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

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.

1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill

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.


1983 ◽  
Vol 25 (1) ◽  
pp. 26-29
Author(s):  
Robin E. Owen

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.


1987 ◽  
Vol 65 (3) ◽  
pp. 681-684 ◽  
Author(s):  
Ronald W. Davies ◽  
R. N. Singhal

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.


1959 ◽  
Vol 37 (2) ◽  
pp. 209-228 ◽  
Author(s):  
Jean R. Beaudry ◽  
Denise L. Chabot

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.


1960 ◽  
Vol 38 (3) ◽  
pp. 381-386 ◽  
Author(s):  
F. H. Montgomery ◽  
Shung-Jun Yang

The literature relating to the chromosome numbers in the genus Erigeron has been reviewed, and all reported numbers are given. The chromosome number for E. breweri var. porphyreticus (Jones) Cronquist, 2n = 18; E. divergens var. cinereus A. Gray, 2n = 27; E. glabellus var. glabellus Cronquist, 2n = 36; E. glabellus var. pubescens (Hook.) Cronquist, 2n = 36; E. hyssopifolius Michx., 2n = 18; E. quercifolia Lam., 2n = 36; E. simplex Greene, 2n = 27; E. strigosus var. beyrichii (Fisch. & Mey.) A. Gray, 2n = 27; and E. vernus T. & G., 2n = 18 are new determinations. Different numbers from those previously reported have been found for E. pulchellus Michx., 2n = 27, and E. strigosus (Muhl.) Willd., 2n = 36. Chromosome counts over a large area of their distribution have been made for E. annuus (L.) Pers., E. pulchellus Michx., E. philadelphicus L., and E. strigosus (Muhl.) Willd.


2021 ◽  
Vol 45 (2) ◽  
pp. 333-339
Author(s):  
Seyed Ghaffari ◽  
Abbas Zare ◽  
Fereshteh Corom ◽  
Masoureh Sedaghati

Original meiotic or both meiotic and mitotic chromosome numbers are reported for ten endemic and one non endemic species in nine vascular plant families from Iran. The chromosome numbers of Acantholimon schahrudicum, A. truncatum, Anthochlamys multinervis, Campanula perpusilla, Cousinia calcitrapa var. interrupta, Dorema ammoniacum, Euphorbia gedrosiaca, and Hyocyamus orthocarpus were determined for the first time. The chromosome counts for Astrodaucus persicus and Hedysarum criniferum agree with previous ones. The gametic chromosome numbers for Hedysarum criniferum and Allium stipitatum are reported here for the first time. The occurrence of accessory chromosomes are also reported for Acantholimon schahrudicum and Dorema ammoniacum, being the first records of B chromosomes in the genera Acantholimon and Dorema.


2018 ◽  
Vol 19 (6) ◽  
pp. 2118-2126
Author(s):  
TITIEN NGATINEM PRAPTOSUWIRYO ◽  
MUGI MUMPUNI

Praptosuwiryo TNg, Mumpuni M. 2018. Chromosome numbers of some species of Pteris (Pteridaceae) in Java, Indonesia. Biodiversitas 19: 2118-2126. Pteris L. (Pteridaceae) is a large fern genus consisting of about 250 species which distributed predominantly in tropical and subtropical countries. The genus grows in a diversity of ecosystems, either terrestrially or lithophytically, although most species occur in the forest. A study of the cytology of Pteris in Java is being undertaken for the conceptual understanding of the interrelationships between various fern species in the Malesian region. This aims of our study are: (1) to observe somatic chromosome number of some species of Pteris in Java; (2) to determine the reproduction types of the observed species by counting the spore number per sporangium; (3) to discuss polyploidy in the species in relation to plant morphological variation across their geographical distribution. Chromosome counts for eight species are reported. Pteris biaurita is an apogamous diploid species (2n = 58). Pteris ensiformis var. ensiformis has chromosome numbers of 2n = 87 (apogamous triploid) and 2n = 116 (sexual tetraploid), while                 P. ensiformis var. victoriae has a chromosome number 2n = 58 and is a sexual diploid. Pteris fauriei is an apogamous triploid species (2n = 87). Pteris longipinnula has a chromosome number of 2n = 116 (tetraploid). Pteris multifida and P. vittata are sexual tetraploids (2n=116). Pteris tripartita has two ploidy levels (sexual diploid and tetraploid). Another currently unplaced Javanese Pteris sp. has 2n = 87 (apogamous triploid). Diploid P. biaurita, tetraploid P. ensiformis, triploid P. fauriei, diploid P. tripartita, and teraploid P. vittata are new record cytotypes for Central Java. Polyploidy in the genus in relation to plant morphological variation across its geographical range is discussed.


HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 567-570 ◽  
Author(s):  
Ryan N. Contreras ◽  
John M. Ruter

Genome size estimates and chromosome number information can be useful for studying the evolution or taxonomy of a group and also can be useful for plant breeders in predicting cross-compatibility. Callicarpa L. is a group of ≈140 species with nearly worldwide distribution. There are no estimates of genome size in the literature and the information on chromosome numbers is limited. Genome size estimates based on flow cytometry are reported here for 16 accessions of Callicarpa comprising 14 species in addition to chromosome counts on six species. Chromosome counts were conducted by staining meristematic cells of roots tips using modified carbol fuchsin. Holoploid genome size estimates ranged from 1.34 pg to 3.48 pg with a mean of 1.74 pg. Two tetraploids (2n = 4x = 68; C. salicifolia P'ei & W. Z. Fang and C. macrophylla Vahl GEN09-0081) were identified based on holoploid genome size and confirmed by chromosome counts. There was little variation among species for monoploid genome size. 1Cx-values ranged from 0.67 pg to 0.88 pg with a mean of 0.77 pg. Chromosome counts for six species revealed a base chromosome number of x = 17. Callicarpa chejuensis Y. H. Chung & H. Kim, C. japonica Thunb. ‘Leucocarpa’, C. longissima Merr., and C. rubella Lindl. were confirmed as diploids (2n = 2x = 34). Cytology supported flow cytometry data that C. salicifolia and C. macrophylla GEN09-0081 were tetraploids. The two accessions of C. macrophylla included in the study were found to be of different ploidy levels. The presence of two ploidy levels among and within species indicates that polyploidization events have occurred in the genus.


1969 ◽  
Vol 47 (8) ◽  
pp. 1257-1275 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton

The morphology and chromosome number of nine species of Cirsium of eastern North America are considered. Chromosome counts are presented for the first time for C. iowense, 2n = 18; C. lecontei, 2n = 32; C. nuttallii, 2n = 24, 28; C. repandum, 2n = 30; C. smallii, 2n = 34; C. engelmannii, 2n = 20; C. texanum, 2n = 22, 24; C. virginianum, 2n = 28. Additional chromosomes, possibly to be considered as accessories, were found in C. nuttallii, C. engelmannii, and C. texanum. These chromosomes render uncertain the number characteristic of these species. A key to the 26 native and introduced species found in Canada and the United States east of 100° west latitude is presented. The interrelationships of the eastern species and of the species of the western series Undulata are discussed.


1963 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
HP Ramsay

Chromosome numbers have been determined for 19 genera and 53 species of Proteaceae in Australia. The chromosomes are small in all genera except Persoonia n = 7, Placospermum n = 7 (Johnson and Briggs 1963) and Bellendena n = 5 (Venkata Rao 1957), which have chromosomes comparable in size with those in the Liliaceae and Ranunculaceae. In other Australian genera chromosome numbers range from n = 14 (Cenarrhenes, Macadamia, Xylornelum, Lambertia, Banksia, Dryandra), n = 13 (Isopogon, Petrophile, Stirlingia, Adenanthos), n = 11 (Conospermum, Telopea, Lomatia, Stenocarpus) to n = 10 (Symphionema, Grevillea, Hakea). There are no genera counted so far in Australia with n = 12, a number common to many South African Proteaceae. Only one example of intrageneric polyploidy in the family is reported, for Persoonia toru A. Cunn. n = 14 by Hair and Beuzenberg (1959), while Venkata Rao (1957) discovered one example of intrageneric difference in number in two species of Orites with n = 14, 15, but in all other members of the family investigated, the chromosome numbers are constant for all species of the one genus, indeed for all the genera in certain tribes, e.g. Banksieae. Cytological evolution and distribution of the family have been discussed and a scheme representing possible chromosome number relationships drawn up.


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