ORIGIN OF TRIPSACUM ANDERSONII (GRAMINEAE)

Tripsacum andersonii Gray (Gramineae) is a species with 2n = 64 chromosomes. Chromosome behaviour during meiosis of microsporogenesis suggests that the species combines three homologous haploid Tripsacum genomes of x = 18 (54 chromosomes), and an alien haploid genome of x = 10 chromosomes. Cytogenetic studies indicate that T. andersonii originated as a hybrid between a species of Tripsacum (2n = 36) and a species of Zea (2n = 20). Comparative morphology and flavonoid chemistry fail to identify the Zea species involved in this intergeneric hybrid. Chromosome morphology suggests that it was either Z. mays L. subsp. mays (domesticated maize) or subspecies mexicana (Schrad.) Iltis (annual teosinte). The Tripsacum parent probably was T. latifolium Hitchc. of Central America. It resembles T. andersonii in vegetative morphology. Tripsacum maizar Hernandez et Randolph and T. laxum Nash, which resemble T. andersonii in flavonoid chemistry, are eliminated as possible parents on the basis of growth habit and the morphology of their hybrids with maize.     

COUNTERFEIT HYBRIDS BETWEEN TRIPSACUM AND ZEA (GRAMINEAE)

Diploid (2n = 36) Tripsacum australe Cutler and Anderson var. hirsutum de Wet and Timothy, T. cundinamarce de Wet and Timothy, T. dactyloides (L.) L. var. dactyloides and var. meridonale de Wet and Timothy, and T. laxum Nash were crossed with Zea mays L. (2n = 20) as the pollen parent. True hybrids combine the cytologically nonreduced genome of Tripsacum (36 chromosomes) with the haploid (10 chromosomes) or more rarely diploid (20 chromosome) genome of Zea. Maternal offspring with 2n = 36 Tripsacum chromosomes commonly result from parthenogenetic development of cytologically nonreduced eggs. Some individuals with 2n = 36 Tripsacum chromosomes, however, resemble true hybrids in phenotype. These counterfeit hybrids incorporated Zea genetic material into their Tripsacum genomes without true fertilization having taken place. Offspring of counterfeit hybrids that were grown to maturity resembled their mothers in phenotype, and must have originated parthenogenetically. It is proposed that counterfeit hybrids are also produced in nature, and that this process contributes to origins of variation in gametophytic apomicts, and perhaps also in sexually reproducing species.     

MORPHOLOGICAL AND CYTOLOGICAL VARIABILITY IN TRIPSACUM DACTYLOIDES (GRAMINEAE)

A total of 235 accessions of Tripsacum dactyloides (L.) L. representing natural populations from 88 locations distributed throughout ten states of the United States were collected in the wild and studied morphologically and cytologically. Multivariate analysis of variance (MANOVA) was applied to 17 morphological characters recorded for 868 specimens from the 88 locations, which were further combined into 25 groups to facilitate analysis. Multivariate F ratios for six comparisons involving different groups were highly significant, indicating that the populations were significantly different on the basis of all 17 characters. Non-significant MANOVA F ratios for two comparisons between sympatric diploid and polyploid accessions showed them to be morphologically similar. Discriminant function (DF) analysis was employed to determine which characters contributed towards group discrimination. No one variable was found to distinguish between groups; rather, a combination of characters was necessary, and the combination changed with each comparison. Accessions were mainly either diploid (2n = 36) or tetraploid (2n = 72), with two triploids (2n = 54) reported from separate locations in Texas. Cytological data revealed that diploids and tetraploids occupy a more sympatric distribution than previously supposed. Morphological analysis suggested that diploids could not always be distinguished from polyploids on the basis of morphology alone, unless the appropriate characters were used. Information from cytological and morphological data showed Tripsacum dactyloides to be composed of many populations covering a wide range of variability, with each population possessing a characteristic combination of morphological attributes. It was concluded that T. dactyloides can be most meaningfully analyzed in terms of particular geographic regions, rather than attempting to elucidate natural relationships by correlating data from the entire United States.     

SYSTEMATICS OF THE TRIBE ORCUTTIEAE (GRAMINEAE) AND THE DESCRIPTION OF A NEW SEGREGATE GENUS,TUCTORIA

The two genera Neostapfia and Orcuttia, recognized as being closely allied and sharing unusual features, are treated as the sole members of the tribe Orcuttieae. Neostapfia is monotypic; Orcuttia comprises eight taxa, six of which are universally treated as species, and two as varieties. Studies reported here are based on field work throughout the ranges of these two genera and examination of 550 herbarium specimens. Chromosome counts and seed protein analyses for all taxa are presented. These data indicate that each taxon is worthy of specific status and that Orcuttia, as traditionally treated, consists of discordant elements. It is concluded that a more satisfactory taxonomy results when this group is split into two genera. A new genus, Tuctoria, is described, and the combinations T. fragilis (Swallen) J. Reeder, T. greenei (Vasey) J. Reeder, and T. mucronata (Crampton) J. Reeder are proposed.     

A BIOSYSTEMATIC STUDY OF TRIDENS (GRAMINEAE)

Tateoka , Tuguo . (U. Montréal, Montréal, Canada.) A biosystematic study of Tridens (Gramineae) . Amer. Jour. Bot. 48(7): 565–573. Illus. 1961.—The genus Tridens has been studied from cytological, morphological, anatomical and histological points of view. Species of Tridens can be divided into 2 groups according to the characters of caryopses, stigmas, lemmas, paleas and general habit. In accordance with the morphological disparities, the 2 groups have different appearances of the anatomy of leaf margins and midribs and also of the bicellular microhairs on the epidermis of the leaf blade. Further, the 2 groups have different basic chromosome numbers, x=8 and x=10, and some distinction in karyotype. Somatic chromosomes of 8 species have been examined. The evidence given by the combined studies indicates that Tridens should be regarded as a mixture of 2 phylogenetically distant groups. Based on this conclusion, the 5 species representing one of the 2 groups (T. pilosus, T. avenaceus, T. grandiflorus, T. nealleyi and T. pulchellus) are transferred to the genus Erioneuron which is hereby revived. Nomenclatural changes are made for the species of the revived genus.     

赤■属的系统学研究

采用比较形态学方法,本文详细地描述了赤属植物根、根状茎、茎、卷须、花序、花萼、花冠、雄蕊群、雌蕊群、果实、种子以及毛被的形态特征,并讨论了某些形态学性状的系统学意义。本文首次描述和记录了该属植物的传粉生物学特征以及传粉媒介,并讨论了造成该属某些种结实率低的原因。本文还根据现存赤属及其近缘属植物的分布式样以及它们的属下分类群的系统演化式样,确定了中国的横断山系和大巴山系地区是该属植物的现代分布中心和分化中心,而中国云南南部和中南半岛北部地区的季节性山地雨林是该属植物的起源中心。在综合大量资料的基础上,本文对赤属作了分类学修订。确认该属有２２种,２变种,归并了２种和１０变种。     

BIOSYSTEMATICS OF THE BOTHRIOCHLOA BARBINODIS COMPLEX (GRAMINEAE)

The New World species of Bothriochloa O. Kuntze are polyploids with 2n = 60, 120, 180 and 220 chromosomes and they reproduce sexually. Plants with 2n = 180 chromosomes constitute the extremely variable B. barbinodis (Lag.) Herter, which is subdivided into var. barbinodis, var. palmeri (Hack.) de Wet comb. nov., and var. schlumbergeri (Fourn.) de Wet comb. nov. The single collection with 2n = 220 chromosomes belongs with var. schlumbergeri. Plants resembling B. barbinodis in inflorescence structure but having well-developed pedicellate spikelets and 2n = 120 chromosomes are included in B. campii (Swallen) de Wet comb. nov. South American collections of B. springfieldii (Gould) Parodi differ from North American collections in having 2n = 60 rather than 120 chromosomes and in having larger inflorescences as does B. barbinodis. Variety australis de Wet. var. nov. is described to include them.     

DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM (BATRACHOSPERMALES,RHODOPHYTA) IN NORTH AMERICA. 3. SECTION SETACEA1

Six populations of Batirachospermum section Setacea from North America were compared to eight type specimens using multivariate morphometrics and image analysis. From this analysis, four species in this section were distinguished worldwide: B. atrum (Hudson) Hartley [syn. B. gallaei Sirodot]; B. orrthostichum Skuja, B. sertularina (Bory) Bory]; B. diatyches Entwisle; B. androinvolucrum sp. nov.; and B. puiggarianum Grunow in Wittrock et Nordstedt (syn. B. angolense Welwitsch ex West et West, B. nigrescens Welwitsch ex West et West). Two of these species were found in North America: B. atrum in California and Texas and B. androinvolucrum in British Columbia, Washington State, and Alabama. The new species, B. androinvolucrum, is distinguished by having spermatangia restricted to one-celled involucral bracts of the carpogonial branch.     

DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM(BATRACHOSPERMALES,RHODOPHYTA) IN NORTH AMERICA. 6. SECTION TURFOSA1

Twenty-one populations of Batrachospermum section Turfosa from North America were compared to nine type and two historically important specimens using multivariate morphometrics and image analysis. The protologues of six other infrageneric taxa were also compared. From this analysis, six species are recognized worldwide: B, de-sikacharyi Sankaran, B. gombakense Kumano et Ratnasabapathy, B. keratophytum Bory de Saint-Vincent [syn. B. vagum var. keratophytum (Bory de Saint-Vincent) Sirodot, B. gulbenkianum Reis, and B. suevorum Kützing nom. Meg.], B. sinense Jao, B. turfosum Bory de Saint-Vincent [syn. B. vagum (Roth) C. Agardh and B. vagum var. undulato-pedicellatum Kumano et Watanabe], and B. vogesiacum F. G. Schultz ex Skuja [syn. B. vagum var. flagelliforme Sirodot, B. flagelliforme (Sirodot) Necchi], These species are distinguished on the basis of carposporophyte-bearing branch cortication, secondary fascicle development, monoecy or dioecy, presence of spermatangia on involucral filaments and monosporangia, and dimensions of trichogynes and carposporangia. Peripheral cortication has been previously used to separate species in this section, but we observed that this feature is quite widespread in the section. Presence of indeterminate gonimoblast filaments has been reported for some taxa in section Turfosa, but no such structures were seen in any of the specimens examined. Only B. keratophytum has been collected in North America, ranging from southwestern Greenland (64°N) to Louisiana (30° N).     

THE SYSTEMATICS AND ANATOMY OF GONGYLOCARPUS (ONAGRACEAE)

The unique fruiting structures of the closely related, principally Mexican, monotypic genera Gongylocarpus and Burragea (Onagraceae) compelled a detailed anatomical and cytological investigation of these plants which led to the conclusion that they should be included in a single genus, Gongylocarpus. Gongylocarpus fruticulosus (Burragea), endemic to two adjacent islands off the west coast of Baja California, is divided into two subspecies, subsp. fruticulosus and subsp. glaber. The vegetative and floral anatomy, including wood anatomy, of both species is described. The fruits of these two species grow into the stem by meristematic activity during the course of ontogeny, the ovaries in the mature flower being superficial and sessile in the leaf axil. There is no pedicel associated with the flower, but only a branch gap. Meristematic tissue at the base of the locules divides rapidly at a relatively late ontogenetic stage, the ovaries growing downward into the stem and crushing the pith. The mature, heavily sclerenchymatous fruits are located wholly within the stem, and in G. fruticulosus they are aggregated into long chains. Both species have a gametic chromosome number of n = 11, a characteristic otherwise unknown in the tribe Onagreae but shared with other generalized groups in the family. Taken together with other features, this suggests a primitive position within the tribe for Gongylocarpus.     

THE EVOLUTION AND SYSTEMATICS OF BEE-EATERS (MEROPIDAE)

Behavioural and ecological characters are used in addition to structural ones in considering the systematics of the Meropidae. The two species of Nyctyornis are the most primitive extant forms. Meropogon is retained as a monotypic genus for forsteni, and all other bee-eaters are placed in the single genus Merops, being ecologically and morphologically rather uniform except in details of wing and tail structure, which should be considered only of specific importance. M. breweri and M. oreobates are thought to be secondarily rather than primarily forest species. With the submergence of Aerops and Melittophagus, and the monotypic genera Bombylonax and Dicrocercus, which are considered to be closely related to the pusillus species-group, Merops is enlarged to 21 species which are uniform except in tail-shape, wing formula and throat feather structure. These characters are of specific importance only, and have a mosaic distribution within the genus. Their use in the definition of the formerly recognized genera results in an artificial classification. The proposed delimitation of species-groups within Merops differs somewhat from previous arrangements, and affinities argued in the text are summarized in Fig. 15, which shows superspecies and species-groups. The species recognized are formally tabulated below. The Meropidae probably originated in southeast Asian forest and spread through former forest to Africa. Only in Africa was the open-country environment invaded, and speciation in the savanna was in two main directions, producing small sedentary and large migratory species. Representatives of both types returned to Asia in open country. From the present distribution of species it is inferred that speciation has proceeded under the main influences of (1) isolation of a population and its habitat in Pleistocene Africa and (2) isolation of migrants away from their breeding range. The distributions of species with wide or rather limited ranges are discussed in terms of physiological adaptation and ecological competition. Opinion has not been expressed on the validity of subspecies, which have been discussed only in delimiting controversial species. In the following summary, the only subspecies named are those affected by changes from Peters' scheme (cf. Table 1). Superspecies are bracketed. Nyctyornis amicta N. athertoni Meropogon forsteni Merops guloris M. mülleri M. bulocki M. bullockoides M. pusillus M. variegatus (?loringi, oariegatus, lafresnayii, bangweoloensis) M. oreobates M. hirundineus M. breweri M. revoilii M. albicollis M. orientalis M. boehmi M. viridis M. superciliosus (persicus, chrysocercus, superciliosus) M. philippinus (philippinus, salvadorii) M. ornatus M. apiaster M. leschenaulti M. malimbicus M. nubicus (nubicus, nubicoides)     

FLAVONOID CHEMISTRY AND SYSTEMATICS OF TITHONIA (COMPOSITAE)

Twenty-four flavonoid compounds, including chalcones and aurones, are reported from 13 taxa of Tithonia. Pedunculin (4′, 6, 7-trimethoxy, 5, 8-dihydroxyflavone), also is characterized. The distribution of these compounds is compared to the existing classification of the genus based primarily on morphological data. By comparison with the previously proposed phylogeny of the genus, the evolution of the flavonoid system may be elucidated. It is proposed that the ancestral stock of Tithonia had flavonols, di- and tri-methoxyflavones, and 6-methoxyflavones. From this ancestral stock, a number of trends have occured in derivative taxa. These trends are: 1) a maintenance of a diversity of compounds in several evolutionary lines, 2) a reduction in the number of methoxyl substitutions, and 3) the elaboration of 5-deoxyflavones and flavonols.     

TISSUE CULTURE AND REGENERATION OF DISTICHLIS SPICATA (GRAMINEAE)

Distichlis spicata tissue cultures were initiated from mature seeds. Cultures displayed regenerable callus that was compact, white, and streaked with purple and green. Selection of compact areas at subculture established long-term, regenerable cultures. Removal of auxin and inclusion of 1 mg 1^–1 BA in the maintenance media induced regeneration. Histological sections indicate that although cells were typical of embryogenic types, regeneration was by shoot organogenesis. Regenerated plants flowered and set seed under field conditions.     

盅口族线虫分类系统评述(线虫纲:圆线科)

对盅口族Cyathostominea线虫分类系统的研究进行了回顾和讨论,根据各分类学家的意见,笔者提出了盅口族线虫的分类系统,该系统以Lichtenfels等人（1998）的观点为基础,其不同点在于：1）将马线虫属Caballonema Abulasze,1937和柱咽属Cylindropharynx Leiper,1911从盅口族中移出,放入柱咽族Cylindropharyngea Popova,1952;2)Scialdo-Krecek(1984)描述的Cylicodon-tophorus reineckei应归属于副杯口属Parapoteriostomum Hartwich,1986.     

A SYSTEMATIC STUDY OF PENNISETUM SECT. PENNISETUM (GRAMINEAE)

Pennisetum sect. Pennisetum includes two reproductively isolated species. Pennisetum purpureum Schumach. is a tetraploid (2n = 28) perennial species which occurs throughout the wet tropics of the world. Pennisetum americanum (L.) Leeke is a diploid (2n = 14) annual species, native to the semi-arid tropics of Africa and India, and contains three morphologically diverse subspecies. Subspecies americanum includes the wide array of cultivated pearl millets. Subspecies monodii from the Sahel of West Africa is identified as the wild progenitor of pearl millet. Subspecies stenostachyum is morphologically intermediate between subsp. americanum and monodii and includes the mimetic weeds often associated with the cultivation of pearl millet.     

AN ANATOMIC-SYSTEMATIC STUDY OF THE CLASSICAL TRIBE FESTUCEAE (GRAMINEAE)

Using the classical tribe Festuceae as a frame of reference, 135 grass genera have been examined in an effort to determine natural generic relationships which often have been obscured by parallel and convergent evolution. Studies of embryo and leaf structure, ligules, lodicules, and lemmas have greatly enlarged, verified, and nearly completed existing evidence that the classical concept of the Festuceae is highly artificial and that the tribe contains many genera which are only remotely related. A more nearly phylogenetic system is achieved when more than two-thirds of these genera are distributed among 4 major groups, which may be worthy of subfamily rank: 55 genera are retained in the festucoid group, 46 are moved to the eragrostoid, 2 to the bambusoid, 13 to the arundoid, and 8 to a recently designated group labelled the centothecoid. Three genera remain unplaced; and material was unavailable or insufficient to make accurate determinations for 8 genera.     

POLLINATION AND THE FUNCTION OF FLORAL PARTS IN CHAMAECRISTA FASCICULATA (FABACEAE)

Chamaecrista fasciculata has a rigid upper petal that curves over nine of the ten anthers. The single anther is deflexed, as is the style. An experimental pollination study was designed to test the hypotheses that: 1) the rigid petal acts as flight guide to ensure pollination; and 2) the nine grouped anthers serve as fodder anthers, whereas the single deflexed anther functions in pollination. The rigid petal was removed from 97 flowers. Only 5% of the manipulated flowers set fruit in comparison to a fruit set of 47% for the control group. The results of the study support the flight guide hypothesis. Pollen from both sets of anthers is viable and germinates on receptive stigmas. A pollen flow experiment using powdered metals, backscatter scanning electron microscopy, and X-ray microanalysis revealed that there is no difference in the frequency of pollen distribution from either set of anthers. Therefore, this study refutes the fodder/pollinating anther hypothesis.