Department of Plant Biology, 228 Plant Science, Cornell University, Ithaca, New York 14853 USA.
Am J Bot. 2003 Nov;90(11):1567-84. doi: 10.3732/ajb.90.11.1567.
A developmental series of flowers and fruits of Quercus acutissima (subgenus Quercus section Cerris) was collected over a growing season and examined for an intersectional, comparative anatomical study. Pistillate flowers of the current growing season, each consisting of a pistil with three long, slightly recurved styles, six tepals, and an inconspicuous ovary subtended by a few cycles of cupule scales, emerged in early May, were pollinated by mid-May, and then were quiescent for the remainder of the growing season. Flowers from the previous growing season resumed growth in mid-May, each forming three locules delimited by septa in the ovary, with two bitegmic, epitropous ovules developing in each locule. Mature embryo sacs were present by mid-July of the second growing season, although embryos were not observed until early August. Fruit maturation was complete by late September. Features that have not been described previously for the section Cerris include early-lignifying endocarp trichomes, persistent septa, and leaf primordia buttresses on the embryo. A comparison of flower and fruit developmental features with sections Quercus sensu stricto and Lobatae revealed a mosaic of shared features among the three sections.
采集了一个生长季节的麻栎（分为麻栎属和栓皮栎属）的花和果实的发育系列，并进行了交界面比较解剖学研究。当前生长季节的雌性花朵，每个花朵由一个具有三个长而略微弯曲的花柱、六个花被片和一个不显眼的子房组成，子房由几圈杯状鳞片支撑，于 5 月初出现，5 月中旬授粉，然后在整个生长季节处于休眠状态。上一季的花朵于 5 月中旬恢复生长，每个花朵在子房内形成三个由隔膜分隔的腔室，每个腔室中有两个双珠被、背生的胚珠发育。成熟的胚囊于第二年生长季节的 7 月中旬出现，尽管直到 8 月初才观察到胚胎。果实成熟于 9 月底完成。栓皮栎属中以前未描述过的特征包括早木质化的内果皮毛、持久的隔膜和胚上的叶原基支柱。与狭义的栎属和山毛榉属相比，花和果实发育特征的比较揭示了这三个属之间存在共享特征的马赛克。
