CHROMOSOME NUMBERS IN THE COMPOSITAE. XII. AUSTRALIAN SPECIES

Chromosome counts are reported for plants from 171 populations of Australian Compositae; most of these are first reports for the approximately 104 taxa distributed among 37 genera. New generic counts with base numbers indicated include: Astereae —Bellida (x = 9), Minuria (x = 9); Inuleae —Angianthus (x = 12, 13), Calocephalus (x = 7), Cephalipterum (x = 12, 14), Craspedia (x = 11), Gnaphalodes (x = 10), Gnephosis (x = 4, 12), Myriocephalus (x = 6), Isoetopsis (x = 17); Calenduleae —Tripteris (x = 8); and Artcoideae —Arctotheca (x = 9). Most of the counts were from the tribes Astereae (47) and Inuleae (95). The phyletic import of these data is discussed selectively and comparisons are made with the chromosomal variation found in the Australian desert Compositae with that found in the North American desert Compositae.     

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 IN SOUTH AMERICAN COMPOSITAE

Original chromosome counts are reported from 91 populations and 73 taxa distributed among 46 genera. Most of these were obtained from meiotic material and are first reports. Some of the more interesting counts are from genera with amphitropical distributions such as Gaillardia and Helenium. When appropriate, systematic implications of the data are discussed.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. XIV. LACTUCEAE

Reports of 150 original chromosome counts are recorded, including reports of 22 genera and 57 species and subspecific taxa in tribe Lactuceae. Also included are first reports for 12 specific or subspecific taxa. x = 9 appears to be the ancestral base of the tribe. Chromosome numbers are known for over 85% of the genera of the tribe and the frequency of polyploidy is ca. 23%, which is about one-half that of the angiosperms.     

CHROMOSOME NUMBERS IN COMPOSITAE VII: ASTEREAE III

Reports of 129 new chromosome counts are made for the tribe Astereae of Compositae. They are mostly based on determinations of meiotic material, including first counts for one genus and 43 species or subspecies. Counts are now available for more than 63 of the 100-120 genera and 564 of the approximately 2,000 species in the tribe. Three of every four genera with more than one species counted show more than one chromosome number; 15 genera have species with populations with different numbers. Such variation is very high and indicates the need for more detailed cytotaxonomical study in the group.     

CHROMOSOME NUMBERS IN COMPOSITAE. X.

Reports of 126 new counts are recorded for 9 tribes of Compositae, including reports for 45 genera and 102 species. Six genera, Psilocarphus (n = 14). Relhania (n = 7), Rutidosis (n = 9), Chaetanthera (n = 14), Hecastocleis (n = 8), and Hesperomannia (n = 10), and 41 species were previously unreported.     

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 COMPOSITAE. XI. HELENIEAE

Reports of 89 new counts are recorded for the tribe Helenieae, including reports for 28 genera and 56 species. One genus, Hypericophyllum (n = 9), and six other taxa were previously unreported.     

CHROMOSOME NUMBERS IN COMPOSITAE. VI. SENECIONEAE. II

Chromosome counts are reported for 76 taxa and 2 natural hybrids of tribe Senecioneae (Compositae). First counts are reported for several species of Senecioneae as well as for the genera Cadiscus and Whitneya. New chromosome numbers are added to those previously known in Arnica, Cacalia, and Senecio. Additional counts from Arnica support our previous suggestion that x = 19 for this genus. It is assumed that observed meiotic irregularities are associated with apomixis in this genus. Basic chromosome numbers for various New World sections of Senecio are proposed, and certain problems of sectional relationships in this genus are discussed. Chromosome numbers and plant morphology of Cadiscus, Hulsea, and Whitneya indicate that these genera should be removed from Helenieae to Senecioneae. The possible affinity of the anomalous genus Adenocaulon with Mutisieae is discussed. Data presented in the paper further support our earlier proposal that the basic chromosome number for Senecioneae is x = 10.     

CHROMOSOME NUMBERS IN SOUTH AMERICAN HAPLOPAPPUS CASS. (COMPOSITAE)

Chromosome counts are reported for 33 species from all four sections of the genus Haplopappus in South America. These include first reports for 28 species and two putative hybrids. All chromosome numbers reported herein are 2n = 5_II, with the exception of H. prunelloides with 2_n = 6_II. Unlike the North American species, the morphological diversity of South American taxa is not concomitant with chromosomal variation.     

CHROMOSOME NUMBERS IN THE LEGUMINOSAE II: AFRICAN SPECIES,INCLUDING PHYLETIC INTERPRETATIONS

Turner , B. L., and O. S. Fearing . (U. Texas, Austin.) Chromosome numbers in the Leguminosae. II. African species, including phyletic interpretations. Amer. Jour. Bot. 46(1) : 49-57. Illus. 1959.—Chromosome numbers for 30 African legume species have been reported. These include first reports for 28 taxa, including 12 genera (Bolusanthus, Calpurnia, Melolobium, Lessertia, Sulherlandia, Colophospermum, Guibourtia, Burkea, Julbernardia, Schotia, Piliostigma and Swartzia). The counts are discussed with respect to those previously reported for related groups, and this chromosomal information was used to construct hypothetical phyletic lines at the tribal level within the subfamilies Papilionoideae and Caesalpinioideae. A phyletic scheme for the Leguminosae (excluding the Mimosoideae) based on this evidence from chromosome studies is presented. Notable departures from previously suggested phyletic treatments include: (1) Suggestion for inclusion of genera of the Galegeae and Hedysareae with base numbers of x = 10 and 11 with the Phaseoleae and Dalbergieae. (2) Derivation of the Papilionoideae through caesalpinoid prototypes, possibly from Swartzia-like ancestors. (3) Recognition of several very old chromosomal lines stemming from the subfamily Caesalpinioideae, and the suggestion that parts of the tribes Sclerolobieae, Cynometreae, Swartzieae and Sophoreae are, perhaps, more closely related to each other and to the Papilionoideae than they are to the remaining caesalpinoid tribal lines.     

CHROMOSOME NUMBERS AND THEIR SYSTEMATIC IMPLICATIONS IN LIPOCHAETA (COMPOSITAE:HELIANTHEAE)

Chromosome counts are reported for 71 collections in 14 taxa of Lipochaeta DC. (Compositae) of the Hawaiian Islands. Counts for 13 of the taxa are first reports. Lipochaeta contains diploids, n = 15, and tetraploids, n = 26. Ploidy level is taxonomically significant for recognizing sections, and on the basis of these data, together with morphological and chemical evidence, major realignments of species into the secions of Lipochaeta have been made.     

CHROMOSOME STUDIES IN COMPOSITAE

Original chromosome observations, including number, from meiotic preparations from 65 collections representing 57 species in 43 genera of Compositae are reported. Of these, eight are first reports. Meiotic irregularities were noted in several species; pollen stainabilities are given for these. Observations that differ from earlier reports are discussed.     

CHROMOSOME NUMBERS AND EVOLUTION IN NORTH AMERICAN SPECIES OF LINUM

Among the North American species of Linum there are three basic chromosome numbers representing invasions from the Old World of three distinct evolutionary lines. N = 9 is found only in the blue-flowered group represented in North America by two species, L. lewisii and L. pratense which are closely related to and may be conspecific with the Old World L. perenne. The basic number for the yellow-flowered species is n = 18 which is characteristic of the Scabrella and Virginiana subgroups. The loss of chromosomes in the Neo-mexicana (n = 13) and Sulcata-Rigida (n = 15) subgroups suggests that the basic haploid number of 18 might be a polyploid derivative of an Old World ancestor with n = 9. The incidence of n = 9 among Old World species of Linum may indicate that this represents an ancestral condition. Linum catharticum has n = 8; this number and features of morphology and distribution suggest that it is not directly related to either the blue-flowered or yellow-flowered groups in North America but represents a separate introduction on this continent.