Chromosome numbers from pollen in some North American Impatiens (Balsaminaceae)

1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Present Survey ◽  
The One ◽  
Basic Numbers

Chromosome counts for eight species of Impatiens from North American populations have been determined from herbarium specimens. The chromosome number n = 10 for I. ecalcarata Blank, is a new report. It is apparent from the present survey that there are at least three basic numbers (n = 7, 10, and 13) represented in North America as opposed to the one (n = 10) suggested by the earlier workers.

The annual species of stinging nettle (Hesperocnide and Urtica) in North America

1976 ◽  
Vol 54 (3-4) ◽  
pp. 374-383 ◽  
Author(s):  
D. W. Woodland ◽  
I.J. Bassett ◽  
C. W. Crompton
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Chromosome Numbers ◽  
Annual Species ◽  
Chromosome Counts ◽  
Stinging Nettle ◽  
The One ◽  
North America North

Descriptions (including those of pollen), distributional data, and chromosome counts are given for one species of Hesperocnide and three annual species of Urtica (stinging nettles) in North America north of Mexico: Hesperocnide tenella, Urtica chamaedryoides, U. gracilenta, and U. urens. Hesperocnide tenella has a chromosome number of 2n = 24 while all three Urtica spp. have the same chromosome number of 2n = 26. All reported chromosome numbers are new except the one for U. urens. A key which separates the taxa that are studied is provided and synonyms that are applied to the species are discussed.

Chromosome numbers of 15 North American bumble bee species (Hymenoptera, Apidae, Bombini)

1983 ◽  
Vol 25 (1) ◽  
pp. 26-29
Author(s):  
Robin E. Owen
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Morphological Divergence ◽  
Chromosome Counts ◽  
Monophyletic Origin ◽  
The Social

Chromosome counts were obtained for 14 Bombus Latr. species (the social bumble bees) belonging to four subgenera and for one Psithyrus Lep. species (the social parasitic bumble bees). In Bombus the haploid numbers were consistent within each subgenus and there was variation between subgenera; the subgenera Bombus s.s. and Pyrobombus have n = 18, while Separatobombus and Cullumanobombus have n = 19. Thus considerable morphological divergence between subgenera is often, but not always, paralleled by divergence in chromosome number. Psithyrus ashtoni has n = 25, higher than all Bombus species yet examined. This provides support for the monophyletic origin of Psithyrus, but the high n is not expected if eusociality selects for increase in chromosome number.

The chromosome numbers of five North American and European leech species

1987 ◽  
Vol 65 (3) ◽  
pp. 681-684 ◽  
Author(s):  
Ronald W. Davies ◽  
R. N. Singhal
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Chromosome Evolution ◽  
Chromosome Counts ◽  
Prophase I ◽  
Metaphase I

Chromosome counts were obtained for four glossiphoniid species belonging to three genera (Glossiphonia, Theromyzon, Placobdella) and for one erpobdellid species (Dina lineata) of freshwater leeches. Theromyzon rude, which has a Palaearctic distribution, had seven bivalents at prophase I and metaphase I, while the Holarctic T. tessulatum had eight bivalents, giving diploid chromosome numbers of 14 and 16, respectively. Placobdella papillifera from Alberta had a chromosome number of 2n = 24 and Glossiphonia complanata from Alberta and England had chromosome counts of 2n = 28. At prophase I and metaphase I nine bivalents occurred in the majority of the nuclei of Dina lineata. These findings are discussed in relation to the chromosome evolution and phylogenetic schemes proposed by previous authors.

Circaea × intermedia in eastern North America with particular reference to Ontario

1977 ◽  
Vol 55 (23) ◽  
pp. 2919-2935 ◽  
Author(s):  
Erich Haber
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Somatic Chromosome ◽  
Parental Species ◽  
Eastern North America ◽  
Chromosome Counts ◽  
Morphological Differences ◽  
Somatic Chromosome Numbers

Circaea × intermedia Ehrh. in North America is an interspecific hybrid between C. alpina L. and C. lutetiana L. subsp. canadensis Aschers. & Magnus. In spite of the morphological differences that exist between the European and North American subspecies of C. lutetiana, hybrids from both continents are morphologically identical. Documentation of the intermediacy of the hybrid taxon is presented based on the evaluation of the means of 22 characters of specimens from an Ontario locality at which all three taxa are found.Diploid chromosome counts of 2n = 22 are reported for Ontario populations of the hybrid and parental species. The presence of irregular, somatic chromosome numbers are also reported for all three taxa.Distribution maps for all three taxa in eastern North America are included. In the case of C. lutetiana subsp. canadensis, the northern range is sharply delimited by the Precambrian–Paleozoic bedrock boundary.A table of character comparisons and a key to the three taxa summarizes the salient characteristics of the hybrid and the parental species in eastern North America.

Chromosome numbers and the taxonomy of North American Agalinis (Scrophulariaceae)

1984 ◽  
Vol 62 (3) ◽  
pp. 454-456 ◽  
Author(s):  
Judith M. Canne
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Base Number ◽  
Chromosome Counts ◽  
Base Chromosome Number ◽  
First Time

Chromosome counts are provided for 25 populations representing 18 species of Agalinis Raf. Chromosome numbers are reported for the first time for A. pinetorum, A. laxa, A. acuta, A. gattingeri, and A. skinneriana. The base chromosome number for section Linifoliae, section Heterophyllae, section Purpureae subsections Purpureae and Setaceae, and section Tenuifoliae is established at x = 14. Section Erectae and section Purpureae subsection Pedunculares have a base number of x = 13.

TAXONOMY OF PLANTAGO L. IN NORTH AMERICA: SECTIONS HOLOPSYLLIUM PILGER, PALAEOPSYLLIUM PILGER, AND LAMPROSANTHA DECNE.

1967 ◽  
Vol 45 (5) ◽  
pp. 565-577 ◽  
Author(s):  
I. J. Bassett
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
North American ◽  
Chromosome Numbers ◽  
Native North American ◽  
Considerable Confusion ◽  
The One

The taxonomy, chromosome numbers, distribution, and notes on phytogeography of the one introduced and the six native North American Plantago species in sections Holopsyllium Pilger, Palaeopsyllium Pilger, and Lamprosantha Decne. are presented. Although there has been considerable confusion among the species Plantago eriopoda Torr., P. tweedyi Gray, and P. canescens Adams, this investigation demonstrates that they can be readily separated and that each has a distinctive geographical distribution. Plantago macrocarpa Cham. & Schlecht., P. cordata Lam., P. eriopoda Torr., P. tweedyi Gray, P. sparsiflora Michx., and P. media L. were found to have 24 somatic chromosomes and P. canescens Adams, 12.

Can morphology and chromosome number contribute to species delimitation? A case in the Hibiscus trionum complex (Tribe Hibisceae, Malvaceae)

Phytotaxa ◽  
2019 ◽  
Vol 416 (4) ◽  
pp. 278-286
Author(s):  
MOHAMED OWIS BADRY ◽  
JENNIFER A. TATE ◽  
PRASHANT JOSHI ◽  
AHMED MAHMOUD ABBAS ◽  
SOHAIR THABET HAMED ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Species Delimitation ◽  
Taxonomic Revision ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Comprehensive Description ◽  
Hibiscus Trionum ◽  
The World ◽  
First Time

A taxonomic revision of Hibiscus trionum from Egypt was undertaken using morphological and cytological studies of field collections and herbarium specimens. The data indicate that all specimens so far collected in Egypt belong to H. tridactylites, rather than H. trionum. This paper includes a comprehensive description of H. tridactylites, its occurrence, a comparison with other species in the H. trionum complex, and comments on habitat, along with images for easy identification. In addition, chromosome counts for this species from Egypt have been determined for the first time, which add to existing information on chromosome counts for the species from different regions of the world.

Chromosome numbers and sexual compatibility in North America of Rorippa sylvestris (Cruciferae)

1984 ◽  
Vol 62 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Gerald A. Mulligan ◽  
Derek B. Munro
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Field Observations ◽  
Sexual Compatibility ◽  
Intraspecific Crossing

Tetraploid (2n = 32), pentaploid (2n = 40), and hexaploid (2n = 48) plants of Rorippa sylvestris (L.) Besser (Cruciferae) and a natural pentaploid (2n = 40) interspecific hybrid, R. sylvestris × R. palustris (L.) Besser, are recorded for North America. These counts are compared with published information on European plants. Tetraploids are most common in Europe (68 vs. 20%), whereas hexaploids are most common in North America (65 vs. 29%). Although self-incompatible R. sylvestris rarely sets seed in nature, indicating that plants within most sites are genetically the same clone, intraspecific crossing data, chromosome information, and field observations indicate that North American R. sylvestris results from the vegetative introduction of many different genotypes.

Taxonomic studies on the genus Atrichum in North America

1969 ◽  
Vol 47 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Robert R. Ireland
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
Distinct Species ◽  
The United States ◽  
Morphological Characters ◽  
Taxonomic Study ◽  
Chromosome Counts ◽  
The Status ◽  
Taxonomic Studies

A taxonomic study was made of several North American taxa in the genus Atrichum. The primary emphasis was on the Canadian taxa and a key to the six species (A. altecristatum, A. angustatum, A. crispum, A. oerstedianum, A. selwynii, A. undulatum) and one variety (A. undulatum var. gracilisetum) of the country is presented. Atrichum oerstedianum, which has been confused with A. undulatum, is added to the moss flora of the United States and Canada. The distribution of A. crispum is clarified and a detailed study of the species revealed new morphological characters that are useful to distinguish it. A variety of A. undulatum, the var. altecristatum, is raised to the rank of a species and morphological and distributional data are given to support the status of A. selwynii as a distinct species. The first chromosome counts are reported for A. selwynii (n = 7) and A. altecristatum (n = 14). Detailed descriptions are provided for A. altecristatum, A. crispum, A. oerstedianum, and A. selwynii.

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.

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