The floral nectaries in theLimnanthaceae

Floral nectaries in theLimnanthaceae are established as exoscopic basal bulges of the episepalous stamens. Their nectariferous tissues include the epidermis and hypodermal parenchyma and inLimnanthes are vascularized by phloematic branches of the staminal bundles. Secretion occurs mainly through anomocytic stomata but, in addition, probably through the outer cuticularized thin walls of the epidermal cells. The flower structure is comparatively simple. The nectar is often slightly concealed. A wide range of pollinators can be expected, but bees are observed to be the dominant ones. The systematic position of the family is still obscure. Taxonomic placement near to any other geranialian families or to theCaryophyllaceae is only weakly justified.The floral nectaries of theGeraniales and their systematic implications II. For the first part seeLink (1992).     

Pollination biology ofOpuntia polyacantha andOpuntia phaeacantha (Cactaceae) in southern Colorado

The phenology, compatibility system, and pollinator fauna ofOpuntia polyacantha Haw. andO. phaeacantha Engelm. in southern Colorado were studied and compared. The total blooming periods overlap, but the peak of blooming differs between the species withO. polyacantha blooming first and for longer. Neither species is apomictic,O. polyacantha is largely self-incompatible andO. phaeacantha is self-compatible but may not automatically fully self-pollinate. Examination of flowering structures showed that the former has larger flowers with more perianth parts and heavier (but fewer) anthers. Further the flowers of the allogamous species are visited by greater diversity (but similar abundance) of pollinators. Medium to large bees of the generaDiadasia, Lithurge, Melissodes, Bombus, Agapostemon andMegachile were found to be effective pollinators of the Opuntias studied. The two species were compared as to their floral attributes, breeding systems, and pollinators, and the possible role of competition for pollinators is discussed with respect to its role in their evolutionary paths.     

Die Stipeln derIrvingioideae undRecchioideae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie

TheSimaroubaceae generally have no true stipules. The stipule-like appendages of some genera proved to be pseudo- or metastipules (Weberling & Leenhouts 1965). There seem to be some exceptions, however: the generaCadellia (incl.Guilfoylia) andRecchia on the one hand, and theIrvingioideae on the other. As these taxa, with exception ofRecchia, have simple leaves, there are no indications that their stipule-like appendages might be pseudo- or metastipules. In regard to their position and ontogeny these appendages behave completely like true stipules. Assuming the view ofForman, one could conceive a morphological line from the long, broadly inserted axillary stipules of mostIrvingioideae to the small scaly triangular stipules ofIxonanthoideae. The similarities between the stipules ofIrvingioideae andErythroxylaceae (already emphasized byHallier and others), become even more evident when their ontogeny is investigated. TheIrvingioideae, therefore, might be regarded as a separate family (perhaps with some relation to theErythroxylaceae,Hallier) or as a subfamily ofIxonanthaceae (Forman).—In addition to data on stipules some results on the palynology and shoot anatomy of the generaCadellia (incl.Guilfoylia) andRecchia are reported. Their relationship with theSimaroubaceae also appears doubtful. If they are to be included, they represent a somewhat isolated group near the base of the family which otherwise has lost its stipules.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Nectar by day and night:Siphocampylus sulfureus (Lobeliaceae) pollinated by hummingbirds and bats

Most species of the neotropical genusSiphocampylus are believed to be bird-pollinated. The pollination biology ofSiphocampylus sulfureus was studied in a montane region in SE Brazil. This species has features intermediate between ornithophilous and chiropterophilous syndromes: it presents a striking combination of yellowish flowers with strong odour (chiropterophilous features), and diurnal anthesis and sucrose-dominated nectar (ornithophilous features). Major pollinators were hummingbirds by day, and a phyllostomid bat by night.Siphocampylus sulfureus may be viewed as a recent derivate from the presumed ornithophilous stock within sect.Macrosiphon, and thus benefits from the activity of both diurnal and nocturnal vertebrate pollinators.Dedicated to DrIlse Silberbauer-Gottsberger and Prof. DrGerhard Gottsberger for their pioneer contribution to floral biology in Brazil.     

Heliantheae sensu lato (Asteraceae), clades and classification

The interrelationships within theHeliantheae s. lato and the closely relatedEupatorieae are analyzed and discussed. The basis to this discussion is a cladistic analysis of 141 morphological characters (172 apomorphic states) scored for 97 genera. TheHeleniae s. lato, a subgroup of theHeliantheae s. lato, are paraphyletic, and a monophyletic group corresponding largely to theHeliantheae s. str. is recognized. TheEcliptinae sensuRobinson are polyphyletic. TheCoreopsidinae form an ingroup in theHeliantheae s. str. TheTageteae (Pectidinae) and theMadieae (Madiinae) are two separate branches within the helenioid assemblage of taxa.     

Randmusterbildung und Synorganisation bei strahlenden Apiaceendolden

Radiant umbels result from the enlargement of peripheral phyllomes. We find the following patterns: 1) TheOrlaya-type: only one petal in the flower is enlarged. 2) TheCoriandrum-type: one whole and two half petals in the flower are enlarged. 3) TheArtedia-type: two half petals in the flower are enlarged. 4) TheXanthosia-type: the enlargement affects three involucellar bracts of which two become asymmetrical.—The enlargement of the phyllomes can effect the umbellet or the umbel or both. Obviously, this is the reason why many of these inflorescence systems display insufficient degrees of synorganization, with an optimum reached inArtedia and some species ofXanthosia.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Pollination-related characteristics in the mimosoid legumeAcacia terminalis (Leguminosae)

Intraspecific variation has been found for several pollination-related characteristics in two isolated populations of the self-incompatible treeAcacia terminalis: floral characteristics including colour and flowering time; style length; size and colour of extrafloral nectaries on the leaf petioles; chemical components of the extrafloral nectar; different taxa of bee pollinators; and frequency differences in bird pollinators. These differences possibly reflect the evolution of two different pollination syndromes within this species.     

A taxonomical revision ofThymus sect.Teucrioides (Lamiaceae)

TheThymus teucrioides Boiss. & Spruner aggregate is revised and the following new taxa, all from the alpine zone in the Greek mountains, are described:Th. leucospermus Hartvig from the calcareous mountains of Pindhos and Mt Parnassos in Sterea Ellas,Th. rechingeri Hartvig with the subsp.macrocalyx Hartvig from calcareous mountains in Sterea Ellas and N Peloponnissos, andTh. teucrioides subsp.alpinus Hartvig from the serpentine areas of N Pindhos. In the variableTh. teucrioides s. str. many characters have turned out to be markedly geographically correlated and many local populations can be distinguished by a particular combination of characters.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

Phylogenetic analysis ofUlmaceae

A phylogenetic analysis of theUlmaceae, Cannabaceae, Barbeyaceae, andBroussonetia of theMoraceae produced nine equally parsimonious trees with 127 steps. TheUlmoideae (Ulmaceae, sensuGrudzinskaya) are a monophyletic group and distinct from theCeltidoideae. The genusAmpelocera occupies an isolated taxonomic position among the celtidoids. The similarity ofAmpelocera to the fossil celtidoid flowerEoceltis of North America suggests thatAmpelocera posesses an archaic suite of characters, and occupies a primitive position among the celtidoids, theCannabaceae and theMoraceae. The relationships among the other celtidoid taxa,Cannabaceae, andBroussonetia are problematic. TheCannabaceae andBroussonetia of theMoraceae are nested within the celtidoids suggesting that this is a paraphyletic group. The close, but unresolved, relationship of the celtidoids to theMoraceae andCannabaceae observed in this analysis, and the appearance of the celtidoids in the fossil record prior to the ulmoids suggests that the evolutionary relationship of the ulmoids and celtidoids may be more distant than current taxonomic treatments reflect.     

The genusIschnea (Asteraceae,Senecioneae) in New Guinea

The endemic New Guinean genusIschnea F. Muell. (Asteraceae, Senecioneae, Blennospermatinae) is revised and four species are recognized. Characters of special interest are tubeless ray florets, male disc florets, and secretory spaces in leaves. A principal component analysis is made on theIschnea elachoglossa F. Muell. complex which shows great variation. One new species,I. capellana Swenson, from the Star Mountains, is described. A key, illustrations, and distribution maps to all species are supplied.     

Ribosomal RNA sequence comparisons demonstrate an evolutionary relationship betweenZygnematales and charophytes

The nuclear-encoded small subunit ribosomal RNA (rRNA) sequences were determined forGenicularia spirotaenia, Mesotaenium caldariorum, andStaurastrum spec. (Zygnematales) to elucidate the evolutionary position of these green algae. Results of neighbour-joining and maximum parsimony phylogenetic analyses support a monophyletic origin of theZygnematales within the evolutionary assemblage defined by theCharophyceae (sensuMattox & Stewart) and land plants. TheZygnematales/Charophyceae/land plants are evolutionarily distinct from the monophyletic lineage defined by theChlorodendrales, Pseudoscourfieldiales, and theMicrothamniales/Chlorophyceae. In memoriamRobert W. Hoshaw.     

Floral rewards in someScrophularia species (Scrophulariaceae) from the Iberian Peninsula and the Balearic Islands

The genusScrophularia in the Iberian Peninsula and Balearic Islands comprises two sections,Scrophularia andCanina G. Don. Analyses were carried out on flower production, flower duration and their sexual phases, pollen and nectar production together with observations on their pollinators. Nectar production is correlated with corolla size and pollen production with anther size. The taxa of sect.Scrophularia show greater nectar and pollen production than those of sect.Canina. Also, those of the first section produce more ovules per ovary than those of the second group, production being correlated with the ovary size.Some observations on floral and reproductive biology in some species ofScrophularia from the Iberian Peninsula and the Balearic Islands. I.     

Omphalotaceae fam. nov. undPaxillaceae,ein chemotaxonomischer Vergleich zweier Pilzfamilien derBoletales

TheOmphalotaceae fam. nov., which include the generaOmphalotus andLampteromyces, are defined on the basis of characteristic sesquiterpenes and of their ability to cause white-rot. Anatomical and morphological features of the representatives of these genera support the creation of this new family. The occurrence of pigments, typical of theBoletales, and of cyanophilous spores, indicate membership of theOmphalotaceae in the orderBoletales. Relationships to the other families of this order — especially to thePaxillaceae — are discussed. The possible functional significance of fungal metabolites is considered.

Herrn Prof. Dr.J. Poelt zur Vollendung seines 60. Lebensjahres gewidmet.—Veränderte Fassung eines Vortrages auf der Tagung der Deutschen Botanischen Gesellschaft, Wien, September 1984.     

Chloroplastrps16 intron phylogeny of the tribeSileneae (Caryophyllaceae)

Intron sequences of the chloroplast generps16 from 46 species were used to examine phylogenetic relationships indicated by nrDNA ITS sequence variation in the tribeSileneae (Caryophyllaceae, Caryophylloideae). This region has previously not been utilized for phylogenetic purposes but the results presented here suggest that it is a consistent and valuable complement to the ITS sequences. Therps16 intron trees are largely congruent with the ITS trees. All the major hypotheses suggested by the ITS data are supported, often at similar bootstrap levels. The joint usage ofrps16 intron and ITS sequences provides a powerful tool for resolving many of the difficult taxonomic issues in the tribeSileneae. Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Some problems of forest transformation at the transition to the oligocratic/<Emphasis Type="Italic">Homo sapiens</Emphasis> phase of the Holocene interglacial in northern lowlands of central Europe

The paper discusses the main changes in the composition of mixed deciduous forests which occurred mostly between 5,000 and 2,000 b.p., based on selected pollen diagrams from the lowlands of Germany, Denmark and Poland, and including two pollen diagrams from varved sediments, used as reference sites, and on isopollen maps for Poland. The Ulmus retreat is shown on maps, and additional data for its pathogenic origin are presented. Corylus declines at ca. 3,500 b.p. at both reference sites, and its connection with Fagus expansion in the west and Carpinus expansion in the east is discussed. The nature of post-Atlantic transitory shrub–forest communities with dominant Corylus and Quercus is presented. Relationships between the history of Fagus and Carpinus and the development of human settlements are shown. Human impact has been admitted as one of the most important driving forces determining vegetational development since the time of fully developed Neolithic cultures. Other very important abiotic factors were the climate (particularly after 2,500 b.p.), and soil degradation.     

Systematic relationships of theSaxifragales revealed by serological characteristics of seed proteins

Comparative investigations of serological characters of seed proteins from taxa regarded as members of theSaxifragales result in the recognition of two distinct groups of related families. One consists of theSaxifragaceae, Grossulariaceae, andCrassulaceae; to itHamamelis, and possiblyPenthorum and theRosaceae may be connected. The second group contains theHydrangeaceae, Escalloniaceae, Roridulaceae, Cornaceae, andCaprifoliaceae; it is rich in iridoid compounds, has more derived morphological characters, and seems to represent a monophyletic line block. ThePittosporaceae were not found to be linked with either of the two groups, but rather show similarities with members of theApiales. All these data support systematic arrangements proposed byDahlgren (1975a).     

Pollination ofOpuntia lindheimeri and related species

The large, yellow, bowl-shaped flowers ofOpuntia lindheimeri, O. discata, O. phaeacantha major, andO. compressa in Texas are visited by various species of beetles and bees. The beetles and small bees (Perdita, Dialictus) are pollen thieves. The pollinators are the medium-sized and larger bees (Melissodes, Diadasia, Lithurge, Megachile, Agapostemon, etc.). Different species of theOpuntia lindheimeri group have the same pollination system and there is no evidence of any floral isolation between them. The pollination system of these species ofOpuntia in Texas is essentially the same as that ofEchinocereus fasciculatus andFerocactus wislizeni in Arizona.Pollination of North American Cacti, II.—SeeGrant & Grant (1979).     

Comparative ultrastructure of pyrenoids inTrebouxia (Microthamniales,Chlorophyta)

Pyrenoid ultrastructure has been investigated from cultures of all 26 species ofTrebouxia with the aim of establishing pyrenoids as a taxonomic character. Different arrangements and forms of thylakoid lamellae within the pyrenoid matrix allow eight pyrenoid types to be distinguished. Each type is characteristic of a group of species. Thegigantea- andimpressa-type are similar, differing only in the form of the tubules: short, branched tubules mark thegigantea-type; ± long and straight invaginations theimpressa-type. Thearboricola-type is characterized by meandering pyrenoid membranes developing from lamellae parallel with each other in young autospores. Pyrenoids of thegelatinosa-type are traversed by thin parallel-arranged tubules. Few thylakoids with a curved profile are typical of theirregularis-type. Thecorticola-type is different from all others in having a distinct starch sheath closely connected with the pyrenoid matrix and no pyrenoglobuli being associated with the pyrenoid membranes. No true pyrenoids have been found inT. magna andT. erici. Within the chloroplast, they have indistinct areas with pyrenoglobuli, but without differentiated thylakoids. Pyrenoid morphology is stable in culture on different media as well as in phycobionts within lichen thalli. Comparing the pyrenoid of a lichenizedTrebouxia with that from cultured species, the identification of the phycobiont within the lichen thallus is possible, without the need of culturing the algae. This has been shown in species ofParmelia andHypogymnia. New aspects for the taxonomy and systematics ofTrebouxia are discussed.Dedicated to Prof. DrLothar Geitler on the occasion of the 90th anniversary of his birthday.     

Flowering, pollination, nectar standing crop, and nectaries ofEuterpe precatoria (Arecaceae), an Amazonian rain forest palm

Flowering and pollination biology of the monoecious palmEuterpe precatoria was studied in the forest of the Reserva Ducke near Manaus, Brazil, during two annual flowering periods (middle of October to end of March) between 1991 and 1993. Individuals produced one to four bisexual inflorescences per flowering period. Inflorescences have staminate and pistillate flowers in triads. The anthesis of the whole inflorescence averaged 26 days, with the male phase extending over the first 17 days, followed by six days without any open flowers, and the female phase covering the last three days. The distinct dichogamy of the inflorescence results in obligate outcrossing. The pollen-ovule ratio is high (42000). Both male and female flowers emit an almond oil-like scent and produce nectar in septal nectaries. The concentration and total amount of sugar of the nectar of female flowers (37% and 0.021 mg) were significantly higher than that of male flowers (9% and 0.007 mg). The nectar is hexose-rich and with a moderately high amino acid concentration (68 µg/ml).Euterpe precatoria seems to be a generally entomophilous palm with a predominance of beetles and bees as potential pollinators. The most constant visitors were beetles of the familiesCurculionidae, Chrysomelidae, Staphylinidae, and bees of the familyHalictidae. The actual composition of the insect spectrum depends on climatic and biotic factors. Additionally, wind pollination may occur. Fruit development lasted four months and ripe fruits are swallowed by toucans who thus disperse the seeds.This study is part of an unpublished doctoral thesis of the first author. The paper is dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer at the occasion of his 70th birthday