The Families and Genera of Vascular Plants 6 Flowering Plants. Dicotyledons Celastrales, Oxalidales, Rosales, Cornales, Ericales Bearbeitet von Klaus Kubitzki 1. Auflage 2004. Buch. xi, 489 S. Hardcover ISBN 978 3 540 06512 8 Format (B x L): 21 x 27,9 cm Gewicht: 1470 g Weitere Fachgebiete > Chemie, Biowissenschaften, Agrarwissenschaften > Botanik Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. 14 S. Dressler and C. Bayer Actinidiaceae S. Dressler and C. Bayer Actinidiaceae Gilg & Werderm. in Engler & Prantl, Nat. Vessels of the primary xylem are mostly solitary, Pflanzenfam., ed. 2, 21: 36 (1925), nom. cons. often large, and often arranged in radial rows. Saurauiaceae J. Agardh (1858). They can have annular, helical, reticulate, or scala- riform thickenings. Perforation plates are scalari- Trees, shrubs or climbers, with simple or variously form, more rarely simple. The pericycle includes a branched trichomes. Leaves alternate, simple, continuous ring of sclerenchyma. Young stems usually serr(ul)ate or dentate, pinnatinerved, peti- have a solid pith, which may later disintegrate olate; stipules absent or minute. Flowers in axillary and/or become lamellate in some Actinidia cymes or thyrso-paniculate inflorescences, some- species. The lamellae and a cylinder of outer pith times solitary, pedicellate, actinomorphic, herm- cells become sclerenchymatous with age. aphroditic or unisexual; sepals (3–)5(–8), The wood of Actinidia has dimorphic vessel ele- imbricate-quincuncial in bud, usually persistent; ments: few very large, moderately long vessel ele- petals (3–)5(–9), longer than sepals, distinct or ± ments with simple perforations, and numerous fused at base, imbricate in bud; stamens smaller, usually scattered or solitary, with oblique (10–)20–240, filaments distinct, sometimes adnate scalariform perforation plates. Saurauia has ex- to petals and falling with these, anthers dithecal, clusively solitary vessels with many-barred sca- dorsifixed, versatile, extrorsely dehiscent by longi- lariform perforation plates. Parenchyma is tudinal slits or subapical pores; ovary superior, diffuse apotracheal. Non-septate fibre tracheids syncarpous, (3–)5- to many-locular, sometimes have numerous bordered pits. Rays are uniseriate incompletely septate, pubescent or glabrous, and multiseriate, heterogeneous (Lechner 1914; sometimes with apical depression; placentation Metcalfe and Chalk 1950). axile, placentae sometimes split; ovules numerous, Wang et al. (1994) studied the root anatomy of anatropous, unitegmic; stylodia distinct, as many five Actinidia species; cortex and endodermis as locules, sometimes persistent, or style simple, persist during secondary thickening. stigma sometimes capitate; fruit usually a berry, sometimes dehiscent; seeds numerous, exarillate, Reproductive Structures.Cauliflory is enclosed by pulp, albuminous, embryo large, reported for some species. Saurauia callithrix is usually straight. special by having leafless inflorescences at the base A family of c. 360 spp. in three genera native to of the trunk which spread in the soil and leaf litter, tropical Asia and America, a few spp. of Actinidia elevating the flowers just above the forest floor in temperate E Asia. (Gilg and Werdermann 1925). The flowers are often arranged in cymes, which are subtended by Vegetative Anatomy.Young organs are foliage leaves or bracts. Some Saurauia have axil- covered with simple or multicellular, sometimes lary thyrso-paniculate inflorescences that include glandular hairs, which can be of diagnostic value monochasia. Bracteose prophylls are frequently (see Hunter 1966). Raphides contained in elon- found. gated idioblasts occur in most tissues.Crystal sand The flowers are mostly pentamerous but a few is reported for Clematoclethra (Lechner 1914). Saurauia and Actinidia species have tetramerous The leaves are dorsiventral and sometimes have flowers, and other exceptions occur also. In pen- an arm palisade mesophyll. Some species form a tamerous flowers, quincuncial aestivation of multilayered hypodermis.Stomata of the ranuncu- sepals is evident even in open flowers, since the laceous type are restricted to the abaxial side abaxial face is often pubescent in the two outer- (Lechner 1914; Metcalfe and Chalk 1950).Venation most sepals, half pubescent in one other, and is pinnate and of the camptodromous type. The glabrous in the two innermost sepals. For ultimate marginal veins are looped, but some anatomical features see Dickison (1972) and branches extend into the teeth (Yu and Chen 1991). Schmid (1978a). Actinidiaceae 15 Petals and stamens may be fused to various (Erdtman 1952; Dickison et al. 1982; Zhang 1987; degrees and often fall together. The microsporan- Li et al. 1989; Kang et al. 1993). Similar pollen gia of each theca merge. Pollen is released through occurs in Theaceae, Ochnaceae and Clethraceae longitudinal slits or pores that become extrorse by (Erdtman 1952; Zhang 1987), but there are some inversion of the anthers. differences to Dilleniaceae (Dickison et al. 1982). Brown (1935) reported nectar-secreting tissue at Functionally female flowers of Actinidia deli- the base of the petals of Saurauia subspinosa. ciosa shed nonviable pollen, which is usually enu- According to his study, the androecium is basically cleate and shrivelled but otherwise similar to diplostemonous. The outer whorl is formed by viable pollen (Schmid 1978a; White 1990). single stamens in front of the sepals, whereas the majority of stamens develop in centrifugal succes- Karyology.Chromosome counts are known for sion by splitting of antepetalous primordia. For many Actinidia species (see Yan et al. 1997). The Actinidia deliciosa,Brundell (1975) described two basic chromosome number is x = 29; diploids, or three whorls of staminal initials, depending tetraploids, hexaploids and octoploids occur. on the cultivar. In a more detailed study of A. Intraspecific variation appears to be common melanandra and A. deliciosa,van Heel (1987) (mainly diploid and tetraploid cytotypes, 4¥ and found a single whorl of staminal primordia in the 6¥ in A. valvata,and 4¥,6¥ and 8¥ in A. arguta). former, and centrifugal multiplication of such For Saurauia,counts of n = 30 (South American primary primordia in the latter. The numerous species: Soejarto 1969, 1970) and n = 20 (Asian carpel primordia arise in a single whorl. species: Mehra 1976) were reported. Embryology.The anther wall consists of epider- Reproductive Biology. Actinidia is usually mis, fibrous endothecium, 2–3 ephemeral middle dioecious, Clematoclethra and Saurauia have layers, and a secretory tapetum of multinucleate mostly bisexual flowers. American Saurauia, cells the nuclei of which may fuse and become however, is described as functionally dioecious polyploid. Raphides are present in the anther wall with dimorphic flowers: long-styled, functionally and connective. Meiotic division of microspore female flowers with malformed, sterile pollen, and mother cells is simultaneous. Pollen is shed at the short-styled ones with fertile pollen (Soejarto two-celled stage. 1969). Brown (1935) reported protandry. The ovules are anatropous, unitegmic and tenu- In Actinidia deliciosa,staminate flowers open inucellar. A hypostase is present. The nucellus is about seven days before pistillate ones. Plants of thin and ephemeral. A hypodermal archesporial the pistillate cultivar ‘Hayward’ in New Zealand cell forms the chalazal megaspore mother cell bloom 10–18 days, staminate clones usually flower which develops into a linear tetrad. Embryo sac 3–5 days longer (Hopping 1990). Because of this development is of the Polygonum type (Vija- limited overlap in flowering and the linear rela- yaraghavan 1965; An et al. 1983). Inverted embryo tionship between seed number and fruit weight, sac polarity is reported of Saurauia nepalensis fruit set is improved by artificial pollination. (Rao 1953). Endosperm formation is cellular; Pollen tubes from the distinct stylar branches are embryogeny corresponds to the Solanad type evenly distributed to the numerous carpels and (Crété 1944b; Vijayaraghavan 1965). Polyembry- ovules by a compitum (“pollen tube distributor ony due to the proliferation of suspensor cells was cup”: Howpage et al. 1998). For pollen–pistil inter- observed in Actinidia deliciosa (Crété 1944a). action, pollen tube growth and fertilisation of Actinidia,see Hopping and Jerram (1979), Harvey Pollen Morphology.Pollen of Actinidiaceae is et al. (1987) and González et al. (1996). remarkably uniform and rather unspecialised. Actinidia deliciosa is said to be bee- or wind- Pollen is usually shed in monads; Saurauia elegans pollinated. Despite the abundance of literature has tetrads. The grains are usually 3(4)-colporate, on the floral biology of cultivated kiwifruit (e.g. oblate-spheroidal to prolate, the longest axis Schmid 1978a; Harvey et al. 1987; Harvey and 13–26(–33) mm. The colpi are long, crassimar- Fraser 1988; Hopping 1990; Howpage et al. 1998), ginate and usually exhibit an equatorial bridge of there is only little information on pollination in ektexine over the endoaperture. Exine is (1–)1.5–2 the wild. Gilg and Werdermann (1925) suspect mm thick. Sexine is as