%0 Journal Article %A CHEN Xiang-Bo %A LÜ Xiu-Li %A LIU Yang %A ZHAO Ming-Shui %A CUI Xin-Hong %A ZHANG Dong-Mei %T Floral Morphology and Flowering Process of Acer yangjuechi, the Extremely Endangered Plant %D 2019 %R 10.7525/j.issn.1673-5102.2019.03.002 %J Bulletin of Botanical Research %P 329-337 %V 39 %N 3 %X To reveal the reproduction mechanism of low embryo development rate, the floral morphology and flowering process of Acer yangjuechi Fang et P.L.Chiu, the extremely endangered plants in Chinawas determined by testing trees cultivated in National Nature Reserve of Tianmu Mountain, Zhejiang Province.The results show that:(1)Bisexual flowers and maleflowers are inserted on a same apical inflorescence, and the bisexual flowers are always on the top of rachis while maleflowers on lateral rachis top or bottom. The quantity ratio of maleflowers to bisexual flowers is 6.89 of 2.6 times exceeding to A.buergerianum, which indicates less bisexual flowers of A.yangjuechi than A.buergerianum. (2)Two type of maleflowers were observed. Type â… maleflowers have tiny ovary, the stigma shortened extremely to a black spot and with flat flower disc while Type â…¡maleflowers have biforked stigma outstanding upon ovary degenerated into white fluff and with thick and radial sunken flower disc. Bisexual flowers possess of outstanding oblate spheroid and shorter filament compared with maleflowers. (3)The flowering process of individual tree is of bisexual flowers flowering within 3 days previous to maleflowers while only under seven percent of maleflowers were on pollination stage at the same time. (4)For population flowering process, the flowering stage between bisexual flowers and maleflowers present an obvious interval and bisexual flowers flowering intensively previous to maleflowers. Therefore, the main cause of the high embryo abortion, which leads to endangered situation of A.yangjuechi, was discussed. %U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2019.03.002