Cytotaxonomic Studies Research Articles

A cytotaxonomic study of Australian Cardamine

A cytogenetic study of Cardamine, based on material collected in southern New South Wales and the Australian Capital Territory, indicated the presence of at least six distinct species in this area. Two species, the 16-chromosome C. hirsuta and the 32- chromosome C. flexuosa, were introduced with white settlement. The other four species are native to the area, occupying a variety of habitats between sea-level and 7200 ft. One species, with a somatic chromosome number of 64, is confined to altitudes below 4000 ft, whereas the other three species (2n = 48) are found only above 4000 ft. Of the 48-chromosome species, one comprises a single population found at Mt. Franklin and the remaining two are confined to particular altitudinal ranges, one between 4000 and 5400 ft and the other between 5200 and 7200 ft. All four native species are completely isolated from one another by the inviability of the F1 hybrids. Within species, however, all populations were fully interfertile and there was no evidence of any other form of reproductive isolation. Despite the magnitude of reproductive isolation there were no distinct morphological differences between the native species except in the case of the 48-chromosome form from Mt. Franklin, which had entire rather than pinnate leaves. The other three species were in fact more comparable to ecotypes in respect of their altitudinal distribution and the degree of morphological differentiation. Speciation mechanisms involved in the evolution of the native species of Cardamine are discussed.

New Bryophytes for Colorado

Mnium ambiguum H. Miill., M. andrewsianum Steere, and M. trichomanes Mitt. are reported from Colorado, and their known ranges thereby significantly extended. The moss genus Mnium has been known in Colorado by the species M. arizonicum, M. blyttii, M. cuspidatum, M. lycopodioides, M. marginatum, M. medium, M. orthorrhynchum, M. pseudopunctatum, M. punctatum, M. punctatum var. elatum, and M. rugicum (Grout 1940). In connection with cytotaxonomic studies of the genus (Bowers 1966), three species previously unknown for the state have been discovered, namely M. ambiguum, M. andrewsianum, and M. trichomanes. These additions are of a considerable phytogeographic significance, widely extending the known distribution of the species. The specimens cited were collected in 1963 to 1965, and they are preserved in the University of Colorado Museum. MNIUM AMBIGUUM H. Mill. The distribution of forms referable to this species has previously been limited to two localities in the United States: Rockland County, New York, and Bergen County, New Jersey (Grout 1903). The species also occurs in Europe (Miiller 1866). The present Colorado collections were all made above an elevation of 8,500 feet and they represent the first report of the species from the southern Rocky Mountains. Perhaps the species has been overlooked in North America and, if definitely searched for, will be found better represented than the present literature indicates. COLORADO. GRAND CO.: West St. Louis Creek, Fraser, Bowers bb-553. Berthoud Pass, Bowers bb-556. W of Berthoud Pass on U.S. 40, Bowers bb-559. EL PASO CO.: Pike's Peak, W of Colorado Springs, Bowers bb-624. MNIUM ANDREWSIANUM Steere. This taxon is distributed throughout Alaska, Canada, and Greenland. It is also reported for Michigan (Mazzer & Sharp 1963). The Colorado collections constitute the second report from the United States outside of Alaska and the first report from the southern Rocky Mountains. The closest known locality is at the edge of the tundra near Athabasca Glacier, Columbia Icefields, Jasper National Park, Alberta, Canada (Steere 1958). Dr. W. C. Steere suggested to me that this species be looked for at high altitudes in Colorado, and collections were subsequently made at altitudes from 8,500 to 11,300 feet. This report extends the range to a new southern limit in western North America. The Colorado specimens differ from the typical M. andrewsianum only in being more robust. COLORADO. GRAND CO.: West St. Louis Creek, Fraser, Bowers bb-185. Berthoud Pass, Bowers bb-554. W of Berthoud Pass on U.S. 40, Bowers 1 Department of Biology, University of Colorado, Boulder, Colorado. Present address: Department of Biology, Northern Michigan University, Marquette, Michigan. This content downloaded from 157.55.39.255 on Wed, 25 May 2016 06:37:29 UTC All use subject to http://about.jstor.org/terms 1966] BOWERS: BRYOPHYTES FROM COLORADO 369 bb-557. LARIMER CO.: Poudre Lake, Rocky Mountain National Park, Bowers bb-194. BOULDER CO.: Jenny Lake, Rollins Pass, Bowers bb-194. MNIUM TRICHOMANES Mitt. The distribution of forms referable to this species has previously been limited to two localities in the United States: Florida (Lowry 1948) and Illinois (Andrews 1959). It is widespread in Asia (Noguchi 1960). The Colorado specimens are the first report from the southern Rocky Mountains. It has probably been overlooked in North America and Europe. COLORADO. DOUGLAS CO.: Jackson Creek Road, 11.5 mi from the junction of Colorado 105, Bowers bb-200. Jackson Creek Road, 10 mi from the junction of Colorado 105, Bowers bb-204.

Cytotaxonomic Studies of Freshwater Gastropods (I)

Cytotaxonomic Studies of Freshwater Gastropods (I)

Cytotaxonomic Studies on Mosses from Washington and Idaho

Cytotaxonomic Studies on Mosses from Washington and Idaho

Cytotaxonomic Studies on Mosses from Washington and Idaho

Meiotic chromosome counts were made of 22 Washington and Idaho mosses in 14 genera and eight families. The chromosome numbers for 20 taxa are reported for the first time and two other taxa have been found to have a chromosome number different from that previously reported. This report is a continuation of a cytotaxonomic study undertaken in the course of assisting Dr. Elva Lawton in the preparation of a moss flora of the Pacific Northwest. The meiotic chromosomes of the spore mother cells were studied with the cytological techniques described in an earlier report (Ireland 1963). Acetic-orcein was used exclusively in the present study since it was found to be the most effective in producing the greatest contrast between the chromosomes and the cytoplasm. The collections cited in this paper are represented by voucher specimens in the University of Washington herbarium. The counties cited are in Washington unless stated otherwise. DITRICHUM MONTANUM Leib., n=13 (Fig. 1). Skamania Co., July 12, 1964. RRI-8833. The number n=13 for this autoicous species agrees with some of the other reports for the autoicous members of Ditrichum subgenus Ditrichum. The meiotic chromosomes are similar in staining qualities and behavior to those described for D. pallidum (Hedw.) Hampe (Al-Aish & Anderson 1961). Morphologically, however, the chromosome complement differs from it and from the other autoicous species studied thus far by having one bivalent noticeably larger than the other 12 (Fig. 1). A large and conspicuous bivalent is also found in the complement of other members of the family Ditrichaceae, specifically D. cylindricum (Hedw.) Grout (as Trichodon cylindricus (Hedw.) Schimp., Steere 1954) and Ceratodon purpureus (Hedw.) Brid. (Steere, Anderson, & Bryan 1954). Ditrichum montanum was considered to be a rare moss in the western United States for many years. Anderson and Bryan (1958a), in a cytotaxonomic revision of the autoicous species of Ditrichum subgenus Ditrichum, were unable to obtain cytological material of this species. Furthermore, they were able to locate only four herbarium specimens, collected in Washington and Idaho, which they 1 This study was supported by grant G-19332 from the National Science Foundation to the University of Washington. I am especially grateful to Dr. Elva Lawton and Dr. A. R. Kruckeberg of the University of Washington for their help. I wish to thank Dr. and Mrs. N. Higinbotham of Washington State University for collecting some of the cytological material. 2 Department of Botany, University of Washington, Seattle, Washington 98105. This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 04:50:03 UTC All use subject to http://about.jstor.org/terms 1965] IRELAND: CYTOTAXONOMY OF MOSSES 73

Cytotaxonomic Studies in Apocynaceae and Delineation of the Different Evolutionary Tendencies Operating within the Family

SUMMARY1. A cytotaxonomic study of the family. Apocynaceae representing 24 genera and comprising of 48 species and varieties has been made. Thirty of these plants representing 11 genera have been karyologically investigated for the first time. In the remaining 18 plants where some cytological informations were available, karyotypic analyses of the mitotic chromosomes have been reported for the first time in 5 and meiotic study in 2 of them. Up-to-date informations available in 87 species and varieties from the works of different authors have been tabulated.2. The chromosome numbers in different genera of this family reported earlier and observed during the present investigation has revealed the presence of the following basic numbers: 8, 9, 10, 11, 12, 16 (8), 18 (9) and 23. About 76 per cent of the plants have the basic chromosome numbers of ten and eleven; 11.9 per cent show nine or multiple thereof; 5.9 per cent show twenty-three; 3.0 per cent show eight or multiple thereof and 3.0 per cent show twelve as their basic chromosome numbers.3. The subfamily Plumieroideae comprises genera with a wide variation in chromosome numbers which range from 2n = 16 to 2n = 92. In the other sub family Echitoideae most of the plants have 2 n = 20 and 22 chromosomes, and a couple of them 2 n = 24.4. New polyploid series have been detected in 3 out of the 24 genera studied, where 3 series were reported earlier. The frequency of polyploid species and varieties is about 12.5 per cent in Apocynaceae, estimated from 48 species and varieties of this project and 10.5 per cent when all the previous reports were taken into consideration. All the polyploid species and varieties are confined to the subfamily Plumieroideae.5. The chromosomes are small ranging from 0.7 μ, to 4.8 μ in length and the plants of the subfamily Echitoideae have, in general, smaller chromosomes having none longer than 3.4 μ.6. The chromosomes have mostly median to submedian and in a few cases subterminal primary constrictions. Considerable variation exists in the karyotype within varieties and between species. Chromosomes with secondary constrictions could be detected in most of the plants varying from 2 to 8 in number.7. On the basis of this cytotaxonomic study, it is evident that the plants of the two subfamilies — Plumieroideae and Echitoideae of SCHUMANN are natural groups conspicuously differing in several characters. The following conclusions have been drawn: The genus Allamanda is quite distinct for its fewer and larger chromosomes. Vinca rosea L. on the basis of its morphological and cytological characteristics should be transferred from Vinca Linn, to Lochnera Reich, and called Lochnera rosea (L.) Reich. The subtribe Alstoniinae is a heterogeneous group as it has plants with different habits and chromosome numbers. It is desirable to separate Lochnera, Vinca and Amsonia into a new subtribe. The status of Plumeria in this subtribe needs a thorough reinvestigation. The position of the genus Thevetia with 2 n = 20 chromosomes, syncarpous pistil and funnel-shaped corolla in the subtribe Cerberineae is ambiguous. The tribe Echitideae may be conveniently divided into the two sub-tribes — all the woody climbers in one and the plants with shrubby habits viz. Strophanthus and Nerium in another. It also seems reasonable to transfer the genus Vallaris from the tribe Parsonsieae to the tribe Echitideae and be placed in the new subtribe with the woody climbers.

Chromosome Studies on Mosses from the State of Washington

Chromosome counts are reported for 31 species of Washington mosses, representing 23 genera and 15 families. The chromosome numbers for Brachythecium frigidum (C. Mill.) Besch. (n 6), B. leibergii Grout (n = 10), and Scleropodium obtusifolium (Hook.) Kindb. in Mac. & Kindb. (n = 11) are reported for the first time. The purpose of this study is to further our knowledge of the chromosome numbers of Washington mosses. It is a continuation of a cytotaxonomic study started in 1962 while I assisted Dr. Elva Lawton in the preparation of a moss flora of the Pacific Northwest. The chromosome numbers for 28 taxa, of which 26 were reported for the first time, were published in two earlier reports (Ireland, 1964, 1965). The cytological techniques are the same as those adopted in the previous studies. All the counts were made from spore mother cells at meiosis, with the exception of Pogonatum alpinum and Tetraphis pellucida which were counted from mitotic divisions in young archesporial cells. Voucher specimens of all collections cited are in the University of Washington herbarium, and some are in the National Museum of Canada. BRACHYTHECIUM FRIGIDUM (C. Miill.) Besch., n 6 (Fig. 1-5). Kittitas Co., September 21, 1965. Ireland & Largent 9534. Snohomish Co.' September 26, 1965. Largent 246. Snohomish Co., October 21, 1965. Largent & Iwatsuki 250a, 250b. Meiosis occurs in this polymorphic species when the capsule is light green and 1 This study was supported by grant B-15397 from the National Science Foundation to the University of Washington. I am grateful to Dr. Elva Lawton, Mr. David Largent, and Dr. Z. Iwatsuki for their help. 2 National Muesum of Canada, Ottawa 4, Ontario, Canada. This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:22:01 UTC All use subject to http://about.jstor.org/terms 336 THE BRYOLOGIST [Volume 70

CHANGES IN THE VARIATION PATTERN OF A HYBRID POPULATION OFHELIANTHUSOVER AN EIGHT-YEAR PERIOD

Recent studies of natural populations of higher plants have pointed consistently to the hypothesis that hybridization between populations having markedly different adaptive properties, particularly if it occurs in a disturbed, changing environment where new ecological niches are likely to be available, is one of the strongest factors bringing about evolutionary change (Stebbins, 1959). Consequently studies of such populations, even if carried out over the relatively short periods of time available to the average investigator, should yield valuable information about the evolution of natural populations. The annual species of Helianthus, or sunflowers, are particularly favorable for this purpose. They are variable, widespread, and weedy, entering often into disturbed habitats. They are cross-fertilizing, due to self-incompatibility. Hybridization between species occurs frequently, and the interspecific hybrids, although highly sterile, nevertheless can produce some offspring, particularly through backcrossing, or introgression. There is some evidence that the variation of some species has been increased by this process. Since all of the annual species have the same chromosome number, n= 17, evolution within the group has not involved polyploidy. Finally, the group has been subjected to a series of careful cytotaxonomic studies by Heiser (1947, 1949, 1951a,b, 1954) from whose work the above information was obtained. The two annual sunflowers of California, Helianthus annuus and H. Bolanderi, occupy different ecological niches. The former is a weed of roadsides, very common in the Central Valley and in Southern California. The commonest subspecies is subsp. lenticularis (Dougl.) Ckll., which was already in the state when the first botanical collections were made, and was used by the Indians for various purposes (Heiser, 1949). Since it does not now occur in natural sites in California, it was very likely introduced originally by the Indians from farther east. Since the advent of the white man, repeated introductions from the eastern states have almost certainly been made. The cultivated sunflower, H. annuus subsp. macrocarpus, frequently escapes to roadsides, and hybrids between the two subspecies are not uncommon (Heiser, 1949, 1954). Helianthus Bolanderi, on the other hand, is a native, endemic species, its natural range extending from southern Oregon to south central California. It consists of two races, one of which is found in the inner coast ranges and Sierra foothills, chiefly on serpentine soil; the other is a ruderal plant which replaces or occurs with H. annuus subsp. lenticularis, in the western part of the Sacramento Valley, particularly in Solano, Yolo, and Colusa counties. Heiser (1949) made artificial hybrids between H. annuus and H. Bolanderi, and compared them directly with the natural hybrid swarms. He found that the F1 hybrids had variable pollen and seed fertility, ranging mostly between 2 and 10 per cent. Meiosis in them is somewhat irregular, with chains of 6 chromosomes being usually found and chains of 8 occasionally. The two species differ, therefore, by several reciprocal translocations. Plants of backcross progenies have fertility values ranging from as low as the F1 hybrids to as high as the parental species. 1 Part of this study was carried out at Brookhaven National Laboratory under the auspices of the U. S. Atomic Energy Commission. 2 Present address: Department of Biological Sciences, San Fernando Valley State College, Northridge, California.

Chromosome Numbers of Four Species of the Genus Dendrocoelum Œrsted (Turbellaria tricladida paludicola)

CYTOTAXONOMICAL studies have been made on four species of planarians referred to the genus Dendrocoelum, namely, D. album (Steinmann), D. infernale (Steinmann), D. lacteum (O. F. Muller) and D. tubuliferum (De Beauchamp). The first and the last species were collected in Yugoslavia; D. infernale came from the locality in Switzerland reported by Aeppli1, while the material of D. lacteum originated from Austria, Denmark, Germany, Sweden, Switzerland, and Wales.

HYBRIDIZATION IN SOME SPECIES OF PTERIS L.

Pteris L. is an almost exclusively tropical genus of ferns of some 280 species (Copeland, 1947), many of which are distinctive and somewhat isolated. Also included in the genus, however, are several complexes containing from a few to many species. These present great taxonomic difficulties and the interrelationships of the components can often only be deduced by experimental methods. One such complex is centered on P. quadriaurita Retz. and the present paper deals with the behavior in Ceylon of three species of this group. Cytotaxonomic studies carried out over the last five years (Walker, 1956; Walker, publication pending) have shown that this complex contains many separate species which are superficially very much alike. Differences nevertheless exist in such fundamental characters as the level of polyploidy, type of breeding system, features of the spores and details of the juvenile plants. These differences, once determined by experimental methods, can then be correlated with relatively small but constant features on dried specimens, enabling species to be recognized in herbaria with, at most, the aid of a pocket lens. At least seven species of the P. quadriaurita complex are to be found growing in Ceylon, including P. quadriaurita Retz. sensu stricto itself. Several are ecologically or genetically isolated from one another and remain distinct in nature, but the three to be discussed below have hybridized freely resulting in the formation of very conspicuous hybrid swarms. Such hybrid swarms may continue to segregate and back-cross or, under certain circumstances, may become stabilized as a result of the sexual breeding system being replaced by apogamy. A complex situation of this nature has led to taxonomic difficulties even greater than those already inherent in the group as a whole.

A Cyto-Taxonomic Study of Setaria macrostachya (Gramineae) and Its Relatives in the Southwestern United States and Mexico

A Cyto-Taxonomic Study of Setaria macrostachya (Gramineae) and Its Relatives in the Southwestern United States and Mexico

Cytotaxonomic studies on the Gold Coast species of the genus Commelina Linn.

Journal Article Cytotaxonomic studies on the Gold Coast species of the genus Commelina Linn. Get access J. K. Morton, Ph.D. J. K. Morton, Ph.D. 1Lecturer in Botany, University College of the Gold Coast, Aehimota, Gold Coast Search for other works by this author on: Oxford Academic Google Scholar Botanical Journal of the Linnean Society, Volume 55, Issue 361, September 1956, Pages 507–531, https://doi.org/10.1111/j.1095-8339.1956.tb00021.x Published: 23 December 2008 Article history Received: 19 January 1956 Accepted: 28 June 2008 Published: 23 December 2008

Cytotaxonomic Studies in Allium

Cytotaxonomic Studies in Allium Cytotaxonomic Studies in Allium. I. The Allium Canadense Alliance. Ownbey Marion Aase Hannah C.. 106 pgs., illus. Monograph Supplement No. 1, Research Studies of the State College of Washington, Pullman, Wash. ( 1955) $2.00 AIBS Bulletin, Volume 6, Issue 2, April 1956, Page 34, https://doi.org/10.1093/aibsbulletin/6.2.34-d Published: 01 April 1956

Interspecific Hybrids and the Cytogenetics and Cytotaxonomy of Euallomyces

SUMMARYThis paper presents a report of genetic, cytogenetic, and cytotaxonomic studies made with the aquatic fungus Allomyces over the past seventeen years. Because there have not, hitherto, been a...

Cytotaxonomical evaluation of corresponding taxa

1) Corresponding taxa are known to include two kinds of plants, true vicariads, which have penetrated into a new area and later become differentiated, and false vicariads or substitution taxa, which have differentiated prior to their occupation of new areas. It is pointed out that although this geobotanical definition does not fully agree with the present grouping of species into gradual-species and abrupt-species, the latter never are vicarious, while perhaps the majority of the former are true vicariads. 2) By aid of cytotaxonomical studies it is shown that, within all groups of corresponding taxa, vicarious as well as substitution types are met with. This is shown to be true at the initial stage of habitat separation in the same region, in montane localities as compared with lowland habitats, as well as in regions separated by other physiographic and historical barriers. 3) A number of corresponding types from North America and Europe are compared from this point of view. It is demonstrated that while 92 pairs of taxa are truly vicarious in both regions, as many as 41 pairs are substitution species, differing in the number of chromosomes. A number of insufficiently known pairs are also listed. 4) It is pointed out that while cytotaxonomy might be of great help to geobotany in separating groups of different significance, these two branches of botany connected with modern taxonomy are in urgent need of much closer cooperation in order to solve many problems of evolutionary importance.

APOMIXIS IN PANICUM MAXIMUM

American Journal of BotanyVolume 41, Issue 1 p. 5-11 Article APOMIXIS IN PANICUM MAXIMUM H. E. Warmke, H. E. Warmke Office of Experiment Stations, Federal Experimental Station, Mayagüez, Puerto RicoSearch for more papers by this author H. E. Warmke, H. E. Warmke Office of Experiment Stations, Federal Experimental Station, Mayagüez, Puerto RicoSearch for more papers by this author First published: 01 January 1954 https://doi.org/10.1002/j.1537-2197.1954.tb14297.xCitations: 44AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume41, Issue1January 1954Pages 5-11 RelatedInformation

A Cytotaxonomic Study in the Genus Eupatorium

A Cytotaxonomic Study in the Genus Eupatorium

A Cytotaxonomic Study in the Genus Andropogon

American Journal of BotanyVolume 40, Issue 5 p. 297-306 Article A CYTOTAXONOMIC STUDY IN THE GENUS ANDROPOGON Frank W. Gould, Frank W. Gould Range and Forestry Department, Agricultural and Mechanical College of Texas, College Station, TexasSearch for more papers by this author Frank W. Gould, Frank W. Gould Range and Forestry Department, Agricultural and Mechanical College of Texas, College Station, TexasSearch for more papers by this author First published: 01 May 1953 https://doi.org/10.1002/j.1537-2197.1953.tb06483.xCitations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume40, Issue5May 1953Pages 297-306 RelatedInformation

A cytotaxonomic study of the genus Disporum in North America

A cytotaxonomic study of the genus Disporum in North America

CYTOTAXONOMIC STUDIES IN THE LOGANIACEAE. II. EMBRYOLOGY OF POLYPREMUM PROCUMBENS L

American Journal of BotanyVolume 35, Issue 7 p. 404-410 Article CYTOTAXONOMIC STUDIES IN THE LOGANIACEAE. II. EMBRYOLOGY OF POLYPREMUM PROCUMBENS L Raymond J. Moore, Raymond J. Moore Division of Botany and Plant Pathology, Central Experiment Farm, Ottawa, CanadaSearch for more papers by this author Raymond J. Moore, Raymond J. Moore Division of Botany and Plant Pathology, Central Experiment Farm, Ottawa, CanadaSearch for more papers by this author First published: 01 July 1948 https://doi.org/10.1002/j.1537-2197.1948.tb08099.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume35, Issue7July 1948Pages 404-410 RelatedInformation