摘要:

AbstractThe five inflorescence types occurring in the Malayan species ofPhyllagathis(which cover essentially the spectrum of the whole genus) are demonstrated to represent modifications and derivations of a monotelic (determinate), hom(oe)ocladic thyrse. The elongate, spike‐like thyrse (usually referred to as ‘panicle’ in the taxonomic literature) as found inP. griffiihii, P. stoloniferaandP. cordataappears to be the most primitive type, from which – obviously independently – the ‘umbels’ ofP. hispidaandP. scortechiniihave envolved. In the ‘umbel’ of the latter the central flowers (including the terminal flower) regularly fail to develop (truncation, polytelic organization!). The meristematic apex often extends to an oval or band‐like structure; this may divide into two or three portions and give rise to acrogeneous branching. Quite different ‘umbel’ types are found inP. tuberculata, P. magnifica(both with ‘compound umbels’ = globose or hemisphaerical thyrses with long‐pedunculate cymes) andP. stonei(‘simple umbel’ achieved by complete reduction of the cyme peduncles). In the ‘heads’ ofP. rotundifoliaandP. praetermissaa distinct involucrum is developed by the enlargement of the cyme bracts. The thyrses ofAnerincleistus fruticosusare mostly reduced to fewflowered aggregates or solitary flowers. With regard to position, the epipetiolar displacement of the inflorescences onto a ‘phyllophore’ (P. cordata, P

ISSN:0014-8962    

DOI:10.1002/fedr.19961060512

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractInPittosporum tobiraall floral organs are initiated in a strictly acropetal succession. It is striking that sepals and petals show an extremely early hyponastical development. Important floral characters for placing the family Pittosporaceae near the Apiales (Araliaceae and Apiaceae) are the early sympetaly, only gradual differences in the gynoecium development and placentation, and the fact that a nectar secreting area is situated at the base of the dorsal carpel flanks (ovary superior in Pittosporaceae, inferior in Apiales).Viscid latex, which plays an important role in the dispersal of the seeds by exozoochory, is produced by the multicellular epidermal hairs in the septal (placental) region.

ISSN:0014-8962    

DOI:10.1002/fedr.19961060513

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractGeophytes require a special depth in the soil, and therefore, seedlings of many plant species move downward very soon after germination. In this paper, a comparison is made using two examples, the monocotyledonousLapeirousia laxaand the dicotyledonousFoeniculum vulgare.Using time lapse photography, functional differences become clear, characterised by typical seedling morphology.During germination ofFoeniculum vulgare, the hypocotyl elongates, which later has to be compensated by root and hypocotyl contraction in order to give the perennation buds a lower position for sprouting in the following year. InLapeirousia laxathe primary internodes remain short, and form the perennation organ (a corm), with their perennation buds protected by soil from the outset. Downward movement of the corm occurs by the contractile roots which develop successively at the corm. At the end of the first vegetation period, the corms ofLapeirousia laxaare in a 60–100 mm deeper position. In contrast,Foeniculum vulgaredevelops a turnip as its perennation organ, which, through self‐contraction causes the perennation zone to become lower. At the end of movement, the perennation buds are approximately 15–25 mm below the soil surface, while the total movement of the buds is measured to be 30

ISSN:0014-8962    

DOI:10.1002/fedr.19961060514

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0014-8962    

DOI:10.1002/fedr.19961060515

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractCyanastrumentwickelt aus einem chorikarpen Gynaezeum Teilfrüchte, die einsamigen, saftarmen Beeren entsprechen und sich durch einen Längsriß entlang des Dorsalmedianus öffnen. Die exo‐mesotestale Samenschale besteht aus lebenden Zellen, Endosperm ist nicht vorhanden. Der Embryo besteht aus einem voluminösen Speichercotyledo mit der in der kleinen Cotyledonarscheide eingeschlossenen Plumula. Hypocotyl und Primärwurzel fehlen. Die Keimpflanze entwickelt aus dem Epicotyl und den aufwärts folgenden Internodien die erste Sproßknolle. Die Foliation beginnt mit vier Niederblättern, denen das erste Laubblatt folgt.Das Keimblatt der Tecophilaeaceen hat im Ober‐blattbereich rein haustoriale Funktion, während das Unterblatt auf einer kurzen Scheidenröhre eine niedrige (Walleria) oder verlängerte (Cyanella) Coleoptile trägt. BeiCyanellafolgen auf den Cotyledo direkt linealische Primärblätter, beiWalleriawerden zunächst einige Niederblätter entwickelt.Eriospermumbesitzt einen langen, unifacialen, as‐similierenden Cotyledo vomAllium‐Typ mit winziger Cotyledonarscheide.Der Bau der Keimpflanzen spricht für die Selbständigkeit der Eriospermaceae und Cyanastraceae, währendWalleriain den Rahm

ISSN:0014-8962    

DOI:10.1002/fedr.19961060516

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0014-8962    

DOI:10.1002/fedr.19961060517

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractDue to the small size of the flower even basic information about the floral diagram in some genera of Eriocaulaceae is lacking. In this study it is shown, that the anthers ofLachnocaulonare not monothecate‐bisporangiate by lateral reduction as assumed in the past but bithecat‐bisporangiate by facial reduction. This is in contrast to the findings inToninaandPhilodice(STÜTZEL 1985), where occasional and irregular lateral reductions may occur. The dehiscence mechanism of the anthers ofLachnocaulonis very uncommon in opening the sporangia of both thecae with a single longitudinal slit. No rudiments of petals can be found inLachnocaulonduring the whole morphogenesis of male and female flowers.Species ofSyngonanthuswithout gynoecial nectaries do not have the stigmas in carinal position but in commissural position as it is typical for the genus. There is no argument to regard species ofSyngonanthuswithout gynoecial glands as a link toEriocaulon, which lacks also gynoecial nectaries but has the stigmas in carinal posi

ISSN:0014-8962    

DOI:10.1002/fedr.19961060518

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractIn einem vor allem für Lehr‐ und Lernzwecke gedachten Schema wird in zweidimensionaler tabellarischer Form ein Überblick über die strukturellen Möglichkeiten der Angiospermen gegeben, generative Diasporen zu bilden. Berücksichtigt werden die Merkmale Gynoeceumstyp/Diasporentyp/Perikarpanatomie. Dabei sind die Diasporen (mit Spring‐/Streu‐ und Schließfrüchten) gegen die morphologischen Gestaltungsmöglichkeiten des Gynoeceums (chori‐/coenokarp und ober‐/unterständig) aufgetragen. Die Tabelle zeigt, wie die Angiospermen in der Lage sind, aus unterschiedlichen Teilen des Gynoeceums und der Blüte sowie Blütenständen gleiche Funktionstypen zu erzeugen. Nicht berücksichtigt werden die Ausbreitungsweisen, die in der tabellarischen Darstellungsweise den morphologischen Möglichkeiten in der dritten Dimension überlagert wären. Nur sehr wenige Gestaltungsmöglichkeiten

ISSN:0014-8962    

DOI:10.1002/fedr.19961060519

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0014-8962    

DOI:10.1002/fedr.19961060520

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe Central Amazonian Annonaceae speciesBocageopsis multifloraandOxandra euneurawere studied with respect to anthesis, flowering phenology, odor production, and visitation and pollination of the flowers by insects. Flowers of both species are protogynous and have diurnal anthesis. The sweetish flower odors attract thrips toBocageopsisflowers and staphylinid beetles and thrips toOxandraflowers. These insects apparently are not harmful to flower tissues; they crawl on the stamens and stigmas and seem to be efficient pollen vectors. The stamens ofBocageopsisandOxandra, which possess a prominent tongue‐shaped connective prolongation supposedly represent the archaic stamen form within the Annonaceae. It is speculated that the stamens of these species could maintain their original laminar form with tongue‐shaped prolongations because of the low selection pressure exerted by the non‐destructive thrips and staphylinid beetles. The strong influence of voracious beetles on flower structures in other neotropical Annonaceae is disc

ISSN:0014-8962    

DOI:10.1002/fedr.19961060521

出版商:Wiley‐VCH Verlag    

年代:1996

数据来源: WILEY