diphasiastrum species have been reported to produce lycopodium alkaloids. In this review, reported alkaloids and their distribution patterns across these species along with taxonomical and bioactivity considerations are reviewed and discussed.