夏日里四种家居软装风格布局

1、第五章第五章 植物器官的结构及组织分化植物器官的结构及组织分化四、花四、花 Flower酒店设计 http:/The duckweeds (family Lemnaceae) arethe smallest flowering plants; their struc-tural features mark them as extremelyreduced relatives of the aroid family(Araceae), the family that includes callalilies (Zantedeschia) and Philodendron.(a) A honeyb

2、ee resting on a dense float-ing mat of three species of duckweed. Thelarger plants are Lemna gibba, about 2to 3 millimeters long; the smaller onesare two species of Wolffia, up to 1 milli-meter long. (b) A flowering plant of W.borealis, with a circular concave stigma(looking like a tiny doughnut) an

3、d a min-ute anther just above it, both protrudingfrom a central cavity. The whole plantis less than 1 millimeter long. (c) Flower-ing plant of L. gibba; two stamens anda style protrude from a pocket on theupper surface of the plant.Monocots. (a) A member of the palmfamily, ily, the coconut palm (Coc

4、os nuci-fera), grozoing in Tehuantepec, Oaxaca, Mexicon. The fruit of coconut is a drupe, not a nut (see Chapter 19). (b) Flowersand fruits of the banana plant (Musa Xparadisiaca). The banana flower has an in-ferior ovary, and the tip of the fruit bears a large scar left by the fallen flower parts.(

5、c) Rice (Oryza sativa) is a member ofthe grass family.function of the leaves. (c) Round-lobedhepatica (Hepatica americana), whichflowers in deciduous woodlands in theearly spring. The flowers have no petalsbut have six to ten sepals and numerousspirally arranged stamens and carpels.(b) Saguaro cactu

6、s (Carnegiea gigantea).The cacti, of which there are about 2000species, are almost exclusively a NewWorld family. The thick, fleshy stems,which store water, contain chloroplastsand have taken over the photosynthetic穗状花序伞形花序伞房花序总状花序圆锥花序柔荑花序复伞形花序头状花序肉穗花序（一）花的组成与基本结构（一）花的组成与基本结构花花花柄花柄 Pedicel花托花托 Recep

7、tacle花被花被 Perianth雄蕊群雄蕊群 Androecium雌蕊群雌蕊群 Gynoecium1、花柄和花托、花柄和花托下位花周位花上位花2、花被、花被花萼花萼 Calyx花冠花冠 Corolla萼片萼片：由薄壁组织、维管系统及表皮层组成：由薄壁组织、维管系统及表皮层组成Sepal 表皮层上有气孔和表皮毛表皮层上有气孔和表皮毛花瓣花瓣：由薄壁组织、维管系统及表皮层组成由薄壁组织、维管系统及表皮层组成Petal 表皮层细胞的垂周壁呈波纹状或内脊，表皮层细胞的垂周壁呈波纹状或内脊， 表皮层上有气孔和表皮毛表皮层上有气孔和表皮毛 薄壁组织中可含有一些异细胞，成熟薄壁组织中可含有一些异细胞，成

8、熟 花瓣中花瓣中 有有色体或细胞液中有花青素有有色体或细胞液中有花青素3、雄蕊群、雄蕊群花药花药 Anther花丝花丝 Filament4、雌蕊群、雌蕊群子房子房 Ovary花柱花柱 Style柱头柱头 Stigma基本单位是心皮基本单位是心皮 CarpelParts of a lily (Lilium henryi) flower.(a) An intact flower. In some flowers,such as lilies, the sepals and petals aresimilar to one another, and the perianthparts may the

9、n be referred to as tepals.Note that the sepals are attached to thereceptacle below the petals. (b) A partlydissected flower with two tepals and twostamens removed to reveal the ovary.The gynoecium consists of the ovary,style, and stigma. The stamen consists ofthe filament and anther. Note that thes

10、epals, petals, and stamens are attachedto the receptacle below the ovary, whichis made up, in the lily flower, of threefused carpels. Such a flower is said tobe hypogynous.The wall of the pollen grain serves toprotect the male gametophyte on its oftenlIozardous journey between the antherand the stig

11、ma. The outer layer, or exine,is composed chiefly of a substance knownossporopollenin, which appears to be apolymer composed chiefly of carotenoids.The exine, which is remarkably toughatld resistant, is often elaboratelyculptured. The sculpturing of pollen grain wallsis very precise and distinctly d

12、ifferentfrom one species to another, as revealedill these scanning electron micrographsof pollen grains. (a) Pollen grains of thehorse chestnut (Aesculus hippocasta-num). The pore of each grain throughwhich a pollen tube may emerge is vis-ible in the furrow. (b) Pollen grains ofa lily (Lilium longif

13、lorum). (c) Detailof the surface of a lily (L. longiflorum)pollen grain. (d) Pollen grain of thewestern ragweed (Ambrosia psilosta-chya). The pollen of ragweed is aprimary cause of hay fever. Spiny pollengrains such as these are common amongmembers of the sunflower family, Aste-raceae, of which ragw

14、eed is a member.Mature pollen grain of Lilium, contain-ing a two-celled male gametophyte. Thespindle-shaped generative cell will dividemitotically, giving rise to two sperm; thelarger tube cell, which contains the gen-erative cell, will form the pollen tube.The round structure above the generativece

15、ll is the tube cell nucleus, with itsred-stained nucleolus.Mature pollen grains-three-celledmale gametophytes of the telegraph plallt,Silphium (family Asteraceae). Prior topollination, each pollen grain containstwo filamentous sperm cells, which aresuspended in the cytoplasm of the largertube cell.

16、In other words, the pollen ofSilphium is shed at the three-celledstage, whereas that of Lilium, shownin the preceding figure, is shed at thetwo-celled stage.侧膜胎座中轴胎座特立中央胎座Lilium. Some stages in development ofall ovule and embryo sac. (a) Two youngovules, each with a single, large mega-sporocyte. Int

17、eguments have not begunto develop. (b) Ovule now has integu-ments. The megasporocyte is in the firstprophase of meiosis. (c) Ovule witheight-nucleate embryo sac (only six oftile nuclei can be seen here, two at thechalazal end and four at the micropylarend). The polar nuclei have not yetmigrated to the center of the sac.五、种子五、种子 Seed种皮种皮Seed coat胚胚embryo胚乳胚乳endosperm子叶子叶胚芽胚芽胚轴胚轴胚根胚根珠被珠被受精卵受精卵受精极核受精极核六、果实六