PALYNOLOGY AND SYSTEMATICS OF THE LYTHRACEAE. I. INTRODUCTION AND GENERA ADENARIA THROUGH GINORIA

A palynological survey, including LM, SEM, and TEM, is presented for 10 genera of the Lythraceae s.s. (plus Alzatea to be assigned separate family status): Adenaria, Ammannia, Capuronia, Crenea, Cuphea, Decodon, Didiplis, Diplusodon, Galpinia, and Ginoria. Discussion of the results is deferred until the survey is complete, but already information of taxonomic interest is available for the 11 genera studied. The pollen data, consistent with results from cytology, anatomy, and embryology, suggest the current subgeneric classification into the Tribes Lythreae and Nesaeeae based on complete or incomplete septation of the ovary is not valid. The pollen of Alzatea is a generalized type and lacks the morphological features most characteristic of the Lythraceae (pseudocolpi, sculptured exine). The genus is being described as a separate family, and the pollen morphology is consistent with this treatment. The pollen of Cuphea is more diverse and shows little similarity to other genera in the family. It also has a unique combination of floral characters and lipid chemistry that suggests a separate category within the developing subfamilial classification of the Lythraceae.     

PALYNOLOGY AND SYSTEMATICS OF THE LYTHRACEAE. III. GENERA PHYSOCALYMMA THROUGH WOODFORDIA,ADDENDA, AND CONCLUSIONS

Pollen of the 27 genera presently recognized as comprising the family Lythraceae have been surveyed with light microscopy and scanning and transmission electron microscopy. Results for five genera (Physocalymma, Pleurophora, Rotala, Tetrataxis, Woodfordia), in addition to Duabanga, Sonneratia, and Punica (assigned to the Lythraceae in some classifications), are presented here; the remaining genera were treated previously in the series. The family is revealed as the most diverse palynologically of the order Myrtales. The most simple pollen type and the one common to the largest number of genera is prolate-spheroidal to prolate; tricolporate, without pseudocolpi; psilate, scabrate or finely verrucate; and 16–28 μm or less in length. Specializations include oblate grains, development of pseudocolpi (three or six in number), diversification of exine sculpturing, broadening of the colpal and pseudocolpal areas, and reduction in the conspicuousness of the colpi. Pollen evidence provides qualified support for inclusion of Punica in the Lythraceae, the generalized nature of the pollen tempering the conclusion, and little support for inclusion of Sonneratia and Duabanga in the family. Completion of the survey provides a data base of pollen characters that will be integrated in future studies with other evidence into an overall phenetic and cladistic assessment of the family leading to production of a more natural classification.     

PALYNOLOGY AND SYSTEMATICS OF CUPHEA (LYTHRACEAE). II. POLLEN MORPHOLOGY AND INFRAGENERIC CLASSIFICATION

Present taxonomic studies in Cuphea (Lythraceae) reveal that a broad spectrum of biosystematic data is required for an understanding of evolutionary relationships among this large and complex group of species. As part of these studies pollen data have proven to be of greater pragmatic value than is frequently true for more stenopalynous taxa. A survey is made of pollen types in 160 species of Cuphea with special reference to specific taxonomic problems, and a summary presented of points at which pollen data can profitably contribute to taxonomic revision of the genus.     

PALYNOLOGY AND SYSTEMATICS OF CUPHEA (LYTHRACEAE). I. MORPHOLOGY AND ULTRASTRUCTURE OF THE POLLEN WALL

A survey of pollen from 153 species of Cuphea has revealed a remarkable array of morphological forms. The survey involved light and electron microscope investigations of C. crassiflora, jorullensis, and koehneana to determine details of exine morphology, and a more general study of pollen from an additional 150 species. Comparison of pollen types within a single morphological category and within taxonomic groups (i.e., sections or subsections) indicates considerable variation at subgeneric levels. The genus is distinctly eurypalynous, and the extent to which pollen varies among the sections, subsections, species and varieties is probably exceeded by few genera of comparable size. The pollen is also variable within each taxon, but size studies of single-anther lactic acid preparations demonstrate the genus is not polymorphic, as in Lythrum, where pollen polymorphism is associated with heterostyly. The latter phenomenon is as yet unknown in Cuphea. These results reveal that pollen morphology constitutes an important and useful character for taxonomic studies of Cuphea.     

RESTRICTION FRAGMENT ANALYSIS OF CHLOROPLAST DNA AND THE SYSTEMATICS OF VIGUIERA AND RELATED GENERA (ASTERACEAE: HELIANTHEAE)

Phylogenetic relationships among 31 species representing variously Helianthus, Helianthopsis, Heliomeris, Simsia, Viguiera, and Tithonia were assessed by chloroplast DNA restriction site mapping. A total of 147 mutations including 92 informative ones was detected using 16 restriction enzymes, with an estimated sequence divergence within the group of 1.4%. Parsimony analysis produced a single most parsimonious tree with a length of 161 steps and a consistency index of 0.91. Statistically significant clades, as assessed by the bootstrap method, correspond to a number of taxa recognized previously, including Helianthus (3 species), Helianthopsis (5 species), and several groups within Viguiera, including sect. Maculatae (4 species), the Baja California group (6 species), sect. Paradosa (2 species) and V. dentata (3 samples). However, species of Viguiera collectively form a highly paraphyletic group relative to species of other genera. Helianthus and Helianthopsis were separated into different clades, supporting their recent segregation. Placement of H. porteri in Helianthus rather than Heliomeris was confirmed; the single sample of the latter genus was most similar to the Baja California group of Viguiera. An expected relationship between Simsia (2 species) and one member of Viguiera ser. Grammatoglossae was confirmed (although not with two other putatively related members of Viguiera) and an unexpected relationship between Simsia and Tithonia was suggested. The presence of Mexican taxa as the more basal groups in the tree points toward a possible Mexican origin for Viguiera and related genera. A molecular clock hypothesis is rejected in many pairwise comparisons involving woody taxa with herbaceous ones, although it could not be rejected in most pairwise comparisons involving taxa of similar habit.     

HYBRIDS AND PHYLOGENETIC SYSTEMATICS II. THE IMPACT OF HYBRIDS ON CLADISTIC ANALYSIS

I examined three aspects of the cladistic treatment of a set of 17 F₁ hybrids of known parental origin: (1) impact of hybrids on consistency index (CI) and number of most parsimonious trees (Trees), (2) placement of hybrids in cladograms, and (3) impact of hybrids on hypotheses of relationship among species. The hybrids were added singly and in randomly selected sets of two to five to a data set composed of Central American species of Aphelandra (including the parents of all hybrids). Compared to analyses with the same number of OTUs all of which were species, the analyses with hybrids yielded results with significantly higher CI. There was no difference in Trees between analyses with hybrids versus species. There was thus no evidence that hybrids would appear to be more problematic for cladistic methods than species. Accordingly, hybrids will not be readily identifiable as taxa that cause marked change in these indices. About % of the hybrids were placed as the cladistically basal members of the lineage that included the most apomorphic parent. Relatively apomorphic hybrids were placed proximate to the most derived parent (ca. 13% of hybrids). Other placements occurred more rarely. The most frequent placements of hybrids thus did not distinguish them from normal intermediate or apomorphic taxa. When analyses with hybrids yielded multiple most parsimonious trees, these were no more different from each other than were the equally parsimonious trees that resulted from analyses with species. Most analyses with one or two hybrids resulted in minor or no change in topology. When hybrids caused topological change, they frequently caused rearrangements of weakly supported portions of the cladogram that did not include their parents. When they disrupted the cladistic placement of their parents, they often caused their parents to change positions, with at least one topology bringing the parental lineages into closer proximity with the hybrid placed between them. Hybrids between parents from the two main lineages of the group caused total cladistic restructuring. In fact, the degree of relationship between a hybrid's parents (measured by both cladistic and patristic distance) was strongly correlated with CI (negatively) and with the degree of disturbance to cladistic relationships (positively). Thus, hybrids between distantly related parents resulted in cladograms with low CI and major topological changes. This study suggests that hybrids are unlikely to cause breakdown of cladistic structure unless they are between distantly related parents. However, these results also indicate that cladistics may not be specially useful in distinguishing hybrids from normal taxa. The applicability of these results to other kinds of hybrids is examined and the likely cladistic treatment of hybrids using other sources of data is discussed.     

THALASSIOMYCETES II. NEW GENERA AND SPECIES OF DEUTEROMYCETES

Meyers , Samuel P. (U. Miami, Coral Gables, Fla.) and Royall T. Moore . Thalassiomycetes II. New genera and species of Deuteromycetes. Amer. Jour. Bot. 47(5) : 345-349. Illus. 1960.–On the basis of taxonomic studies, 3 new monotypic thalassic genera are erected. These are: Cirrenalia, type C. macrocephala (=Helicoma macrocephala Kohlmeyer) ; Cremasteria, type C. cymatilis; Culcitalna, type C. achraspora . Also described is a new species of Humicola, H. alopallonella, which constitutes the first report of this genus from the marine environment.     

THE SYSTEMATICS AND PHYLOGENETIC RELATIONSHIPS OF VETULICOLIANS

Abstract:  Vetulicolians have variously been considered to be unusual arthropods, stem-group deuterostomes or relatives of the tunicates. They are known from a number of Cambrian Lagerstätten, and are particularly diverse in the Chengjiang biota of Yunnan Province, China. We recognize two classes, Vetulicolida and Banffozoa, which together form a monophyletic group. Within the Chinese collections we also identify two new species and recognize one new genus: Vetulicola monile sp. nov. and Bullivetula variola gen. et sp. nov. The evidence from new and previously described specimens is used to undertake a phylogenetic analysis and to evaluate a range of hypotheses for the affinities of vetulicolians. Given the difficulties of interpreting features in enigmatic fossils and the apparently contradictory set of characters possessed by vetulicolians, it is not possible on current evidence to reach an unequivocal conclusion regarding the phylogenetic position of the group. One possibility is that they are a sister group of arthropods that lost limbs but gained gill structures analogous to those of deuterostomes, but several features remain unexplained by this model. If they are protostomes, a more generally parsimonious position is close to the kinorhynchs. An alternative is that they are deuterostomes, although a placement at the base of the clade is not supported by the evidence. If they are deuterostomes, it is more likely that they are close to the tunicates.     

菖蒲属系统学研究的进展与菖蒲科的重新确立

本文介绍了菖蒲属系统地位的变化情况,综述了菖蒲属(Acorus L.)从天南星科(Araceae Jussieu)中分离出来独立成科的形态学、解剖学、胚胎学、细胞学、植物化学、分子生物学等多方面的证据,并对菖蒲科(Acoraceae C. A. Agardh)系统关系的研究进展进行了总结。     

基于ITS1 DNA序列分析的几种酵母菌的分子分类

采用ITS1序列分析的手段。对来自Dekkera/Brettanomyces/Eeniella的15株菌株进行了分子分类学的研究。研究结果支持4个Dekkera/Brettanomyces种类的确认;D.anomala/B.anomalus,D.bruxellensis/B.bruxellensis,D.custersiana和D.naardenensis,以及把E.nana合并于Brettanomyces属的建议,此外,研究也揭示了ITS1在酵母分子分类学中的价值。     

菊科植物的系统分类与区系地理的初步探讨

本文论述了菊科系统分类与区系地理特点。作者将菊科区分为二亚科、5超族、12族,同时将菊科世界区系分4大区、27亚区加以讨论。     

SYSTEMATICS OF THE CALCIFIED GENERA OF THE GALAXAURACEAE (NEMALIALES,RHODOPHYTA) WITH AN EMPHASIS ON TAIWAN SPECIES1

The current separation of the calcified genera Actinotrichia Decaisne, Galaxaura Lamouroux, and Tricleocarpa Huisman et Borowitzka in the Galaxauraceae is largely based on type of life history (whether the gametophytes and tetrasporophytes are isomorphic or heteromorphic with respect to gross morphology or cortical‐cell features) and on features of postfertilization development (such as the composition of the pericarp). We reexamined the phylogenetic relationships of these genera based on comparative rbcL sequence analysis, types of life cycle, and cystocarp development. Four distinct assemblages have been identified: an Actinotrichia clade, a Tricleocarpa clade, a Galaxaura clade (containing the type species), and a Dichotomaria clade made of a number of formerly Galaxaura species (D. obtusata [Ellis et Solander] Lamarck, D. marginata [Ellis et Solander] Lamarck, and D. diesingiana [Zanardini] Huisman, Harper and Saunders). Key differences between Dichotomaria and Galaxaura include the habit of the gametophytic and tetrasporophytic generations (isomorphic in Dichotomaria and dimorphic in Galaxaura) as well as the presence or absence of a persistent pericarp in the cystocarp (present in Dichotomaria and absent in Galaxaura). Molecular data do not support monophyly for the putatively pantropical species Galaxaura rugosa, Dichotomaria obtusata, and D. marginata, all of which we conclude are in need of taxonomic revision.