CHROMOSOME NUMBERS IN THE COMPOSITAE: COLOMBIAN SPECIES

Chromosome numbers are presented for 76 species belonging to 35 genera of Compositae from Colombia. Thirty-nine species and three genera, Espeletia (x = 19), Steiractinia (x = 14), and Vasquezia (x = 19), are reported for the first time. New base numbers or chromosome series are recorded in Baccharis (B. nitida, n = 25), Calea (C. caracasana, n = 24), and Liabum (L. mega-cephalum, n = 10).     

CHROMOSOME NUMBERS IN COMPOSITAE. II. HELENIEAE

Raven , Peter H. (Rancho Santa Ana Botanic Garden, Claremont, Calif.), and Donald W. Kyhos. Chromosome numbers in Compositae. II. Heleniae. Amer. Jour. Bot. 48(9): 842–850. Illus. 1961.—Chromosome counts are now available for 42 of the approximately 55 genera of Compositae, tribe Helenieae, which is predominantly a group of western North America. These chromosome numbers are summarized here at the generic level, and 100 original counts for the tribe are added, including what seem to be the first published reports for the genera Amblyopappus, Baeriopsis, Hulsea, Jaumea, Pericome, Rigiopappus, Trichoptilium, and Venegasia, as well as for many species. The phylogeny of Chaenactis is discussed in the light of published records and 46 original counts, and C. douglasii is shown to include plants in which n = 6, 12, and 18, which differ somewhat morphologically. Helenium has species which have a complete series of aneuploid numbers from n = 13 to n = 17. Chromosome numbers coincide with morphological variability in indicating that Helenieae are a diverse group. More detailed studies of various kinds will be necessary before the genera of Helenieae can be re-aligned effectively, but it is evident that different genera show affinities with various other tribes of the family. Nevertheless, it is thought to be convenient to continue to recognize Helenieae at the tribal level for the present.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. X. NORTH AMERICAN SPECIES

Chromosome counts from 132 plant populations representing 124 taxa (in 67 genera) are reported. These include previously unreported counts for over 70 species and 5 new generic counts (Hofmeisteria, x = 19; Oxypappus, x = 10; Pterocaulon, x = 10; Stenocarpha, x = 8; and Urbinella, x = 8). Two new base numbers are reported for specieis of Perityle (P. californica, x = 13 and P. palmeri, x = 17), and previously unreported n numbers have been found for species of the genera Bidens (n = 17) and Hymenostephium (n = 21). Several gametic cells with differing meiotic configurations were found in the same head of Stevia viscida (n = 11 pairs; 11 pairs and 11 univalents; 33 univalents). When appropriate, the chromosomal information has been related to systematic problems, especially for genera of the subtribes Flaverinae, Coreopsidinae, Galinsoginae and Peritylinae.     

CHROMOSOME NUMBERS AND THEIR SYSTEMATIC IMPLICATIONS IN HAWAIIAN LOBELIOIDEAE (CAMPANULACEAE)

Chromosome numbers are reported for 20 collections of Hawaiian Lobelioideae (Campanulaceae), representing six genera, 13 species, and two interspecific hybrids. All are n = 14. Chromosome numbers are reported for the first time for eight species of Clermontia, Cyanea, Delissea, Lobelia, and Trematolobelia; the report for Delissea is the first for that genus. Additional determinations confirmed previously reported numbers in five other species of Brighamia, Clermontia, and Cyanea. Chromosome numbers are now known for all seven genera and 20 of the 110 species. All accepted counts are n = 14. It is suggested that all Hawaiian Lobelioideae share this number and are paleotetraploid. There is no evidence that the prolific speciation evident among these plants was accompanied by euploid or aneuploid change in chromosome number. The Hawaiian Lobelioideae, particularly the monophyletic lineage of 91 baccate species, offer further support for the generalization that change in chromosome number is an uncommon mode of speciation in insular floras.     

CHROMOSOME NUMBERS IN UMBELLIFERAE. III

Chromosome numbers are reported for 156 collections representing 100 taxa of Umbelliferae. Approximately two thirds of the collections are from Mexico, Central and South America and indicate a high percentage of polyploid species in certain genera found in this area. Chromosome numbers for plants belonging to 78 taxa are published here for the first time, previously published chromosome numbers are verified for 18 taxa and chromosome numbers differing from those previously published are reported in seven instances. No chromosome counts have been previously published for nine of the genera included here. Further aneuploidy and polyploidy were found in Eryngium, and Lomatium columbianum has been found to be a high polyploid with 2n = 14x. Every chromosome count is referable to a cited herbarium specimen.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. IV. NORTH AMERICAN SPECIES,WITH PHYLETIC INTERPRETATIONS

Turner , B. L., W. L. Ellison , and R. M. King . (U. Texas, Austin.) Chromosome numbers in the Compositae. IV. North American species, with phyletic interpretations. Amer. Jour. Bot. 48(3): 216–223. Illus. 1961.—Chromosome counts from 116 different plant populations representing 75 taxa (72 species in 39 genera) are reported. These include the first species counts for the following genera: Actinospermum (x = 19), Baltimora (x =15), Calea (x = ca. 17, 18), Calyptocarpus (x = 12), Hecubaea (x = 17), Lagascea (x = 17), Schistocarpha (x = 8), Melanthera (x = 15), Pectis (x = 12), Perymenium (x = 15), Sanvitalia (x = 8), and Trigonospermum (x = 15). Chromosome counts for Chrysopsis trichophylla (n = 5), Cirsium horridulum (n = 16), Hidalgoa ternata (n = 16,) Tridax balbisioides (n = 10), Tridax trilobata (n = 10), and Verbesina crocata (n =18) differ from the reported basic numbers as determined from other species in these genera. Taxa closely related to Tridax procumbens were found to have the diploid number n = 9, thus establishing the polyploid nature (n = 18) of this widespread polymorphic species. When appropriate, the chromosomal information has been related to systematic problems.     

CHROMOSOME COUNTS OF COMPOSITAE FROM THE UNITED STATES AND MEXICO

Chromosome counts are reported for 126 taxa representing 122 species and 61 genera of Compositae. First reports include two genera, Stylocline (n = 14) and Chromolepis (n = 19), 17 species, two infraspecific taxa, and one interspecific hybrid. Five additional taxa have chromosome numbers differing from previously published accounts. Carminatia is reinstated to generic status.     

CHROMOSOME NUMBERS IN MEXICAN ASTERACEAE

Chromosome numbers are reported for 100 collections distributed among 68 species and 46 genera of Mexican Asteraceae. Included are systematic discussions regarding chromosome numbers of the following taxa: Haplopappus spinulosus var. scabrellus (n = 4, 8); Hofmeisteria fasciculata (n = 19), Malperia tenuis (n = 10), and Pleurocoronis laphamioides (n = 9); Cymophora pringlei (2n = 16); Plummera (n = 15); and Porophyllum tridentatum var. crassifolium (n = 15) as related to Chrysactinia and Nicolletia.     

CHROMOSOME NUMBERS OF CAMPANULACEAE. III. REVIEW AND INTEGRATION OF DATA FOR SUBFAMILY LOBELIOIDEAE

Chromosome numbers are now known for 153 species in 21 genera of Lobelioideae (Campanulaceae); this represents almost 13% of the species and 70% of the genera in the subfamily. Numbers reported are n = 6, 7, 8, 9, 10, 11, 12, 13, 14, 19, 21, 35, 70. The subfamily as a whole has x = 7; the best documented exception is Downingia and its allies with x = 11. Only four genera show interspecific variation in chromosome number: Downingia (n = 6, 8, 9, 10, 11, 12); Lobelia (n = 6, 7, 9, 12, 13, 14, 19, 21); Pralia (n = 6, 7, 13, 14, 21, 35, 70); and Solenopsis (n = 11, 14). Intraspecific variation occurs in 13 species, with as many as four different cytotypes in one species. The herbaceous members of the subfamily as a group are quite variable, showing the entire range of chromosome numbers, including numerous dysploids, but are predominantly diploid. The woody species, by contrast, are much less variable; nearly all of the species are tetraploid, with only a few diploids and hexaploids and no dysploid numbers known. These data support the hypothesis that woodiness is apomorphic within the subfamily. A general trend of higher chromosome numbers at higher latitudes and higher elevations is evident within the subfamily. The chromosome number of Apetahia raiateensis (n = 14) is reported here for the first time, on the basis of a count made about 30 years ago by Peter Raven.     

Chromosome numbers of miscellaneous Malagasy Acanthaceae

Meiotic chromosome numbers are reported for 12 species in eight genera of Acanthaceae from Madagascar. Chromosome numbers of 11 species are reported for the first time. Counts inMendoncia (n=19) andNeuracanthus (n=20) are the first for these genera. A new chromosome number (n=30) is reported inJusticia. Systematic implications of the chromosome counts are addressed and basic chromosome numbers for these eight genera of Malagasy Acanthaceae are discussed.     

Cytotaxonomical studies on AsianAnnonaceae

Chromosome numbers of 42 species and 3 varieties from 24 genera of theAnnonaceae have been determined (Table 1); reports for 15 of the genera are new. Among Asian genera 2n = 14 occurs only in the specializedMezzettia, while 2n = 16 is wide-spread and also has been found inAnaxagorea with some primitive characters. 2n = 18 is reported for 11 genera, and tetraploidy (2n = 36) has been observed inPolyalthia. Therefore, an original basic number of x = 8 or x = 9 is suggested at least for the Asian genera of theAnnonaceae.—Cytotaxonomical notes on the critical speciesPolyalthia rumphii andP. affinis are given, and the new combinationNeouvaria parallelivenia (Boerl.)Okada & Ueda is proposed.     

BIOSYSTEMATIC STUDIES IN THE BOUTELOUA CURTIPENDULA COMPLEX. III. POLLEN SIZE AS RELATED TO CHROMOSOME NUMBERS

Pollen size statistics are presented for 10 closely related species of Bouteloua and relationships between pollen size and chromosome numbers are presented for 13 populations of 5 species and 3 varieties. With 1 exception, all populations of all taxa conformed to a general pattern of pollen size dependent upon chromosome number. Chromosome numbers varied from 2n = 20 to 2n = ca. 103, with several independent aneuploid series. Statistical analyses were made of pollen size as related to chromosome number in the 3 varieties of B. curtipendula. These data showed that tetraploids (2n = 40) of var. tenuis had significantly greater pollen size and coefficient of variation than diploids (2n = 20) of the same variety. Similarly, aneuploids of var. curtipendula with 2n = 45 to 2n = 64 chromosomes had significantly larger and more variable pollen than tetraploids (2n = 40) of the same variety. Highly significant positive regression coefficients were obtained from analyses of chromosome numbers and mean pollen size, and chromosome numbers and coefficient of variation, for var. curtipendula. Regression coefficients for var. caespitosa populations with chromosome numbers over the hexaploid (2n = 60) level were not significant.     

CHROMOSOME NUMBERS IN PERITYLE AND RELATED GENERA (PERITYLANAE-COMPOSITAE)

Chromosome numbers are presented for 28 species of the genus Perityle, one putative inter-sectional hybrid, two species of Amauria, one species of Eutetras, and one species of Pericome. For Perityle, initial counts are recorded for 12 species of sect. Laphamia (n = 16, 17, 18, 36, ca. 102) and 11 species of sect. Perityle (n = 11, 12, 13, 16, 17, 18, 19, 34, 51). Chromosome numbers for the two species of Amauria (n = 18) are first reports for the genus. Including the current information, chromosome numbers have been recorded for 37 of the approximately 50 species recognized for Perityle. At least 24 taxa have numbers of n = 17, suggesting a base chromosome number of x = 17 for Perityle.     

New chromosome counts and evidence of polyploidy in Haageocereus and related genera in tribe Trichocereeae and other tribes of Cactaceae

Chromosome numbers for a total of 54 individuals representing 13 genera and 40 species of Cactaceae, mostly in tribe Trichocereeae, are reported. Five additional taxa examined belong to subfamily Opuntioideae and other tribes of Cactoideae (Browningieae, Pachycereeae, Notocacteae, and Cereeae). Among Trichocereeae, counts for 35 taxa in eight genera are reported, with half of these (17 species) for the genus Haageocereus. These are the first chromosome numbers reported for 36 of the 40 taxa examined, as well as the first counts for the genus Haageocereus. Both diploid and polyploid counts were obtained. Twenty nine species were diploid with 2n=2x=22. Polyploid counts were obtained from the genera Espostoa, Cleistocactus, Haageocereus, and Weberbauerocereus; we detected one triploid (2n=3x=33), nine tetraploids (2n=4x=44), one hexaploid (2n=6x=66), and three octoploids (2n=8x=88). In two cases, different counts were recorded for different individuals of the same species (Espostoa lanata, with 2n=22, 44, and 66; and Weberbauerocereus rauhii, with 2n=44 and 88). These are the first reported polyploid counts for Haageocereus, Cleistocactus, and Espostoa. Our counts support the hypothesis that polyploidy and hybridization have played prominent roles in the evolution of Haageocereus, Weberbauerocereus, and other Trichocereeae.     

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 Compositae. XVIII.

Chromosome numbers and other cytogenetic data were determined from microsporocytes in 316 collections including 13 tribes of Compositae, mostly from Africa, Australia, Mexico, Central America, and South America. First reports are provided for 66 species and the genera Cassinia (2n ≈ 14_II), Feldstonia (2n = 11_II), Gochnatia (2n ≈ 23_II), and Pseudoconyza (n = 10). In addition, new chromosome numbers are established at the generic level in Acourtia, Calea, Craspedia, Gnaphalium, Helipterum, Liabum, Leucheria, Smallanthus, Trixis, and Viguiera and at the specific level in 13 additional species.     

Karyological studies on some Antarctic liverworts

Abstract

Chromosome counts are reported from five species of Antarctic hepatics belonging to five genera and four families. The chromosome numbers in the genera Herzogobryum (H. teres n = 9) and Paehyglossa (P. dissitifolia n = 9) are reported for the first time. The first chromosome count from Lophozia excisa, n = 27, is the highest reported from Lophozia. A diploid number, n = 18, is reported for the first time from Barbilophozia hateheri; a second count, n = 9, agrees with earlier reports. The commonest Antarctic liverwort Cephaloziella cf. exili[lora has n = 18 and this agrees with earlier reports for the genus.     

CHROMOSOME NUMBERS AND TAXONOMIC NOTES FOR ROCKY MOUNTAIN UMBELLIFERAE

Chromosome numbers are reported for 111 collections of Umbelliferae, which represent 38 species belonging to 23 genera. Three of these genera, Aletes, Neoparrya, and Musineon, have not been counted previously. In addition, first counts are presented for Angelica grayi, A, roseana, Cymopterus acaulis, C. bulbosus, C. longipes, C. montanus, Lomatium foeniculaceum subsp. macdougalii, L. megarrhizum, L. nuttallii, L. orientate, and L. simplex. Our reports of polyploidy in Ligusticum ported (hexaploid, 2n = ca. 66) and in Pteryxia terebinthina var. calcarea (tetraploid, 2n = 44) are the first for these taxa. The counts of 2n = 22 for Harbouria trachypleura differ from the previous report of 2n = 20.     

Karyological knowledge of the Italian vascular flora as inferred by the analysis of “Chrobase.it”

Abstract

Chromosome number knowledge of the Italian vascular flora is stored in the online database Chrobase.it, which includes 6723 records, referable to 3428 taxa, 2799 accepted species and subspecies (about 35% of the national flora), and 3410 different chromosome countings (cytotypes). Appropriate queries to Chrobase.it allowed us to calculate mean, modal and median chromosome numbers for the Italian vascular flora, for geographical subgroups (islands, south, centre, north) and for selected orders, families and genera. Chromosome number data were available for 41 out of 55 orders (74%) and 107 out of 428 families (67%), represented by 664 out of 1297 genera (51%). The most studied administrative regions are Sicily (844 taxa), Tuscany (592 taxa), and Sardinia (390 taxa), while the most studied families are Asteraceae (465 taxa), Fabaceae (266 taxa), Brassicaceae (158 taxa), and Poaceae (144 taxa). Chromosome numbers range from 2n = 6, occurring in several species of Hypochaeris (Asteraceae), to 2n = 240, occurring in Ophioglossum (Ophioglossaceae), Dryopteris (Dryopteridaceae) and Arenaria (Caryophyllaceae) (mode is 2n = 18, and median is 2n = 24). Chromosome number variability was analyzed by frequencies (linear plots) and ANOVA, resulting in significant differences among geographical groups (mean chromosome number increasing from islands-south to centre-north) and selected taxa. B-chromosomes occur in 5.3% of data (148 taxa) and their number is not significantly different among geographical areas, while they occur only in 14 orders, 17 families, and 56 genera. The number of B-chromosomes ranges from 1 to 13 (mode = 1, median = 2).     

A CYTOTAXOXOMIC SURVEY OF MELAMPODIUM (COMPOSITAE-HELIANTHEAE)

Turner , B. L.. and R. M. King . (U. Texas, Austin.) A cytotaxonomic survey of Melampodium (Compositae-Heliantheae). Amer. Jour. Bot. 49(3): 233–26. Illus. 1962.—Chromosome counts are reported for individuals from 89 populations of Melampodium representing 26 species The genus is multibasic with x = 9, 10, 11, 12, 16 and 23. Chromosome numbers on a base of x = 10 characterize the section Melampodium while basic numbers of x = 23, 16, 12, 11 and 9 occur in the section Zarabellia. Melampodium camphoratum (n = 16) differs from all other species examined in having relatively small meiotic chromosomes. Only 6 of the 23 species are polyploid or have polyploid races. Melampodium leucanthum and M. cinereum have both diploid and tetraploid populations; the latter occur without any apparent morphological or geographical correlation and are probably autoploid in origin. A survey of the basic chromosome numbers known for other genera of the subtribe Melampodinae (12 of 22 genera) is presented. and it is suggested that x = 10 is the most probable basic number of the genus and subtribe.