Amentotaxus is a genus of conifers (catkin-yews) comprising five species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to subtropical Southeast Asia, from Taiwan west across southern China to Assam in the eastern Himalaya, and south to Vietnam. The species are evergreenshrubs and small trees reaching 2–15 m tall.
The leaves are spirally arranged on the shoots, but twisted at the base to lie in two flat ranks (except on erect leading shoots); they are linear-lanceolate, 4–12 cm long and 6–10 mm broad, soft in texture, with a blunt tip, green above, and with two conspicuous white stomatal bands below. They differ from the related genus Cephalotaxus in the broader leaves, and from Torreya by the blunt, not spine-tipped leaves.
The species can be either monoecious or dioecious; when monoecious, the male and female cones are often on different branches. The male (pollen) cones are catkin-like, 3–15 cm long, grouped in clusters of two to six together produced from a single bud. The female (seed) cones are single or grouped a few together on short stems; minute at first, they mature in about 18 months to a drupe-like structure with the single large nut-like seed 1.5–3 cm long surrounded by a fleshy covering, orange to red at full maturity; the apex of the seed usually protrudes slightly out of the fleshy covering.
The oldest fossils that are recognisable to the genus are from the Middle-Late JurassicDaohugou Bed of China.[1]
China: Fujian, southern Gansu, Guangdong, Guangxi, Guizhou, western Hubei, Hunan, Jiangsu, north-western Jiangxi, central and south-eastern Sichuan, south-eastern Tibet and southern Zhejiang
^Dong, Chong; Shi, Gongle; Herrera, Fabiany; Wang, Yongdong; Herendeen, Patrick S; Crane, Peter R (2020-06-18). "Middle–Late Jurassic fossils from northeastern China reveal morphological stasis in the catkin-yew". National Science Review. 7 (11): 1765–1767. doi:10.1093/nsr/nwaa138. ISSN 2095-5138. PMC8288717. PMID 34691509.
^Stull, Gregory W.; Qu, Xiao-Jian; Parins-Fukuchi, Caroline; Yang, Ying-Ying; Yang, Jun-Bo; Yang, Zhi-Yun; Hu, Yi; Ma, Hong; Soltis, Pamela S.; Soltis, Douglas E.; Li, De-Zhu; Smith, Stephen A.; Yi, Ting-Shuang; et al. (2021). "Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms". Nature Plants. 7 (8): 1015–1025. bioRxiv10.1101/2021.03.13.435279. doi:10.1038/s41477-021-00964-4. PMID 34282286. S2CID 232282918.
amentotaxus, genus, conifers, catkin, yews, comprising, five, species, treated, either, cephalotaxaceae, taxaceae, when, that, family, considered, broad, sense, genus, endemic, subtropical, southeast, asia, from, taiwan, west, across, southern, china, assam, e. Amentotaxus is a genus of conifers catkin yews comprising five species treated in either the Cephalotaxaceae or in the Taxaceae when that family is considered in a broad sense The genus is endemic to subtropical Southeast Asia from Taiwan west across southern China to Assam in the eastern Himalaya and south to Vietnam The species are evergreen shrubs and small trees reaching 2 15 m tall AmentotaxusTemporal range Middle Jurassic Recent PreꞒ Ꞓ O S D C P T J K Pg N Fossil Amentotaxus needles Scientific classification Kingdom Plantae Clade Tracheophytes Clade Gymnospermae Division Pinophyta Class Pinopsida Order Cupressales Family Taxaceae Genus AmentotaxusPilg Type species Amentotaxus argotaenia Hance Pilg Species A argotaenia A assamica A formosana A poilanei A yunnanensis Amentotaxus formosana The leaves are spirally arranged on the shoots but twisted at the base to lie in two flat ranks except on erect leading shoots they are linear lanceolate 4 12 cm long and 6 10 mm broad soft in texture with a blunt tip green above and with two conspicuous white stomatal bands below They differ from the related genus Cephalotaxus in the broader leaves and from Torreya by the blunt not spine tipped leaves The species can be either monoecious or dioecious when monoecious the male and female cones are often on different branches The male pollen cones are catkin like 3 15 cm long grouped in clusters of two to six together produced from a single bud The female seed cones are single or grouped a few together on short stems minute at first they mature in about 18 months to a drupe like structure with the single large nut like seed 1 5 3 cm long surrounded by a fleshy covering orange to red at full maturity the apex of the seed usually protrudes slightly out of the fleshy covering The oldest fossils that are recognisable to the genus are from the Middle Late Jurassic Daohugou Bed of China 1 Extant species editPhylogeny of Amentotaxus 2 3 Amentotaxus A formosana Li A argotaenia Hance Pilger A poilanei Ferre amp Rouane Ferguson A hatuyenensis Nguyen A yunnanensis Li Image Scientific name Common name Distribution nbsp Amentotaxus argotaenia Catkin yew China Fujian southern Gansu Guangdong Guangxi Guizhou western Hubei Hunan Jiangsu north western Jiangxi central and south eastern Sichuan south eastern Tibet and southern Zhejiang Amentotaxus assamica Assam catkin yew India nbsp Amentotaxus formosana Taiwan catkin yew Taiwan Amentotaxus hatuyenensis Vietnam Amentotaxus poilanei Poilane s catkin yew Vietnam nbsp Amentotaxus yunnanensis Yunnan catkin yew Laos Vietnam and Guizhou and Yunnan in ChinaReferences edit Dong Chong Shi Gongle Herrera Fabiany Wang Yongdong Herendeen Patrick S Crane Peter R 2020 06 18 Middle Late Jurassic fossils from northeastern China reveal morphological stasis in the catkin yew National Science Review 7 11 1765 1767 doi 10 1093 nsr nwaa138 ISSN 2095 5138 PMC 8288717 PMID 34691509 Stull Gregory W Qu Xiao Jian Parins Fukuchi Caroline Yang Ying Ying Yang Jun Bo Yang Zhi Yun Hu Yi Ma Hong Soltis Pamela S Soltis Douglas E Li De Zhu Smith Stephen A Yi Ting Shuang et al 2021 Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms Nature Plants 7 8 1015 1025 bioRxiv 10 1101 2021 03 13 435279 doi 10 1038 s41477 021 00964 4 PMID 34282286 S2CID 232282918 Stull Gregory W et al 2021 main dated supermatrix tree T9 tre Figshare doi 10 6084 m9 figshare 14547354 v1 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help External links edit nbsp Media related to Amentotaxus at Wikimedia Commons nbsp Data related to Amentotaxus at Wikispecies Gymnosperm Database Flora of China Retrieved from https en wikipedia org w index php title Amentotaxus amp oldid 1206239768, wikipedia, wiki, book, books, library,
