Karyological studies in IberianSonchus (Asteraceae: Lactuceae): S. oleraceus, S. microcephalus andS. asper and a general discussion

Chromosome numbers and karyotypes ofSonchus oleraceus (n=16, 2n=32),S. asper (n=9, 2n=18 for subsp.asper and subsp.glaucescens, andS. microcephalus (n=15, 2n=30) are studied; for the first time their idiograms are given. Karyotypes mainly comprise small chromosomes with a degree of asymmetry 2B inS. oleraceus andS. microcephalus and 2A or 2A-2B inS. asper. No karyological differences can be pointed out betweenS. asper subspecies. Data presented support the amphiploid character ofS. oleraceus, and the origin ofS. microcephalus through a dysploid process involving the former taxon. In Iberian representatives of the genus, diagrams of karyotype asymmetry indices show a cluster grouping for species, with the detached exceptions ofS. maritimus andS. crassifolius, which spontaneously hybridize in central Spain. A review of available karyological data shows that in the evolution of the genusSonchus s.l. and relatives, the basic chromosome number x=9 has generally been maintained. Dysploidy is restricted to the seriesS. bourgeaui (n=8) —S. tenerrimus (n=7) andS. oleraceus (n=16) —S. microcephalus (n=15), evolutionarily related and included in the present subgenusSonchus. Polyploidy has been detected in a total of nine taxa ofSonchus and in the generaEmbergeria, Kirkianella, andDendroseris, being more common in peripheral regions of the distribution area of the group. Five diversification centers are proposed for the whole group, of which the Western Mediterranean area, including the Iberian Peninsula, is related to diversification of the present subgenusSonchus.     

Chromosome numbers of Mongolian Angiosperms. II.

Chromosome numbers are reported for 20 collections of Mongolian plants representing 19 taxa. The first chromosome records are reported forArabidopsis mongolica (2n=16),Caragana pygmaea (2n=16),Isatis costata var.leiocarpa (2n=28),Lophanthus chinensis (2n=18) andStevenia cheiranthoides (2n=32). Counts partly differing from those previously recorded are given forBatrachium trichophyllum subsp.trichophyllum (2n=32+0-2B, 36+6B),Cuscuta chinensis (2n=60),Dracocephalum fragile (2n=72) andErysimum flavum (2n=14). Chromosome numbers of the following taxa were confirmed:Astragalus monophyllus (2n=16),Erodium stephanianum (2n=16),Gastrolychnis apetala (2n=24),Geum aleppicum (2n=42),Linum baicalense (2n=18),Rorippa palustris (2n=32),Rubia cordifolia subsp.pratensis (2n=22),Schizonepeta multifida (2n=12),Tribulus terrestris (2n=36) andVicia cracca (2n=14). Taxonomic remarks onArabidopsis mongolia, Erysimum flavum, Stevenia cheiranthoides andVicia cracca are added. A new combinationArabidopsis mongolica (Botsch.)Měsí?ek & Soják is proposed.     

Chromosome counts of some Cuban Angiosperms

Chromosome numbers are reported for 14 species collected in Cuba. The first chromosome records are reported forAlbizzia cubana Britton etWilson (2n=26),Atkinsia cubensis (Britton etWilson)Howard (2n=26),Caesalpinia violacea (Mill.)Standl. (2n=24),Colubrina ferruginosa Brongn. (2n=24). Chromosome numbers of the following species were confirmed:Albizzia lebbeck (L.)Benth. (2n=26),Canavalia maritima (Aubl.)Thouars (2n=22),Casuarina equisetifolia Forst. (2n=18),Cedrela mexicana M.J. Roem. (2n=56),Delonix regia (Bojer)Raf. (2n=28),Guazuma tomentosa H.B.K. (2n=16),Lysiloma bahamense Benth. (2n=26),L. latisiliqua (L.)Benth. (2n=26),Samanea saman (Jacq.)Merrill (2n=26),Thespesia populnea (L.)Soland (2n=26).     

Chromosome counts of some MongolianPotentilla species

Chromosome numbers are reported for 26 collections representing 12 MongolianPotentilla taxa. The first chromosome records are reported forP.[x]agrimonioides Bieb. (2n = 42, 49–50),P. [x]chionea Soják (2n = 64, 74+1B, 84–86, 86),P. [x]stepposa Soják (2n = 62) andP. supina, L. subsp.costata Soják (2n = 42). Tetraploid and pentaploid populations ofP. sericea L. (2n = 28, 34, 35) and hexaploid populations ofP. omithopoda Tausch (2n = 42) were found in Mongolia. Chromosome numbers of the following species were confirmed:P. longifolia Willd. exSchlecht. (2n = 14),P. multifida L. (2n = 28),P. sanguisorba Willd. exSchlecht. (2n = 28),P. sericea L. (2n = 42),P. supina L. subsp.paradoxa (Nutt.) Soják (2n = 28 China) andP. tanacetifolia Willd. exSchlecht. (2n = 28). Taxonomic observations are briefly discussed.     

Chromosome numbers of flowering plants from northern Norway and Svalbard

Chromosome numbers of 25 taxa of flowering plants from northern Norway and Svalbard are reported. Four species and one subspecies, Carex halophila F. Nyl. (2n = ca. 78), C. stenolepis Less. (2n = ca. 80), Salicorniapojarkovae N. Sem. (2n = 36), Alnus incano (L.) Moench ssp. kolaensis (Orlova) Love (2n = 28), and Saxifraga svalbardensis D. O. Øvstedal (2n = ca. 64), have not been studied karyologically before. Chromosome numbers of four additional species are reported for the first time from Norway; those of another six species for the first time from northern Norway. The hybrid Salix herbacea L. (2x) x 5. polaris Wahlenb. (6x) is proved tetraploid and may be fertile. A possible hybrid between Saxifraga hyperborea R. Br. and S. rivularis L. was revealed.     

Selected chromosome counts of the Czechoslovak flora I

Chromosome numbers of the following nine taxa of the Czechoslovak flora are given:Atriplex rosea L.,Cardamine resedifolia L.,Groenlandia densa (L.)Fourr.,Isoëtes lacustris L.,Lysimachia nemorum L.,Parnassia palustris L.,Phelipanche caesia (Rchb.) Soják,Rumex patientia L. subsp.patientia andSymphytum officinale L. s. str. A new chromosome number of 2n=80 is reported forRumex patientia L. subsp.patientia. Chromosome numbers of another five taxa are first reported from Czechoslovakia. Each of the ascertained chromosome counts is discussed with respect to hitherto known reports.     

Chromosome numbers of dominican compositae

Chromosome numbers of 34 species of Dominican Compositae in 26 genera and nine tribes are reported. First counts are given forCoreopsis buchii (2n = 64),Lagascea mollis (2n = 34),Spilanthes urens (n = 16),Liabum subacaule (n = 18),Eupatorium sciatraphes (2n = 40),Hieracium gronovii (2n = 18),Vernonia buxifolia (2n = 34),V. sprengeliana (2n = 34),V. racemosa (2n = 28), andChaptalia leiocarpa (2n = 48,ca. 58). Our report forNarvalina domingensis (2n = 120) is the first for any species of this genus.     

Chromosome numbers in Great Plains species of Penstemon (Scrophulariaceae)

Chromosome numbers are reported for 79 populations ofPenstemon representing 20 species. All but two species counted here are diploids. First counts are reported for seven taxa, all asn=8 or 2n=16.     

Karyology of theScorzonera (Compositae) species from the Iberian Peninsula

A karyological study of 15 taxa ofScorzonera L. from the Iberian Peninsula has been made. The chromosome numbers found inS. hispanica var.pinnatifida, S. baetica, S. reverchonii, S. angustifolia, S. laciniata var.calcitrapifolia and var.subulata (2n = 14) are new. Diploid cytotypes with 2n = 14 and 2n = 12 prevail, andS. hispanica var.crispatula is the only taxon which exhibits autopolyploidy (2n = 14, 28). x = 7 is considered to be the base chromosome number within the genus, with x = 6 being derived from it by translocation. This and detailed karyotype analyses allow to group the Iberian Peninsula species ofScorzonera into three groups.     

A biosystematic study on polyploid populations of the genusSpiraea (Rosaceae) in Korea

A total of 61 chromosome counts from 11 taxa of Korean Spiraea was made. Our counts are the first report for eight taxa;S. blumei (2n=18, 36),S. chartacea (2n=36),S. chinensis (2n=36),S. fritschiana (2n=27, 36),S. microgyna (2n=18),S. prunifolia var.simpliciflora (2n=18),S. pseudocrenata (2n=36), andS. trichocarpa (2n=18). A new chromosome number of 2n=36 (tetraploid) is reported forS. pubescence. Populations of three species includingS. blumei, S. pubescence and .V.fritschiana, show different ploidy levels; diploid and tetraploid populations are found in the former two species and triploid and tetraploid ones, in latter species. Multiplication of chromosome numbers contributes to increase in size of pollen and stomata in the three species. Populations with different ploidy levels inS. blumei occupy different regions; diploid populations in inland Korea and tetraploid ones in Ullung Island. Island tetraploid population of 5.blumei might be originated from intra-island polyploidization through the introduction of diploid from inland Korea, considering the worldwide distribution of this species. Pollen fertilities of island populations of ,S′.blumei are relatively low, and sometimes no pollen grain is produced in anther sacs; it suggests that tetraploid population of the island is gynodioecious which may serve reduction of inbreeding depression.     

Karyological and taxonomic notes on Cytisus Desf. Sect. Spartopsis Dumort. and Sect. Alburnoides DC. (Genisteae, Leguminosae) from the Iberian Peninsula and Morocco

Karyological information on Cytisus species indicates at least two chromosome numbers for most of the taxa. This instability is, a striking karyological feature of Cytisus . Chromosome numbers of taxa in Sect. Spartopsis and Sect. Alburnoides, both well represented in Morocco and the Iberian Peninsula, are presented here. We provide the first data on chromosome numbers for the Moroccan taxa: C. grandiflorus subsp. barbarus , and subsp. haplophyllus (n = 23, 2 n = 46) , C. maurus (2 n = 48), C. megalanthus ( n = 23), C. arboreus subsp. arboreus , subsp. baeticus , and subsp. catalaunicus (2 n = 50), C. valdesii ( n = 23 ). New populations from the Iberian Peninsula have been counted: C. grandiflorus subsp. grandiflorus (2 n = 46), C. scoparius subsp. scoparius ( n = 23) , C. striatus subsp. eriocarpus ( n = 23, 2 n = 46), C. multiflorus (n = 23), C. oromediterraneus ( n = 23, 24). Our data confirm the instability of the chromosome number in Cytisus . The presence of B chromosomes in C. valdesii and C. megalanthus , as well in other species, is discussed in relation to this instability and previous data. We suggest that instability of the chromosome number within a taxon, and even in the same population, may be related to the breakage of A chromosomes and the appearance of B chromosomes.     

Taxonomy of the bouteloua repens complex

An investigation was made of grasses variously referred toBouteloua americana,B. filiformis, B. radicosa, B. repens, B. bromoides, B. heterostega, B. pubescens, andB. williamsii. Four of these species,B. americana, B. williamsii, B. repens, andB. radicosa, are maintained as separate taxa; the other four are reduced to synonymy underB. repens. Described as new isB. longiseta, with a tropical distribution from Oaxaca, Mexico, south to Honduras. Chromosome counts of 2n = 20 forB. williamsii and 2n = 40 forB. longiseta are the first for these taxa. Counts of 2n = 20, 2n = 40, and 2n = 60, and a few aneuploid numbers, are reported forB. repens     

CHROMOSOME NUMBERS IN THE LEGUMINOSAE. III. SPECIES OF THE SOUTHWESTERN UNITED STATES AND MEXICO

Turner, B. L., and Olin S. Fearing. (U. Texas, Austin.) Chromosome numbers in the Leguminosae. III. Species of the Southwestern United States and Mexico. Amer. Jour. Bot. 47(7) : 603–608. Illus. 1960.—Chromosome counts for 43 species of the Leguminosae from the southwestern United States and Mexico have been reported. These include first reports for 42 taxa of which 16 are for the subfamily Mimosoideae. Olneya tesota (2n = 18) is the only new generic count listed. Chromosome reports of particular significance include a single polyploid count for a North American species of Acacia, as well as diploid and tetraploid counts for closely related taxa in this genus. Four species of the genus Schrankia were found to be diploid with In = 26, indicating a base of x = 13 instead of the x = 8 reported by some previous workers. Leucaena pulverulenta was found to have a diploid count of 2n = 56 indicating a base of x = 14.     

Chromosome numbers and taxonomic notes in the genus Nama (Hydrophyllaceae)

Chromosome numbers are reported for 48 collections representing 15 species and three varieties ofNama. Counts for 10 taxa are initial reports, all being diploid withn = 7. Diploid counts forN. jamaicense (n = 7), previously known only as tetraploid, are also reported. Comments on the taxonomic relationships of selected taxa are included.     

Diversity of Avenella Drejer (Gramineae) in the Iberian Peninsula inferred from micromorphology, cytogenetic analysis, isozyme assays and in situ hybridization

Micromorphology, cytogenetic analysis, isozyme assays, and in situ hybridization were used in order to analyse the diversity of Avenella in the norm-west Iberian Peninsula. Among the taxa analysed, somatic chromosome numbers 2 n = 4x = 28 and 2 n = 8x = 56 were found. Differences in habit, micromorphology and MDH patterns were also detected. Chromosome C-banding pattern and results obtained from total genomic DNA in situ hybridization indicate that die different taxa analysed are closely related. The systematic position of the different taxa is analysed.     

Chromosome numbers in Chihuahuan Desert Cactaceae. III. Trans-Pecos Texas

Chromosome numbers are reported for 112 collections of Cactaceae, including 102 collections of Opuntia. Reports are presented for 33 species in five genera and a total of 36 taxa. Two specimens were sterile. Emphasis was given to the documentation of intraspecific ploidy-level consistencies and differences, because of the current poor state of knowledge about the populational integrity of chromosome numbers in Trans-Pecos cacti and because information about ploidy levels is taxonomically significant particularly in certain genera of Cactaceae. First reports are presented for six taxa, including Opuntia aureispina (2n = 11 II), O. tortispina (2n = 33 II), and Ancistrocactus tobuschii (2n = 11 II). Chromosome numbers are now known for all but one or two of the ～104 currently recognized cactus taxa in Trans-Pecos Texas.     

Cytotaxonomic analysis of the Himalayan species of the genusTorilis (Apiaceae)

Chromosome studies of four HimalayanTorilis species reveal a remarkable interand intraspecific differentiation of chromosome numbers and karyotypes:T. arvensis (2n = 12),T. leptophylla (2n = 12),T. Stocksiana (2n = 36) andT. japonica (2n = 16). Base numbers inTorilis are x = 6, 8, 9 and 11.     

A new infraspecific arrangement of Teucrium thymifolium (Lamiaceae), an aggregate endemic to the Iberian Peninsula

In the framework of our studies on Lamiaceae from the eastern Iberian Peninsula, for the forthcoming fourth volume of Flora valentina, a new infraspecific arrangement is proposed here for the Iberian endemic Teucrium thymifolium. Besides the type subspecies, T. thymifolium subsp. thymifolium, which is widely distributed through the eastern Iberian Peninsula, two new nomenclatural combinations are established: (i) T. thymifolium subsp. fraternum (Pau) M.B. Crespo, M.A. Alonso & Mart.-Azorín (= T. terciae), for the thermophilous populations growing in SE Murcia province, and (ii) T. thymifolium subsp. hervieri (Briq. & Debeaux) M.B. Crespo, M.A. Alonso & Mart.-Azorín, for Subbaetic inland populations from where the provinces of Albacete, Jaén and Granada come into contact. Nomenclatural types and data on distribution and ecology are reported for all accepted subspecies, including the designation of a lectotype for T. thymifolium subsp. hervieri. Furthermore, relationships of the latter to the recently described T. moleromesae Sánchez Gómez et al. are briefly discussed, both taxa being treated here in synonymy.     

Chromosome number and ploidy level of some South American species of Schizachyrium (Poaceae, Andropogoneae)

Chromosome numbers are reported here for 53 accessions belonging to 13 taxa of the genus Schizachyrium. The chromosome counts for the following seven species are recorded here for the first time: S. bimucronatum (2n?=?20), S. gracilipes (2n?=?20), S. hatschbachii (2n?=?20), S. lactiflorum (2n?=?20), S. plumigerum (2n?=?20), S. salzmannii (2n?=?20; 2n?=?40) and S. spicatum (2n?=?20). Counts differing from those previously reported are given for two species: S. scabriflorum (2n?=?20 and 80) and S. tenerum (2n?=?40). Most of the analyzed species of this genus are diploids. The occurrence of polyploidy in S. glaziovii, S. lactiflorum, S. salzmanni, S. scabriflorum and S. tenerum is reported here for the first time. Data on chromosome numbers and ploidy levels are discussed in relation to the taxonomy and evolution of the genus.