P-type sieve-element plastids present in members of the tribesTriplareae andCoccolobeae (Polygonaceae) renew the links between thePolygonales and theCaryophyllales

Form-Pfs sieve-element plastids were found inTriplaris, Ruprechtia, andCoccoloba (Polygonaceae) while other genera of the family and those studied from the often associatedPlumbaginaceae contain S-type sieve-element plastids. The rareness of form-Pfs plastids among the angiosperms, their similarity to the peculiar form-P3fs plastids of theChenopodiineae, and the comparatively small plastid diameters measured for all forms present in theCaryophyllales, Polygonales, andPlumbaginales suggest close relationships between these taxa. The restriction inPolygonaceae of form-Pfs plastids to the closely allied tribesTriplareae andCoccolobeae is discussed with regard to both the intrafamilial and ordinal phylogeny, and also considering possible connections to the only magnoliidaean Pfs-taxonCanella. Dedicated to Univ.-Prof. DrF. Ehrendorfer on the occasion of his 70th birthday.     

Ultrastructure of sieve-element plastids inCaryophyllales (Centrospermae), evidence for the delimitation and classification of the order

The orderCaryophyllales (Centrospermae) was found to contain specific P-type sieve-element plastids which are characterized by protein inclusions composed of ring-shaped bundles of filaments and of central crystalloids. The sieve-element plastids of 14 families (140 species investigated) fit into this overall characterization, and more specific details are used to delimit the families and arrange them within the order.Phytolaccaceae, the basic family of the order display much diversity: the crystalloids inside their plastids are either globular (most genera) or polygonal (Stegnosperma), starch may also be present (Phytolacca).Nyctaginaceae, with starch inBougainvillea sieve-element plastids, can be derived directly fromPhytolacca. Globular crystalloids are present in most of the families, as inDidiereaceae, Cactaceae, Aizoaceae-Tetragoniaceae, Portulacaceae-Basellaceae-Halophytaceae-Hectorellaceae. Caryophyllaceae andLimeum ofMolluginaceae contain polygonal crystalloids (otherMolluginaceae with globular crystalloids). Crystalloids are entirely absent fromChenopodiaceae (incl.Dysphaniaceae) andAmaranthaceae. The probable relationships between these families are presented diagrammatically in Fig. 13. Bataceae, Gyrostemonaceae, Vivianiaceae, Theligonaceae, Polygonaceae, Plumbaginaceae, Fouquieriaceae, Frankeniaceae, andRhabdodendraceae—all at some time included into theCaryophyllales (Centrospermae) or doubtfully referred to them—develop S-type (or different P-type) sieve-element plastids. Their direct connection to theCaryophyllales therefore is excluded. Finally, evolutionary trends of theCaryophyllales are discussed.Presented in the Symposium Evolution of Centrospermous Families, during the XIIth International Botanical Congress, Leningrad, July 8, 1975.     

Further studies of the sieve-element plastids of theCaryophyllales includingBarbeuia,Corrigiola, Lyallia,Microtea, Sarcobatus,andTelephium

The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.     

Sieve-element plastids,exine sculpturing and the systematic affinities of theBuxaceae

The sieve-element plastids of members of several genera in theBuxaceae (Buxus, Pachysandra andSarcococca) were found to be of the specific subtype PVI, which contains a central globular protein crystal.Simmondsia (Simmondsiaceae) andDaphniphyllum (Daphniphyllaceae), on the other hand, were found to contain S-type sieve-element plastids. The occurrence of the highly restricted PVI plastids in theBuxaceae mitigates against a close relationship between theBuxaceae andSimmondsia, Daphniphyllum andEuphorbiaceae. Exine sculpturing of theBuxaceae andSimmondsiaceae also shows no close similarities. Both of these EM characters are discussed in connection with other available data and with respect to earlier systematic treatment of these families.     

P-type sieve-element plastids and the systematics of theArales (sensuCronquist 1988)—with S-type plastids inPistia

The sieve-element plastids of 126 species of theArales were investigated by transmission electron microscopy. With the exception ofPistia (with S-type plastids) all contained the monocotyledon specific subtype-P2 plastids characterized by cuneate protein crystals. While the species studied from bothAcoraceae andLemnaceae have form-P2c plastids (i.e., with cuneate crystals only), those of theAraceae belong to either form P2c (14 species), P2cs (the great majority) or P2cfs (Monstera deliciosa, only, with form-P2cs plastids in the otherMonstera species studied). The form-P2cs plastids of theAraceae are grouped into different categories according to the quantity and quality of their protein and starch contents. The subfamilyLasioideae is redefined to comprise all aroid P2c-taxa and those P2cs-genera that contain only one or very few starch grains. Only little starch is also recorded in the sieve-element plastids ofGymnostachys (Gymnostachydoideae), with the other plastid data denying a close relationship toAcorus. While equal amounts of starch and protein are generally present in sieve-element plastids of the subfamiliesPothoideae, Monsteroideae, Colocasioideae, Philodendroideae, andAroideae, maximum starch content and only very few protein crystals are found in form-P2cs plastids ofCalla (Calloideae),Ariopsis (Aroideae), andRemusatia (Colocasioideae?). In the latter, both morphology and size of sieve-element plastids are close to those ofPistia.—In theAraceae the diameters of the sieve-element plastids exhibit a great size range, but are consistent within a species and within a defined part of the plant body. Comparative data are mainly available for stem and petiole sieve-element plastids.—The accumulated data are used to suggest an affiliation of the species to subfamilies and to discuss the phylogeny of theArales. Forms and sizes of their plastids support a separation of bothAcoraceae andLemnaceae from theAraceae. The presence of S-type plastids inPistia does not favour direct and close relationships to the form-P2c genusLemna.—The prevailing form-P2cs plastids might support proposals that place theArales (together with also form-P2cs plastid containingDioscoreales) in the neighbourhood of basal dicotyledons. BesidesAsarum andSaruma (Aristolochiaceae), with monocotyledonous form-P2c plastids,Pistia (with dicotyledonous S-type plastids) gives another example for a link between the two angiosperm classes.     

Sieve-element plastids ofGymnospermae: Their ultrastructure in relation to systematics

The distribution of S-type and P-type plastids in the sieve elements of 30 species from 13 families of theConiferophytina andCycadophytina is recorded, of which 21 species were studied for the first time with respect to their sieve-element plastids. While starch storing S-type plastids are the most commonly occurring type throughout both taxa, all thePinaceae examined (11 species of 7 genera) contain P-type plastids characterized by a peripheral, ring-shaped bundle of protein filaments, an additional protein crystalloid, and several starch grains. Starch grains of sieve-element plastids in theConiferophytina andCycadophytina are commonly club-shaped. Taxonomic implications of these ultrastructural findings on sieve-element plastids are discussed.     

Classical morphological features of centrospermous families

The orderCentrospermae (Caryophyllales, Chenopodiales) as treated inA. Englers Syllabus, 12th edition (1964), is compared with several other modern and older systems with the result that no less than 11–13 (and more) families are considered to be centrospermous in the strict sense; to these may be added thePolygonales and, doubtfully, thePlumbaginales andBatidales. As indicated by their name Centrospermae their main character is the central or basal placentation in combination with campylotropy (or amphitropy) of the ovules, seeds with perisperm, and coiled or curved embryos in peripheral position. Other outstanding features are found in the embryology; the ovules are bitegmic-crassinucellate, a nucellar cap is present, as well as an endostome and air spaces; the pollen is trinucleate. Anomalous secondary thickening in stems and roots often occurs. The pollen morphology, specific P-type sieve-element plastids, and the presence or absence of betalains are also important characters. Other floral features, especially the structure of the gynoecium, the androecium, the perianth and the receptacle, as well as the morphology of the inflorescences are of taxonomic importance. The putative relationships of theCaryophyllidae can perhaps best be resolved on the basis of more detailed morphological investigations (e.g. the so-called apocarpy, the development of the androecium, the pollen morphology, chromosome numbers, etc.).Presented in the Symposium Evolution of Centrospermous Families, during the XIIth International Botanical Congress, Leningrad, July 8, 1975.     

S-type sieve-element plastids and anthocyanins inVivianiaceae: Evidence against its inclusion intoCentrospermae

The presence of S-type sieve-element plastids and anthocyanins in theVivianiaceae indicates that it is not a member ofCentrospermae (Caryophyllales).     

Elektronenmikroskopische Untersuchungen zur Frage der verwandtschaftlichen Beziehungen zwischenTheligonum undRubiaceae: Feinbau der Siebelement-Plastiden und Anmerkungen zur Struktur der Pollenexine

Theligonum cynocrambe and 13 species ofRubiaceae contain S-type sieve-element plastids, wide-spread in Dicotyledons. Alignment ofTheligonum toCaryophyllales (Centrospermae), especiallyPhytolaccaceae, is unlikely, because this order is characterized by specific P-type plastids. SEM investigations show the pollen exine ofTheligonum to be microreticulate, with additional supratectate spinules.Asperula and other genera of the tribeRubieae have a tectum perforatum (punctitegillate sexine), also with supratectate verrucae or spinulae.—Thus ultrastructure suggests (but not definitely proves) relationships betweenTheligonum andRubiaceae, while affinities betweenTheligonum andCaryophyllales are excluded.

     

Starch-accumulating (S-type) sieve-element plastids in Hydatellaceae: implications for plastid evolution in flowering plants

TEM investigation of sieve-element plastids in three species of Trithuria, the sole genus of the small aquatic family Hydatellaceae, show that P-type plastids are absent from this genus and only starch-accumulating (S-type) sieve-element plastids are present. This discovery is consistent with the recent transfer of Hydatellaceae from the highly derived monocot order Poales (grasses and their allies) to the early-divergent angiosperm order Nymphaeales (waterlilies) based on molecular phylogenetic data. Species of Poales consistently possess P2-subtype plastids, in common with other monocots, but only S-type plastids are present in Nymphaeales. The results confirm that Hydatellaceae do not belong in monocots. Optimisation of the two major types of sieve-element plastid onto a recent phylogeny of early-divergent angiosperms confirms that S-type is the primitive form and indicates that P-type sieve-element plastids have evolved more than once in angiosperms.     

Serologische Untersuchungen zur Gliederung derBrassicaceae

The serological investigations support the opinion ofJanchen (1942) to combine the generaBunias, Isatis, andSisymbrium in the tribeSisymbrieae; Cheiranthus, Erysimum, andMatthiola in the tribeHesperideae; andBrassica, Crambe, Sinapis, andSuccowia in the tribeBrassiceae. They further underline the central position of theSisymbrieae and the isolated position of theHeliophileae. In accordance withEigner (1973) theBrassiceae are placed closer to theSisymbrieae than inJanchen; the same holds for thePringleeae. No serological justification could be found to uniteArabis andBarbarea in the tribeArabideae, andAlyssum andLunaria in theAlysseae. From the antigen-systems used among the representatives ofJanchen's Lepidieae the generaLepidium andNeslia show remarkable correspondence both toCamelina andThlaspi, but not toCochlearia which appears distant fromCamelina andThlaspi also.

Teil 1/Part 1.     

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.     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

Contributions to the morphology,anatomy, and karyology ofRhabdodendron,and a reconsideration of the systematic position of theRhabdodendronaceae

Rhabdodendron macrophyllum (Spruce ex Benth.)Huber andR. amazonicum (Spruce exBenth.)Huber differ in several anatomical and morphological characters (secretory cavities, hypoderm, peltate hairs, internodal region and petiole). A position of the monotypicRhabdodendronaceae in theCentrospermae as recently suggested is hardly supported: Peltate hairs, lysigenous secretory cavities and spicular cells in the leaves, multilacunar nodes, chromosome number (R. macrophyllum: n = 10; first count for the genus resp. family), ± simultaneous (or slightly centripetal) development of the androeceum, anacrostyly and two ovules in the unicarpellate gynoeceum, apparent disc, monotelic racemes, and data available from literature (pollen, sieve tube plastids) clearly indicate a close affinity toRutaceae, and even make the family rank ofRhabdodendron questionable.     

Phylogenetic relationships of theJuglandaceae

A cladistic analysis of molecular data from the chloroplast generbcL was used to examine the taxonomic relationships of the walnut family (Juglandaceae). In addition, chemical and morphological data from a previous study byHufford (1992) were incorporated, expanded, and analyzed independently and in combination with the molecular data. The results of these analyses suggest that theJuglandaceae are more closely related to theFagaceae, Betulaceae, Casuarinaceae, andUrticaceae and their relatives (sensuCronquist 1981) than they are to theAnacardiaceae (sensuThorne 1983). However, sequence data fromrbcL also suggest a relationship between the higherHamamelidae and certain families in theRosidae sensuCronquist 1981 (such asRosaceae andRhamnaceae), an outcome which would add credence to the widely accepted view of the polyphyletic nature of theHamamelidae.     

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.     

Electron microscopical studies ofThorea ramosissima (Thoreaceae,Rhodophyta): Taxonomic implications ofThorea pit plug ultrastructure

The thallus ofThorea ramosissima was studied electron microscopically. The cells of the medulla, the cortex and the assimilatory hairs differ not only in size and number of plastids and their equipment with thylakoids but also in cell wall structure, the number of mitochondria and the activity of the Golgi apparatus, with dictyosomes transforming complete cisternae into Golgi vesicles with mucilaginous contents in the outer region of the cortex. The pit connections have plugs with a distinct plate—like (not dome-like) outer cap layer. BecauseT. riekei was reported to have dome-like outer cap layers and because this character was the main reason to place theThoreaceae into theBatrachospermales (Pueschel & Cole 1982),T. riekei was reinvestigated, too. A distinct outer cap could not be detected. The reliability of pit plug structure as a taxonomic character and the taxonomic position ofThorea is discussed.     

Weitere Untersuchungen über Proteinkörper in Zellkernen und ihre taxonomische Bedeutung

In 83 species of the familiesMonotropaceae, Apocynaceae, Oleaceae, Scrophulariaceae, Lentibulariaceae, Bignoniaceae, Martyniaceae, Myoporaceae, Verbenaceae, Lamiaceae, Campanulaceae, andLiliaceae, protein bodies in the cell nuclei have been found, in 68 of these species for the first time. On the basis of their structure in accordance with morphological characters the generaBurgsdorfia, Hesiodia, Olisia, andPhlomoides of theLamiaceae are accepted;Lamium is divided intoLamium, Lamiastrum andOrvala; two new combinations are established:Kickxia campyloceras (Rech. fil. &Esfandiari)Speta andEtornotus papilionaceus (Burm. in L.)Speta. Deviating shape or lack of protein bodies corroborate former taxonomic decisions, e.g. the transfer ofMonotropa toMonotropaceae or the separation ofGaleopsis andLadanum; Veronica schmidtiana should not be included inPseudolysimachion. Systematic affinities are discussed primarily withinScrophulariaceae because nuclear protein bodies have been studied already in many species of this family. ForCampanula patula two 2 x populations are reported.

Herrn Professor Dr. L.Geitler zum 80. Geburtstag gewidmet.     

Comparative cytology and taxonomy of theUlvaphyceae II. Ulvalean characteristics of the stephanokont flagellar apparatus ofDerbesia tenuissima

Summary The stephanokont flagellar apparatus of the zoospores ofDerbesia tenuissima (De Not.) Crouan is examined and compared to the flagellar apparatuses of other green algae. The flagella ofDerbesia are attached to two of three bands which lie at the junction of the body and papilla. Serial longitudinal and cross sections reveal that the basal bodies are attached to the bands along their sides and at their proximal ends. The bands are not striated in any plane. The lack of striation in the bands and the partial covering of the proximal end of the basal bodies by one of the bands closely resemble the type of flagellar connection system described as the Bryopsis-type byMelkonian (1980). Zoospores of ulvalean green algae also possess these features, suggesting that green siphons are phylogenetically related to theUlvales. It is proposed that green siphons be tentatively classified in theUlvaphyceae rather than in theChlorophyceae orCharophyceae.This work supported by NSF Grant DEB 78-03554.     

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.