STUDIES ON SOLIDAGO L.: IV. THE CHROMOSOME NUMBERS OF CERTAIN TAXA OF THE GENUS SOLIDAGO

1959 ◽  
Vol 37 (2) ◽  
pp. 209-228 ◽  
Author(s):  
Jean R. Beaudry ◽  
Denise L. Chabot
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Geographical Distribution ◽  
Chromosome Numbers ◽  
Morphological Characters ◽  
Basic Number ◽  
Western North America

The authors report the chromosome numbers of 25 taxa of the genus Solidago which had not yet been studied from this standpoint, and review the literature. The chromosome numbers of 42 taxa have now been published. The basic number of the genus is nine. Thirty-three taxa are diploid (2n = 18), five are tetraploid (2n = 36), three are aggregate taxa containing both diploid and tetraploid cytodemes, and one is hexaploid (2n = 54). Polyploidy has thus contributed to the evolution of the genus Solidago but it seems that most of the species have differentiated gradually. S. decemflora DC. of western North America differs from S. nemoralis Ait. of the same continent by morphological characters, its geographical distribution, and its chromosome number, the first taxon being tetraploid and the second diploid; the two are thus good species and not only varieties of the same species. The S. rigida of authors is an aggregate made up of two entities which are distinguished not only by their morphology and geographical distribution but also by their chromosome numbers; the eastern one (S. rigida L.) is tetraploid, whereas the western one (S. parvirigida Beaudry) is diploid. The bog and marsh goldenrods, S. Purshii and S. uliginosa, also possess different chromosome numbers, the first being diploid and the second tetraploid.

ÉTUDES SUR LE GENRE SOLIDAGO L. : II. LA MISE EN ÉVIDENCE DE LA POLYPLOÏDIE ENDOTAXONIQUE CHEZ S. PURSHII PORTER ET LES TAXA SIMILAIRES

1958 ◽  
Vol 36 (5) ◽  
pp. 663-670 ◽  
Author(s):  
Jean R. Beaudry ◽  
Alexis Zinger ◽  
Jacques Saint-Pierre
Keyword(s):  
Chromosome Number ◽  
Geographical Distribution ◽  
Chromosome Numbers ◽  
Guard Cells ◽  
Morphological Characters ◽  
The Other ◽  
Herbarium Specimens ◽  
Positive Correlation ◽  
Rapid Technique

In Solidago Purshii Porter, there are two cytodemes, one diploid (2n = 18) and the other tetraploid (2n = 36), which can be distinguished on the basis of the length of the guard cells of their leaf stomata. The diploid plants possess guard cells which are smaller than those of the tetraploid. These two entities of S. Purshii thus belong to the groups of cytodemes in which there exists a positive correlation between the chromosome numbers and the dimensions of certain quantitative morphological characters, such as the length of the guard cells.In groups in which the variation curves of the characters of the different cytodemes overlap little or not, the geographical distribution of the different cytodemes of the complex may be studied much more easily, rapidly, and comprehensively by measuring the length of the guard cells of herbarium specimens than by making chromosome number determinations. The data presented indicate that when sampling is made under the conditions described in this paper, determinations of the length of two guard cells of stomata of one mid-leaf per individual, made on two individuals per colony, is satisfactory for that purpose, on the average. However, it is recommended, as a safeguard, to increase these figures by a few units, and to make always a few direct chromosome number determinations to check the accuracy of this rapid technique. These direct determinations may also be necessary to know the chromosome numbers of certain extreme individuals of the different cytodemes which have guard cells that differ little in length.

Chromosome Numbers in Some Cacti of Western North America-VIII

Haseltonia ◽  
2009 ◽  
Vol 15 ◽  
pp. 117-134 ◽  
Author(s):  
Marc A Baker ◽  
Jon P Rebman ◽  
Bruce D Parfitt ◽  
Donald J Pinkava ◽  
Allan D Zimmerman
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Western North America

Chromosome Numbers in Some Cacti of Western North America-III

1977 ◽  
Vol 104 (2) ◽  
pp. 105 ◽  
Author(s):  
Donald J. Pinkava ◽  
Lyle A. McGill ◽  
Timothy Reeves
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Western North America

Cytotaxonomic studies of Draba species of Canada and Alaska: D. ventosa, D. ruaxes, and D. paysonii

1971 ◽  
Vol 49 (8) ◽  
pp. 1455-1460 ◽  
Author(s):  
Gerald A. Mulligan
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Related Species ◽  
Basic Chromosome Number ◽  
Base Number ◽  
Western North America ◽  
Closely Related Species ◽  
Basic Chromosome ◽  
Hexaploid Species

The cytotaxonomy of three closely related species of Draba, of the mountains of western North America, is discussed and a key is given: D. ventosa A. Gray (2n = 36), D. ruaxes Payson & St. John (2n = ca. 72), and D. paysonii Macbride (2n = 42). Evidence is presented demonstrating that D. ventosa and D. paysonii are triploids reproducing by agamospermy whereas the hexaploid species D. ruaxes is a sexual outcrosser. The former two species produce seed apomictically without any pollen stimulation. Draba ventosa and D. ruaxes have the basic chromosome number x = 12 and D. paysonii has the base number x = 14.

scholarly journals Estudios citogenéticos de dos especies y una variedad del género Nyctocereus (Cactaceae)

2017 ◽  
pp. 75
Author(s):  
Guadalupe Palomino-Hasbach ◽  
Socorro Zuleta-Lechuga ◽  
Leia Scheinvar
Keyword(s):  
Chromosome Number ◽  
Central America ◽  
Chromosome Numbers ◽  
Basic Number ◽  
Diploid Chromosome Number

The genus Nyctocereus (Cactaceae) consists of seven species and two varieties distributed from Mexico to Central America. They are valued as ornamental and for its edible fruits. In this study the chromosome numbers were determined and the karyotypes elaborated for N. castellanossi, N. serpentinus and N. serpentinus var. splendens. The diploid chromosome number for the three taxa was 2n = 22 and the karyotypes were very homogenous. No polyploids were detected. The basic number is x= 11. All the chromosomes in N. castellanosii and N. serpentinus were metacentric, while in N. serpentinus var. splendens two pairs of submetacentric chromosomes were observed. The total chromatin length was different for the three species, finding the lowest value in N. serpentinus var. splendens.

Lampetra richardsoni, a New Nonparasitic Species of Lamprey (Petromyzonidae) from Western North America

1965 ◽  
Vol 22 (1) ◽  
pp. 139-158 ◽  
Author(s):  
Vadim D. Vladykov ◽  
W. I. Follett
Keyword(s):  
British Columbia ◽  
North America ◽  
Geographical Distribution ◽  
Western North America ◽  
Body Proportions ◽  
Brook Lamprey ◽  
Lampetra Planeri

A new nonparasitic species of Petromyzonidae, Lampetra richardsoni, the western brook lamprey, from streams of British Columbia, Washington, Oregon, and possibly Alaska, is described and illustrated. This species is distinguished from Lampetra planeri (Bloch), the European brook lamprey (with which it has long been regarded as identical), by dentition, body proportions, pigmentation of the head and tail, and geographical distribution. The description is based on an examination of 275 specimens (69 transformed individuals and 206 ammocoetes).

CYTOGEOGRAPHY AND EVOLUTION OF THE DESGHAMPSIA CAESPITOSA COMPLEX

1963 ◽  
Vol 41 (5) ◽  
pp. 719-742 ◽  
Author(s):  
Shoichi Kawano
Keyword(s):  
Chromosome Number ◽  
Geographical Distribution ◽  
Morphological Variation ◽  
Phylogenetic Relationships ◽  
Basic Number ◽  
Basic Chromosome Number ◽  
Basic Form ◽  
Basic Chromosome ◽  
High Chromosome Number ◽  
Deschampsia Caespitosa

The chromosome number, karyotype, and morphological variation of plants of the Deschampsia caespitosa complex are reported in this paper. It is shown that the chromosome number of 2n = 26 is most common in typical D. caespitosa (L.) Beauv. But, remembering the basic chromosome number in the Agrostideae, the original basic number of the genus Deschampsia is considered to be x = 7. Thus, a reduction of the chromosome number from 28 to 26 is speculated in this particular group of Deschampsia. The plant from Mt. Albert, Canada, referable to D. caespitosa ssp. littoralis (Reut.) Rchb., has a high chromosome number of 2n = 49. Considering the morphological affinity between D. caespitosa ssp. littoralis and D. alpina Roem. & Schult., as well as their geographical distribution, parallel development of the plants with such high irregular chromosome number is assumed.The karyotype of D. caespitosa s. str. was also investigated. This species has a highly specialized asymmetrical karyotype, viz., K(2n) = 26 = 4 V + 10 J + 12 I.On the basis of cytology, morphology, ecology, and geographical distribution, the phylogenetic relationships within this complex were considered. The littoralis type, having well-developed panicles, large spikelets, three (rarely four) florets, and a preference for wet terrestrial sites, is speculated to be the most basic form in the D. caespitosa complex, even though the type with smaller spikelets, i.e., caespitosa s. str. is at the present time much more abundant. Various other population groups such as D. caespitosa v. parviflora (Thuill.) Coss. & Germ., D. brevifolia R. Br., D. alpina Roem. & Schult., and the species of the bottnica group (including D. beringensis Hultén, D. bottnica (Wahlenb.) Trin., D. congestiformis Booth, D. holciformis F. & C. Presl, D. mackenzieana Raup, D. macrothyrsa Tatewaki et Ohwi, D. obensis Roshev., and D. wibeliana Schur.) are presumed to be more specialized.

A clarification of the chromosome number situation in Sanguisorba canadensis

1973 ◽  
Vol 51 (11) ◽  
pp. 2075-2077
Author(s):  
Gerald A. Mulligan ◽  
William J. Cody
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Western North America

Although eastern North American populations of Sanguisorba canadensis L. are reported to be octoploid and plants of western North America reported to be tetraploid, it was found that this species is usually tetraploid, 2n = 28, throughout its range. No octoploids were found among the plants studied, even in material from the locations where octoploids have been reported to occur.

Two New Asian Xanthoria Species (Teloschistaceae, Lichenized Ascomycotina)

1997 ◽  
Vol 29 (2) ◽  
pp. 173-190 ◽  
Author(s):  
S. Kondratyuk ◽  
J. Poelt
Keyword(s):  
North America ◽  
Far East ◽  
Morphological Characters ◽  
Western North America ◽  
Species Pair ◽  
Typical Species

AbstractTwo corticolous species of the lichen genus Xanthoria, X. alfredi S. Kondratyuk & Poelt from Russian and Chinese Far East and X. aphrodites Kalb, Poelt & S. Kondratyuk from Cyprus are described. Morphological characters, in particular the presence of true rhizines within Xanthoria and their differences from hapters are indicated. Xanthoria novozelandica Hillmann is the first species of Xanthoria in which oil paraphyses have been found. A key to the treated species, including X. novozelandica and Xanthoria sp. from western North America is provided. The ecology and distribution of described species are discussed. Xanthoria alfredi and X. ulophyllodes probably constitute a typical species pair; X. alfredi and X. aphrodites are relict endemics.

Didymascella thujina. [Descriptions of Fungi and Bacteria].

1997 ◽  
Author(s):  
D. W. Minter
Keyword(s):  
North America ◽  
New Brunswick ◽  
Geographical Distribution ◽  
Prince Edward Island ◽  
Western North America ◽  
Planted Forests ◽  
Thuja Occidentalis ◽  
Introduced Plants ◽  
Resistant Varieties ◽  
Natural Stands

Abstract A description is provided for Didymascella thujina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: 'Keithia disease' or 'cedar leaf blight'. HOSTS: Leaves of Thuja occidentalis, T. plicata. Occurring on T. plicata throughout its range in western North America, and widespread in North America on T. occidentalis, apparently confined to these two hosts, fide Pawsey (1958). GEOGRAPHICAL DISTRIBUTION: Austria, Belgium, Canada (Alberta, British Columbia, New Brunswick, Northwest Territories, Ontario, Prince Edward Island, Quebec), Denmark, Eire, Netherlands, Norway, UK (England, Scotland, Wales), USA (Alaska, Idaho, Oregon, Vermont, Washington, Wisconsin). Unsuccessful searches on introduced plants in Chile and Ukraine. With the introduction of resistant varieties of its host, this fungus is becoming less common in planted forests and on hedge trees, though it is still generally abundant in natural stands of its hosts. TRANSMISSION: By air-borne ascospores in humid conditions.

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